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Plant-made vaccines and reagents for SARS-CoV-2 in South Africa

4 April, 2020

Plant-Made Vaccines and Therapeutics

I have published a number of reviews on plant-made vaccines (see below), and our Biopharming Research Unit (affectionately known as “The BRU”) has been very active in this research area for nearly twenty years now. The theme running through all our publications is always “Plants are a cheaper, faster, safer and more scalable means of producing pharmaceutically-relevant proteins than any of the conventional expression systems…” Since 2003 we have published 50-odd articles on plant-made recombinant proteins, including human and animal vaccine proteins and enzymes, so we have used this justification a lot.

Which begs the question, why isn’t Big Pharma using plant plant production, then?

After all, it’s been 30-odd years since the first “molecular farming” product was made, and many proofs of principle and several of efficacy of therapeutics and vaccines have been obtained, yet the pharmaceutical world has just two products that have been licenced or emergency licenced for use in humans. The first is Elelyso from Pfizer, better known in molecular farming circles as glucocerebrosidase developed by Protalix, which is an enzyme replacement therapeutic for persons suffering from Gaucher disease. This is not strictly speaking a plant product, though, as it is made in transgenic suspension cultured carrot cells, in 800 litre plastic bags.

The other is ZMapp, which is a cocktail of three “humanised” monoclonal antibodies (mAbs) which bind to Ebola virus, made by transient expression in Nicotiana benthamiana plants, and which were used in people as a post-infection therapy in the West African Ebola disease outbreak from 2014-2016.

If you consider that the first products to receive regulatory body approval – both in 2006 – were a mAb to hepatitis B virus surface antigen (HBsAg) that was used in purification by a Cuban company of the protein from yeast culture lysates, and tobacco suspension culture-produced Newcastle disease virus vaccine made for Dow AgroSciences that was never marketed, there has been effectively no market breakout at all for plant-made pharmaceuticals (PMPs).

Why is this? Why is it that a technology that can produce biomass containing product-of-interest between 100 and 1000 times more cheaply than mammalian CHO cells, or 10 – 100-fold cheaper than yeast or bacterial cultures, and be scaled from lab to industrial levels of production quicker than any other system, still languishing in the biotech industry doldrums?

Rybicki, 2009: Drug Discov Today. 2009 Jan;14(1-2):16-24. doi: 10.1016/j.drudis.2008.10.002

Granted, biomass production is only the upstream part of pharmaceutical production; the downstream purification / refinement / vialling and packaging costs for plant-made products will be the same as for conventionally-made versions, and these are typically much higher than biomass production costs. My own back-of-the-envelope calculations, done at a conference I attended where these costs were broken down by an industry expert, came out with plant-made finished product in a vial being 32% cheaper than the conventional equivalent. Given the large markup on finished product, this “advantage” is in itself not sufficient motivation for Big Pharma to change the means of production, given their typically enormous investments in stainless steel and other infrastructure.

And yet…doubling production capacity for any given product by a single Big Pharma supplier using conventional cell culture technology would entail spending the same amount again to get more stainless steel – which is typically multiples of at least US$100 million – as well as spending an inordinately long time getting the new plant certified. Also, even making a new product from scratch using existing infrastructure would involve heroic cleaning and rejigging of tanks and feed pipes and other paraphernalia used for biomass production, recertifications and the like, which could take months.  With plant-based manufacture, on the other hand, doubling production capacity means using double the number of cheaply-grown plants, possibly doubling the volume of Agrobacterium tumefaciens suspension to dunk them into, and then having enough space to put them under lights for 5-7 days or so, all with the same downstream processing capacity.

Then, there is the speed of scalability, which is unmatched for plant-made proteins. Consider this: given a ready supply of plants, it is theoretically possible for a molecular farming industrial facility to scale plant production of any given protein from lab bench scale – say a few milligrams/batch –  to industrial scale (kilograms per batch), in as long a time it takes to culture the few hundred litres of Agrobacterium you would need for infiltration. Keeping a large reserve of plants is cheap; commercial greenhouses could do this very cheaply – meaning biomass is effectively instantly available to whatever volume required. Culturing Agrobacterium to scale would also literally take a couple of days, meaning infiltrating and incubation for target molecule synthesis could take just a few days from obtaining a gene. Scaling a new line of stably transfected CHO cells from a flask up to 30 000 litres, on the other hand…this takes many cell doublings, with the attendant problems of maintaining both genetic integrity and sterility, and is far more expensive and takes longer.

Plant-Made COVID-19 / SARS-CoV-2 Vaccines

In fact, in 2012 as part of the DARPA “Blue “Angel” challenge, Medicago Inc. of Quebec in their new North Carolina facility, managed to make 10 million doses of H1N1 influenza virus vaccine as virus-like particles (VLPs), vialled and labelled, within a month of being given the sequence of the virus. If one considers that seasonal influenza vaccines take at least six months to make by egg culture, even with accelerated clinical testing and certification, this is a truly impressive improvement on current technology, and probably the quickest development of an influenza virus vaccine ever*. The company has since advanced to making and testing a quadrivalent seasonal influenza vaccine candidate through Phase III clinical trial, for imminent commercial release, was awarded “Best New Vaccine Technology/Platform” prize at the World Vaccine Congress in 2019 – and on March 12th 2020 announced they had made a viable vaccine candidate against COVID-19. They did this in just 20 days after receiving (presumably) the S envelope glycoprotein gene, and moreover made VLPs using their proprietary technology: VLPs are better immunogens than soluble subunit proteins, as they are much better at stimulating both antibody and cellular immune responses.

Virus-like particles made the same way Medicago will probably make SARS-CoV-2 VLPs – from this paper: https://zoom.us/j/313676518?pwd=bnFrQmxtR3l2TjY4VGFWWEhjZklnZz09

They are not alone in this space: just two weeks later, British American Tobacco (BAT) gained a lot of media attention when they also announced a candidate plant-made vaccine against SARS-CoV-2. While many hailed the repurposing of tobacco by a cigarette-manufacturing company as being an unexpected and good thing, it was really the BAT subsidiary RJ Reynolds’ recent purchase of Kentucky BioProcessing Inc, itself a spinout of one of the pioneering molecular farming companies (Large Scale Biology Inc., now sadly defunct) and the firm that had produced the largest amounts of the anti-Ebola ZMapp mAbs, that allowed them to take the credit. History aside, KBP announced they had “cloned a portion of COVID-19’s genetic sequence to create an antigen, which induce an immune response in the body” – which almost certainly means the S glycoprotein, or a portion of it – and that they could potentially make 3 million doses a week.

These announcements are the most important in the molecular farming space – although there have been others, such as by my long-time friend George Lomonossoff in the UK –  and the vaccine candidates are almost certainly going to be cheaper and quicker to make than conventionally manufactured subunit-based equivalents like the Coalition for Epidemic Preparedness Innovations (CEPI)-sponsored University of Queensland product announced recently. Indeed, a local “futurist” – Pieter Geldenhuys, interviewed by Moneyweb on 29th March – said, of the news that Medicago had developed a vaccine:

“Once one of the multitude of medical research teams have developed an effective vaccine for the strain prevalent in South Africa, it will take several months, or even years, before enough vaccines could be produced to fill the global need. This is where tobacco plants come in”

Geldenhuys’s advice for various governments around the world is clear. Keep your ear on the ground and start reaching out to companies like these. Once initial tests show success, consider building your own tobacco cultivation plants to ensure that you can reproduce the vaccine at speed.

A very recent article in the Wall Street Journal also soberly assesses the prospects of plant-made vaccines against SARS2 – with some help from some molecular farmers we may know B-)

Molecular Farming Manufacturing Possibilities in South Africa

Our group in the BRU, our recent spinout partners* Cape Bio Pharms, and a group at the SA Council for Scientific and Industrial Research (CSIR) are the three premier molecular farming research and development teams in South Africa. We have jointly made a host of candidate vaccines, virus-derived reagents for use in molecular biology labs and in diagnostics, and mAbs for use as reagents and potentially as therapeutics. Presently, Cape Bio Pharms and possibly the CSIR represent the only pilot-scale manufacturing facilities in South Africa for plant-made biologics, despite initiatives over years involving us and the CSIR and various government departments. A symposium in Franschhoek in the Western Cape Province in November 2017, hosted by the BRU and by iBio Inc of Bryan Texas, pitched a plan to assembled invited delegates for public/private partnership to construct a facility in this country to make pharmaceutical products using molecular farming technology. In announcing it, we said the following:

iBio’s plant growth facility, October 2018

“The conference brings together leaders from public agencies, academic institutions, parastatals, private companies, regulators and private capital to map out concrete steps to establish the plant-based manufacturing platform in South Africa. The Department of Science and Technology (DST) leads a broad science and technology innovation effort including of advanced health care products to create socio-economic opportunities.   The Technology Innovation Agency (TIA) is an active funder of human and animal health care initiatives in South Africa.     The Industrial Development Corporation (IDC) is a primary developer of manufacturing capacity and has important initiatives in biotechnology. Other participating agencies include the Council for Scientific and Industrial Research (CSIR), with its own molecular farming pipeline, and the Department of Trade and Industry (DTI).

AzarGen Biotechnologies is a private South African biotechnology company will be part of the private sector representation. AzarGen, primarily funded by the IDC, has worked with iBio for the last three years to develop biotherapeutics that include surfactin for infant respiratory distress syndrome and a biobetter rituximab monoclonal antibody for the treatment of non-Hodgkin’s lymphoma and certain autoimmune diseases. The BioVac Institute and Onderstepoort Biologicals, manufacturers of human and animal vaccine products respectively, will also present. ENSafrica will speak to Intellectual Asset Management and Cape Venture Partners will overview the private capital opportunities in South Africa. Technology Innovation Group, a US based consulting group, will talk about the structure of successful public/private partnerships.”

While the idea of a full-scale facility similar to iBio’s – costed at around USD30 million/R450 million – did not appeal to funders present, the idea of a cGMP-certified pilot manufacturing facility costing USD10 million – R150 million at the time – constructed using iBio’s expertise and assistance, found more favour. In fact, various entities promised to survey interested parties to establish the need and feasibility of internally funding it.

To the best of my knowledge, nothing along the lines of a survey has happened to date. Since then, and in the absence of any apparent interest from what were DST, DTI, IDC, TIA and others, iBio has gone on in 2019 to announce a partnership with Azargen in the area of rituximab biosimilar production, and as of a few days ago, as a contract manufacturing organisation, is offering their services in making COVID/SARS2 reagents at industrial scale in plants. Cape Bio Pharms has also established itself as a reagent manufacturer independently of any outside associations, with only local investment and a THRIP grant from Dept of Trade and Industry (DTI). I note that a previous proposal from some years ago involving the CSIR and Kentucky BioProcessing for establishment of an even cheaper pilot facility, also fell flat. For comparison, I will point out that the cost of just the revamping of Onderstepoort Biological Products’ (OBP, SA’s premier veterinary vaccine manufacturer) facility to be able to achieve cGMP certification is estimated to be ~R500 million.

SARS2/COVID Vaccines and Reagents for South Africa

Very early on in the present pandemic, Dr Mani Margolin of both the BRU and the Vaccine Research Group (VRG) of Prof Anna-Lise Williamson ordered a synthetic gene for a soluble version of the SARS-CoV-2 S protein, and has since successfully expressed the protein in both tissue cultured human cells, and in Nicotiana benthamiana plants via transient Agrobacterium-mediated expression. Both expression strategies leveraged technologies for which our research groups have either applied for or been granted patents, and established the very real possibilities of making both a DNA vaccine and a protein subunit vaccine against SARS2. He has gone on to insert the S protein gene into other vaccine vectors in the VRG.

Cape Bio Pharms (CBP)*, acting in parallel, ordered a gene for the “head” portion of the S protein – termed S1 – which they have also successfully expressed in N benthamiana, along with several variants of the protein, and they plan to collaborate with another new biotech company in South Africa to use it to produce mAbs for use as reagents, and potentially as therapeutics.

The CSIR is planning to leverage their established expertise in making mAbs to HIV and rabies in plants to produce a panel of mAbs to SARS2 for the same purposes.

These efforts have already resulted in ad hoc partnerships with other research groups and organisations, with S and S1 protein being supplied to others for use in establishing enzyme immunoassays and other diagnostic tests for serosurveillance and bedside testing, and other genes being shared with us and CBP for expression as reagents. I will note that the efforts that have resulted in the S-derived products are probably the fastest production at scales greater than a few micrograms in this country of any protein-based reagents, and probably the most quickly and cheaply scalable of any reagents. We are presently awaiting news of possible funding for molecular farming projects involving SARS2, albeit in a very rapidIy changing landscape where every day brings new developments – and where the future economic prospects of our country look dire, which may work against us.

Lessons From the Past

We have been here before, though. In 2006 our group received “Emergency Response” 1-year funding for H5N1 vaccine development from the Poliomyelitis Research Foundation (PRF) in SA – a then-handsome amount of R250 000 – which we then parlayed into another PRF 3-year grant, as well funding from the SA Medical Research Council (SAMRC). This quote from a profile published in Human Vaccines & Immunotherapeutics nicely sums up what we did:

As a result of a conference held in Cape Town in 2005, where a WHO influenza expert warned us “When the pandemic comes, you in the developing countries will be on your own”, we applied for extraordinary funding from the PRF in SA to explore the possibility of making a pandemic flu virus vaccine in South Africa. We chose the highly pathogenic avian influenza virus A H5N1 type haemagglutinin (H5 HA) as a target, and James Maclean was again instrumental in designing and successful early testing of plant-made soluble and membrane-bound forms. Further funding from the PRF and the SA MRC allowed proof of principle that we could in fact produce flu virus vaccine candidates in South Africa – both as [plant-made] subunit protein and as DNA vaccines.

In retrospect, while these projects were impossibly ambitious and not a little naïve, we and our co-workers received a crash course in both research vaccinology and the handling of big projects that has been crucial for all our subsequent work. We were also able to establish stable and well-qualified teams of people, with a nucleus of senior scientists who have been around us for up to 15 years. Another very important lesson was that we should patent our discoveries: in my case, this has led to me and my co-workers having the largest patent portfolio at our institution, and the largest molecular biotechnology-related portfolio in Africa – most of them to do with vaccines (14+ patent families). The development of a set of well-tried protocols around expression of novel antigens in a variety of systems has also been invaluable – especially when funding circumstances demanded that we change direction….

The potential importance of molecular farming for human health has been underlined recently with the apparently successful use of plant-produced MAbs (ZMapp) against Ebola virus disease in West Africa, and the proof of large-scale and rapid emergency-response production in plants of potentially pandemic influenza vaccines by Medicago Inc, among others [my emphasis] . We see our future role in exploiting niche opportunities for production of vaccine candidates and reagents for orphan or geographically-limited disease agents that do not attract Big Pharma attention – like CCHFV and RVFV – as well as for emerging animal diseases such as BTV and AHSV and BFDV, where rapid responses and small manufacturing runs may be needed [my emphasis].

Despite the fact that we ambitiously entitled our 2012 flu vaccine paper “Setting up a platform for plant-based influenza virus vaccine production in South Africa“, and our 2013 DNA vaccine paper as “An H5N1 influenza DNA vaccine for South Africa“, nothing happened. Nothing, despite the then Minister of Health Dr Aaron Motsoaledi saying during the influenza H1N1 2009 pandemic, that:

“South Africa has arrived at a situation where we have no option but to start developing our own vaccine capacity, not only for H1N1, but generally,” Motsoaledi told parliament.

“The disturbing feature about today’s world… has been expressed by the minister of health for Cambodia… who noted that the developed world, after producing the vaccine, may want to cover their own population first before thinking about the developing world,” Motsoaledi said.

It’s been nearly 11 years. Nothing has happened still. Despite distributing some 25 million doses of vaccines annually in South Africa, our only human vaccine firm – The Biovac Institute – still makes no virus vaccines. We have licenced our patented technology – for plant-made human papillomavirus vaccines and influenza virus vaccine – outside the country, for the lack of any interest locally.

This really should change. Maybe we have an opportunity now.

*= potential conflicts of interest due to partnerships.

Reviews on Molecular Farming

1: Dennis SJ, Meyers AE, Hitzeroth II, Rybicki EP. African Horse Sickness: A Review of Current Understanding and Vaccine Development. Viruses. 2019 Sep 11;11(9). pii: E844. doi: 10.3390/v11090844. Review. PubMed PMID: 31514299; PubMed Central PMCID: PMC6783979.

2: Rybicki EP. Plant molecular farming of virus-like nanoparticles as vaccines and reagents. Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2020 Mar;12(2):e1587. doi: 10.1002/wnan.1587. Epub 2019 Sep 5. Review. PubMed PMID: 31486296.

3: Chapman R, Rybicki EP. Use of a Novel Enhanced DNA Vaccine Vector for Preclinical Virus Vaccine Investigation. Vaccines (Basel). 2019 Jun 13;7(2). pii: E50. doi: 10.3390/vaccines7020050. Review. PubMed PMID: 31200559; PubMed Central  PMCID: PMC6632145.

4: Margolin E, Chapman R, Williamson AL, Rybicki EP, Meyers AE. Production of complex viral glycoproteins in plants as vaccine immunogens. Plant Biotechnol J.  2018 Jun 11. doi: 10.1111/pbi.12963. [Epub ahead of print] Review. PubMed PMID: 29890031; PubMed Central PMCID: PMC6097131.

5: Chabeda A, Yanez RJR, Lamprecht R, Meyers AE, Rybicki EP, Hitzeroth II. Therapeutic vaccines for high-risk HPV-associated diseases. Papillomavirus Res. 2018 Jun;5:46-58. doi: 10.1016/j.pvr.2017.12.006. Epub 2017 Dec 19. Review. PubMed PMID: 29277575; PubMed Central PMCID: PMC5887015.

6: Rybicki EP. Plant-made vaccines and reagents for the One Health initiative. Hum Vaccin Immunother. 2017 Dec 2;13(12):2912-2917. doi: 10.1080/21645515.2017.1356497. Epub 2017 Aug 28. Review. PubMed PMID: 28846485; PubMed Central PMCID: PMC5718809.

7: Williamson AL, Rybicki EP. Justification for the inclusion of Gag in HIV vaccine candidates. Expert Rev Vaccines. 2016 May;15(5):585-98. doi: 10.1586/14760584.2016.1129904. Epub 2015 Dec 28. Review. PubMed PMID: 26645951.

8: Rybicki EP. Plant-based vaccines against viruses. Virol J. 2014 Dec 3;11:205.  doi: 10.1186/s12985-014-0205-0. Review. PubMed PMID: 25465382; PubMed Central PMCID: PMC4264547.

10: Scotti N, Rybicki EP. Virus-like particles produced in plants as potential vaccines. Expert Rev Vaccines. 2013 Feb;12(2):211-24. doi: 10.1586/erv.12.147. Review. PubMed PMID: 23414411.

11: Thuenemann EC, Lenzi P, Love AJ, Taliansky M, Bécares M, Zuñiga S, Enjuanes L, Zahmanova GG, Minkov IN, Matić S, Noris E, Meyers A, Hattingh A, Rybicki EP, Kiselev OI, Ravin NV, Eldarov MA, Skryabin KG, Lomonossoff GP. The use of transient expression systems for the rapid production of virus-like particles in  plants. Curr Pharm Des. 2013;19(31):5564-73. Review. PubMed PMID: 23394559.

12: Rybicki EP, Hitzeroth II, Meyers A, Dus Santos MJ, Wigdorovitz A. Developing  country applications of molecular farming: case studies in South Africa and Argentina. Curr Pharm Des. 2013;19(31):5612-21. Review. PubMed PMID: 23394557.

14: Lotter-Stark HC, Rybicki EP, Chikwamba RK. Plant made anti-HIV microbicides–a field of opportunity. Biotechnol Adv. 2012 Nov-Dec;30(6):1614-26. doi: 10.1016/j.biotechadv.2012.06.002. Epub 2012 Jun 28. Review. PubMed PMID: 22750509.

15: Rybicki EP, Martin DP. Virus-derived ssDNA vectors for the expression of foreign proteins in plants. Curr Top Microbiol Immunol. 2014;375:19-45. doi: 10.1007/82_2011_185. Review. PubMed PMID: 22038412.

16: Rybicki EP, Chikwamba R, Koch M, Rhodes JI, Groenewald JH. Plant-made therapeutics: an emerging platform in South Africa. Biotechnol Adv. 2012 Mar-Apr;30(2):449-59. doi: 10.1016/j.biotechadv.2011.07.014. Epub 2011 Aug 3. Review. PubMed PMID: 21839824.

17: Rybicki EP, Williamson AL, Meyers A, Hitzeroth II. Vaccine farming in Cape Town. Hum Vaccin. 2011 Mar;7(3):339-48. Epub 2011 Mar 1. Review. PubMed PMID: 21358269.

18: Giorgi C, Franconi R, Rybicki EP. Human papillomavirus vaccines in plants. Expert Rev Vaccines. 2010 Aug;9(8):913-24. doi: 10.1586/erv.10.84. Review. PubMed PMID: 20673013.

19: Rybicki EP. Plant-made vaccines for humans and animals. Plant Biotechnol J. 2010 Jun;8(5):620-37. doi: 10.1111/j.1467-7652.2010.00507.x. Epub 2010 Mar 11. Review. PubMed PMID: 20233333.

20: Pereira R, Hitzeroth II, Rybicki EP. Insights into the role and function of L2, the minor capsid protein of papillomaviruses. Arch Virol. 2009;154(2):187-97. doi: 10.1007/s00705-009-0310-3. Epub 2009 Jan 25. Review. PubMed PMID: 19169853.

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Purifying TMV: a blast from the archives

16 February, 2017

We have had an in-house method for purifying Tobacco mosaic virus (TMV) and its various relatives ever since I got to Cape Town – and it was propagated by copying and re-copying of what was effectively an abstract for a talk given at our local Experimental Biology Group quarterly meeting in early 1970, published in the South African Medical Journal.

Marc van Regenmortel was Professor of Microbiology at the time, and had a long history of physicochemical and serological work on TMV and strains and mutants of TMV. He also had Barbara von Wechmar, later to become my PhD supervisor, working for him as a Scientific Officer – and together they came up with an ingeniously simple, easy, high-yielding method to purify TMV out of infected tobacco.

So why do we care now? Well, we’re trying to purify some derivatised TMV [details redacted while patent is sought], and Sue Dennis in my lab could only find techniques that involved extraction with chloroform, PEG/salt precipitation x 2, high-speed centrifugation – all of which sounded unnecessarily laborious, given I knew we had a better method.

Trouble is – I cleaned up my office a while back, and seeing as “we’ll never work with TMV again, will we??”, I’d thrown out all of the old practical manuals that included it.

So I go to the old papers I could find online, and they all referred to “von Wechmar and van Regenmortel, 1970”, with no methodological details. And of course, there was no record of this paper anywhere I could find, not even using [obscure Russian language site details redacted].

Then I chanced upon the very bare bones online archive of the SAMJ, married that up with the much snazzier-looking-but-devoid-of-desired pdfs official site to find issue numbers – and there we were! Via some fascinating side trips through a history of the plague in Cape Town, among other things, but finally, a PDF of the original EBG abstract.

tmv-method

In fact, I have a big section of our coldroom with myriad bottles of purified TMV, all at 5 mg/ml concentration or higher, still infectious, and up to 40 years old – all made by this technique.

tmv sedim

So Sue is about to apply it right now, as she conveniently has a freshly mashed extract of N benthamiana ready waiting, and we have PEG and NaCl…we’ll give the charcoal/Celite a miss this time, because it can get a bit messy, but it is THE way to get pigments out of your virus preps – or even nanoparticles, @FrankBioNano & @Lomonossoff_Lab?

Posted in biofarming, biotechnology, General Virology, history, plant viruses, Teaching, techniques | Leave a Comment »

From plant virology to vaccinology: a personal journey

15 February, 2017

A couple of years ago now, an Editor of the journal Human Vaccines & Immunotherapeutics contacted me to say they would like to profile me as a vaccinologist. Being of a suspicious nature, I immediately inquired how much this would cost me. The encouraging answer was “Nothing!” – so I jumped straight in.

The end result is as near to a current autobiography as I will probably ever get, so I may as well put it up here. So, if you’re interested in finding out what the connections are between a swimming pool in Zambia, not doing Biochemistry (twice), plant virology and making vaccines – click below!

From plant virology to vaccinology: The road less travelled

Posted in biofarming, biotechnology, geminivirus, General Virology, GMOs, history, HIV, HPV, Influenza viruses, plant viruses, Teaching, techniques, Vaccines: General | 4 Comments »

Fall armyworm – and how viruses could help combat the plague.

15 February, 2017

Kenneth Wilson of the Univ of Lancaster has recently written a blog post on the plagues of African and “Fall” armyworms (aka caterpillars, larvae of moth species in the genus Spodoptera) that are currently chewing their way through southern African maize and other crops. I wrote the following as a comment to his blog.

Nice article – which very ably demonstrates the perils of importing agricultural pests from elsewhere!

I am interested that you wrote:
“There are non-chemical, biological pesticides that could also be effective. These are pesticides derived from natural diseases of insects, such as viruses, fungi and bacteria.”

Some years back (OK, nearly 30) Barbara von Wechmar in the then Microbiology Dept was instrumental in our finding a number of insect viruses that were seriously lethal to aphids and green stinkbugs. These were inadvertent discoveries, which happened three times – twice with different viruses for aphids which we were investigating as wheat/barley pests, and once (with two viruses) for stinkbugs causing problems in passionfruit – and were due to observations that high density lab colonies of the insects in question often developed disease that caused rapid colony death. Barbara went on, after characterisation and publication of the viruses by me and Carolyn Williamson, to show that highly effective insecticides could be made by simply grinding up recently dead insects in some buffered saline, sieving the bits out, and spraying the juice onto plants. This worked for aphids, and was especially effective for stinkbugs.

I note that similar phenomena have been seen for a number of insects, including the spruce budworm in North America, and by Don Hendry and others in South Africa for Nudaurelia capensis, the Pine Emperor moth. In the latter case, the larvae can become literal sacs of virus, and bursting of dead caterpillars leaves viruses everywhere in the environment.

It might be a good “boer maak n’plan” type of approach for folk to gather a bucket of these things, feed ’em leaves for a while, see if they start to die – then mulch them in some half-strength (=0.075M) saline and make a spray out of it.

It couldn’t hurt, might help, and would be a pretty good biology lesson B-)

Seriously: you can find insect viruses everywhere you look, and crowding is a really good way of spreading and bringing out otherwise inapparent virus infections, just as it is with humans – with the difference being that insect viruses can reach REALLY high titres in their hosts, and are pretty stable as they are often spread by contact of live larvae with dried juices from dead ones.

References

John C. Cunningham, Basil M. Arif and Jean Percy. THE STATUS OF VIRUSES FOR SPRUCE BUDWORM POPULATION REGULATION. File Report No. 7 January 1981, Forest Pest Management Institute, Canadian Forestry Service

EP Rybicki and MB von Wechmar. Characterisation of an Aphid-Transmitted Virus Disease of Small Grains. Isolation and Partial Characterisation of Three Viruses. J Phytopathology 103, Issue 4 April 1982 Pages 306–322

Cheryl T. Walter, Michele Tomasicchio, Valerie Hodgson, Donald A. Hendry, Martin P. Hill and Rosemary A. Dorrington.  Characterization of a succession of small insect viruses in a wild South African population of Nudaurelia cytherea capensis (Lepidoptera: Saturniidae). South African Journal of Science 104, March/April 2008

C. WILLIAMSON, E. P. RYBICKI, G. G. F. KASDORF  AND M. B. VON WECHMAR. Characterization of a New Picorna-like Virus Isolated from Aphids. J. gen. Virol. (1988), 69, 787-795

Williamson C, von Wechmar MB. Two novel viruses associated with severe disease symptoms of the green stinkbug Nezara viridula. J Gen Virol. 1992 Sep;73 ( Pt 9):2467-71.

 

Posted in biotechnology, Teaching, techniques, Vaccines: General, Viruses | 1 Comment »

The Internet Journal of Comprehensive Virology

15 July, 2016

 

See Home Page for details

Posted in biofarming, biotechnology, Ebola, Ebola, Evolution, geminivirus, General, General Virology, GMOs, HIV, HPV, Influenza viruses, Marine Viruses, phages, plant viruses, prions, techniques, Vaccines: General, Viruses | 1 Comment »

New developments in a South African HIV vaccine trial

7 June, 2016
HIV life cycle - Russell Kightley Media

HIV life cycle – Russell Kightley Media

Subtype C gp140 Vaccine Boosts Immune Responses Primed by the South African AIDS Vaccine Initiative DNA-C2 and MVA-C HIV Vaccines after More than a 2-Year Gap 

A phase I safety and immunogenicity study investigated South African AIDS Vaccine Initiative (SAAVI) HIV-1 subtype C (HIV-1C) DNA vaccine encoding Gag-RT-Tat-Nef and gp150, boosted with modified vaccinia Ankara (MVA) expressing matched antigens. Following the finding of partial protective efficacy in the RV144 HIV vaccine efficacy trial, a protein boost with HIV-1 subtype C V2-deleted gp140 with MF59 was added to the regimen. A total of 48 participants (12 U.S. participants and 36 Republic of South Africa [RSA] participants) were randomized to receive 3 intramuscular (i.m.) doses of SAAVI DNA-C2 of 4 mg (months 0, 1, and 2) and 2 i.m. doses of SAAVI MVA-C of 1.45 × 109 PFU (months 4 and 5) (n = 40) or of a placebo (n = 8). Approximately 2 years after vaccination, 27 participants were rerandomized to receive gp140/MF59 at 100 μg or placebo, as 2 i.m. injections, 3 months apart. The vaccine regimen was safe and well tolerated. After the DNA-MVA regimen, CD4+ T-cell and CD8+ T-cell responses occurred in 74% and 32% of the participants, respectively. The protein boost increased CD4+ T-cell responses to 87% of the subjects. All participants developed tier 1 HIV-1C neutralizing antibody responses as well as durable Env binding antibodies that recognized linear V3 and C5 peptides. The HIV-1 subtype C DNA-MVA vaccine regimen showed promising cellular immunogenicity. Boosting with gp140/MF59 enhanced levels of binding and neutralizing antibodies as well as CD4+ T-cell responses to HIV-1 envelope. (This study has been registered at ClinicalTrials.gov under registration no. NCT00574600 and NCT01423825.)

This is a pretty big deal – because it reports an extension of a wholly South African-originated vaccine trial, that consisted of a DNA prime with a subtype C gp150 gene and an artificial Gag-RT-Tat-Nef polyprotein gene, followed by a rMVA boost, that was as immunogenic as anything else trialled around the same time.

And development of which was shut down for political reasons in 2009, but that is old news….
This new development, where a subtype C gp140 (soluble form of Env) was given with MF59 adjuvant to trial participants 2 years after the initial vaccinations, showed that recall responses were strong – in both cellular and humoral arms of the immune system. Moreover, neutralising Ab were elicited.
This is a very promising development in the saga of HIV vaccinology, and it is to be hoped that further trials will be funded.
And both my sister-in-law and my wife are involved B-) What can I say, we’re a virological family!

Posted in biotechnology, Evolution, General Virology, GMOs, HIV, Vaccines: General, Viruses | Leave a Comment »

AIDS: 35 years old this month

6 June, 2016
HIV particle. Russell Kightley Media

HIV particle. Russell Kightley Media

I was alerted via Twitter this morning to the fact that the CDC’s Morbidity and Mortality Weekly report that reported the first recognition of the syndrome we now know as AIDS, was published on 5th of June 1981.  It appears – sadly – that their archive only goes back to 1982: there’s a missed chance to expose some history, CDC?!

Thirty five years: I was a novice lecturer, just starting out; the Web was still science fiction; HIV and its relatives were still undiscovered – but they had already started to spread out of Africa, after smouldering away in the tropical forests of Gabon and the Congos for decades.

I started an information web page on HIV/AIDS back in 2000 or so, largely in response to the ridiculousness of Thabo Mbeki’s pronouncements on the virus and the disease: thanks to tectonic shifts in the UCT Web policy, these disappeared – but thanks to the invaluable Wayback Machine, can still be found.  If you want a slice of history, and to see how bad I am at designing web pages, go take a look. Still MOSTLY valid, although many of the links are now dead – sic transit the web content, unfortunately!

And here we are in 2016: I’m now an elderly academic, the Honours student who alerted me to the fact the the “GRIDS” syndrome virus may have been identified in 1983 is now a senior Professor and distinguished HIV researcher – there’s a whole career there, Carolyn! – and HIV/AIDS is still with us. And unfortunately, Thabo Mbeki is still being wilfully if not malevolently ignorant, and I am still feeling it necessary to crap on him.

At least the pandemic appears to have peaked in terms of incidence, and ARVs are increasingly good and employed widely; however, we still don’t have a decent vaccine, and people are still being infected. This pandemic will last out my career – but hopefully not those of some of the people I have trained.

Posted in biotechnology, Evolution, General Virology, history, HIV, Teaching, Vaccines: General, Viruses | Leave a Comment »

New Approaches to Vaccines for Human and Veterinary Tropical Diseases. Or maybe sophisticated safari science?

27 May, 2016

The Keystone Symposia organisation held a meeting entitled “New Approaches to Vaccines for Human and Veterinary Tropical Diseases” in Cape Town this week (May 22-26, 2016).  A summary of the meeting was given as:

“Human and livestock vaccines can contribute to improved human welfare and income generation by maintaining human health and meeting the demand for meat, milk and fish in developing countries. All of these factors contribute to the growing importance of improving food safety, availability and nutritional security. An important component of this Keystone Symposia meeting will be to stimulate crosstalk between the human and veterinary vaccine communities by highlighting cross-cutting technical advances and new science and knowledge from laboratory and field research. The meeting will also provide a rare opportunity for scientists from the Northern and Southern hemispheres to interact and pool resources and knowledge in the common fight against tropical diseases.”

It succeeded admirably in a couple of these goals: there were delegates there from 31 African countries, as well as many Europeans, Brits and Americans; the juxtaposition of veterinary and medical talks on similar themes created an excited buzz among folk who hadn’t been exposed to the “other”; there was a wealth of dazzling new tech on display in talks, and intriguing insights into how similar – and sometimes, how different – human and animal responses to vaccines were.  It was obvious that approaches used to develop malaria vaccines could benefit animal vaccinology, and indeed, Vish Nene and colleagues from ILRI in Kenya are following some of the same approaches in their work with the East Coast fever disease organism in cattle.

But, there were a couple of buts.  An important one for me was that while there were many Africans there, they were not much exposed in talks, apart from several South Africans. While amazing results were displayed from deep sequencing of antibody gene repertoires of humans and animals and how these developed with affinity maturation; while grand predictions were made as to how bioinformatics and molecular design would revolutionise vaccinology – this was more of the same kind of thing we have got used to in HIV vaccine meetings over nearly twenty years, where Big Science is always going to provide a solution, but never quite gets to it. Why was there no mention of ZMapp antibody therapy for Ebola, when this (OK, I’m biased) was the single most exciting thing to come out of the Ebola outbreak and the international response to it?

I hate to be cynical, but seriously: is there one single vaccine in advanced human trial right now that is a result of intelligent molecular design? Has ANYTHING that has been designed from crystallographic evidence or from cryoEM data actually proven useful in animals or people?  Has dissection of the anti-HIV antibody response development actually, really, taught us anything useful about how we should develop vaccines? Even if South Africans were involved?

I told you I was cynical – and my cynicism was reinforced by a couple of displays of “My Ebola vaccine is better than YOUR Ebola vaccine!”, by folk who shall remain nameless – when it was obvious that both ChAdOx and rVSV vaccines have their merits.

Mind you, the tale of how Ebola vaccines were deployed so rapidly, and how what could have been a 15+ year saga was compressed to less than a year for the rVSV-ZEBOV and ChAdOx vaccines was truly inspirational. It is indeed an object lesson in how to respond to an emerging disease that big companies and philanthropic organisations were able to make many thousand doses of different vaccine candidates in just a few months, and that these could be deployed in human “trials” – actually, genuine deployment in ring vaccination for the VSV candidate – almost immediately.  Adrian Hill of Oxford asked the question, albeit outside the meeting at a seminar in our Institute: if this was possible for an Ebola outbreak, why isn’t it possible for everything else?  Why can’t we do it for Zika virus, and for MERS-CoV too?

If there is a Big Lesson to come out of this meeting, why can’t it be – Let’s Make Vaccines Faster!

Oh, there were big plusses too.  There were fascinating parallels to be drawn in the approaches to developing vaccines for malaria and TB and animal parasitic infections; some of the fancier techniques discussed for human vaccines could obviously find applications in veterinary vaccinology; there were even suggestions for vaccine candidates for animals that were drawn from homologous genes in human and animal apicomplexans (=malaria-like organisms).

I was especially impressed by Dean Everett‘s talk, from the Malawi-Liverpool-Wellcome Trust Clinical Research Programme in Malawi, on “Developing Appropriate Vaccines through Bioinformatics in Africa”: they were actually working in under-developed Africa, on pressing local problems, and making significant inroads into the problems.

And yet, and yet: I have railed elsewhere about the J Craig Venter Institute’s grandstanding over their “synthetic” organisms; while the talk here by Sanjay Vashee on “Synthetic Bacterial and Viral Backbones as Antigen Delivery Vehicle” went some way to redeeming my negative impression of the use of this sort of work, I am still left with the impression that there are considerably easier ways of doing what they claim to be able to. Mind you, one of my colleagues was very impressed with the possibility of making Herpesmids (=infectious, engineerable whole genome clones) in yeast, and would love to do it with their poxvirus collection – so maybe I am a touch TOO too cynical.

I also felt that the final address, by Chris Wilson of the Bill & Melinda Gates Foundation, on: “Cross-Disciplinary Science to Accelerate the Discovery of Vaccines for Global, Zoonotic and Emerging Infectious Diseases” exemplified some of the problems inherent in trying to marry up developed and developing world science, especially in vaccinology.  Part of the talk was great: he gave the best description I’ve yet heard of why it could be feasible to inoculate Aedes spp. with Wolbachia, and why it could significantly impact transmission of flavi- and other viruses.  His description of gene drive technology for wiping out selected mosquito populations was also succinct, and masterly – and appropriate for a developing world audience. Then he got on to how dissection of antibody maturation pathways and flavivirus E protein design could provide paths to good vaccines, and the cynicism kicked in again.

We don’t need either technology to get to vaccines for HIV or for flaviviruses that we can test in the near future, and which could have very significant impacts on millions of people.

Really: we don’t. Extant HIV vaccine candidates are almost certainly better than the RV144 Thai trial vaccine components, and they had an efficacy of 60% in the first year. We already have YFV and dengue and JEV live vaccines – why don’t we use one or several of them in combination with an engineered YFV vaccine to protect against ALL epidemic flaviviruses?  Given the Ebola example, we could deploy vaccines for HIV and for flaviviruses in a year or less, and they would have an impact that would tide us over while fancier products were being made. Seriously: we are always waiting for the next best thing; let’s just apply what we know and what we have NOW to make an impact – instead of, like theoretical physicists, perpetually considering the problem of the spherical horse instead of just going out and riding one.

And that should have been one of the Big Lessons, and we missed it. Instead, there was an element of Safari Science, which is what we in Africa call the kind of endeavour which involves people from the global North flying in to sort out our problems – and leaving with our organisms and disease samples.

Which we could do ourselves, given funding. And that’s another lesson for the folk that do Big Science funding….

 

Posted in biotechnology, Ebola, Ebola, GMOs, HIV, HPV, Influenza viruses, techniques, Vaccines: General | Leave a Comment »

Your next DNA vaccine might come from tobacco

12 February, 2016

We don’t have much practice at this sort of thing, but seeing as we just got something REALLY cool published, and the man who largely made it possible is now a science writer, we decided to ask him to write a press release.  So he did.  Thanks, Paul Kennedy – take a bow, twice!

“In a pioneering step towards using plants to produce vaccines against cervical cancer and other viruses, University of Cape Town (UCT) researchers have generated synthetic human papillomavirus- derived viral particles called pseudovirions in tobacco plants.

“We’ve succeeded in making a completely mammalian viral particle in a plant – proteins, DNA, everything. That’s enormously exciting,” says Dr Inga Hitzeroth of the Biopharming Research Unit (BRU) at UCT.Dr_Inga_Hitzeroth

In an Open Access study just published in Nature Scientific Reports, BRU researchers report using tobacco plants to create a synthetic viral particle known as a pseudovirion.

A pseudovirion looks like a virus, but it contains no infectious viral DNA. A virus is usually made up of a shell surrounding the virus’s own genetic material. Pseudovirions instead carry whatever DNA the researcher wishes to include within the shell of proteins that make up the outer coating of the virus.

Until now, such particles have only ever been created in yeast or mammalian cell cultures – this is the first time researchers have successfully created pseudovirions in plants.

The BRU is part of a new movement known as biopharming, which means using plants as biological factories. Biopharming has been used to create flu vaccines, potential Ebola drugs, and an enzyme used to treat Gaucher’s Disease in humans. The technique employs the cellular machinery within tobacco plants or other plant cells to manufacture enzymes, antibodies or even the viral capsid proteins (the proteins that make up the shell of a virus), which act as vaccines.

In this research, the BRU has taken biopharming one step further by using plants to create a viral shell that encloses ‘custom’ DNA selected by researchers. “What’s unique here is that DNA that was manufactured within the tobacco plant is now being incorporated into a viral particle to form a pseudovirion,” says Hitzeroth.

The shell of this pseudovirion was that of human papillomavirus (HPV) type 16, the virus responsible for over 50% of cervical cancer cases worldwide.

The BRU team hope this new plant-based technology could one day be used to test future HPV vaccines. First author of the study, Dr Renate Lamprecht, renateexplains: “We need pseudovirions to test any new HPV vaccine candidates. At the moment it is very expensive to make pseudovirions – we need to make them in mammalian cell culture, it needs to be sterile, and the reagents are very expensive.”

All these factors contribute to the high cost of current HPV vaccines, which are actually virus-like particles. Virus-like particles (VLPs) are similar to pseudovirions, but they contain no DNA. Plant- made pseudovirions, as demonstrated by this study, could reduce the cost of testing and manufacturing such vaccines, thus helping to make HPV vaccines affordable where they are needed most: the developing world.

PsVs

Plant-made HPV pseudovirions containing geminivirus-derived DNA

The BRU team compared these new plant-made pseudovirions against the more widely-used mammalian cell culture-produced particles by using what’s known as a neutralisation assay. In this test (which is commonly used to test new HPV vaccine candidates), cells are ‘infected’ with pseudovirions, with or without pre-treatment with neutralising antibodies. The DNA inside the pseudovirion carries a ‘reporter gene’ that produces a protein that can give off a light signal. Thus, an infectious pseudovirion gets into the cell and gives off light, but one that is stopped by neutralising antibodies does not.

“I was jumping up and down the first time I saw the neutralisation results, but I repeated the experiment a few times to be sure, asking myself, ‘is everything correct, are all the controls there?’” explains Lamprecht. “It was a very exciting moment for us when we confirmed that neutralisation had occurred.”

Right now, every laboratory makes pseudovirions for such neutralisation experiments themselves. Dr Hitzeroth hopes that one day, they won’t have to: “we’re in the initial stages, but if we optimise the process and get the yield much higher, we think it’s a product that could be sold all over the world.”

ed ebola

Ed’s Ebola shirt

For Professor Ed Rybicki, Director of the BRU, this achievement was enormously satisfying, as it brought together two strands of his research interests that have co-existed for over 20 years.

“Seventeen years ago, I had the idea to combine making HPV VLPs in plants with a DNA plant virus we were working on, to see if we could make pseudovirions. It took until now for the technology to finally come together, but it shows what can happen in biotechnology if you’re willing to persevere.”

The BRU are also hoping to use this technology to create a therapeutic vaccine, which would also be a first of its kind. The idea would be to use the pseudovirion to deliver DNA that could treat an ongoing HPV infection or even a tumour.

With global acceptance and support for the biopharming movement growing rapidly, it might not be too long before the first plant-produced HPV vaccine is making a difference in Africa and around the world.”

For further enquiries, contact Dr Hitzeroth. For more info on biopharming, check out this Q&A session from Sense About Science.

Posted in biofarming, biotechnology, geminivirus, General Virology, GMOs, HPV, techniques, Vaccines: General | 1 Comment »

“Online ‘recipes’ for bird flu virus add to bioterrorism threat!” No. No, they don’t.

10 December, 2015

The means of engineering potentially deadly avian influenza is freely available on the internet.

Despite continuing global efforts to contain avian influenza, or bird flu, the means of engineering this potentially deadly H5N1 virus to render it transmissible to humans is freely available on the internet. So too are similar instructions for engineering a virus like the “Spanish flu”, which killed some 50 million people in the pandemic of 1918-19.

The digital floodgates opened in 2011 when a peak US regulatory watchdog came down in favour of scientists seeking to publishing their work engineering the H5N1 virus. The decision to uphold such “scientific freedom” was and remains, highly contentious among the global scientific community. Its implications, however, are readily available as online “recipes” for potentially dangerous viruses, which add a new risk to the already considerable challenges of maintaining global biosecurity in the 21st century. For all the recent advances in biomedical science, drugs, vaccines and technology, this is a challenge we remain ill-equipped to meet.

Read more: http://www.theage.com.au/comment/online-recipes-for-contagious-diseases-means-australias-bioterrorism-threat-is-real-20151208-gli97v.html#ixzz3tvWn63AE ;
Follow us: @theage on Twitter | theageAustralia on Facebook

Sourced through Scoop.it from: www.theage.com.au

 

OFFS: seriously!  Again?!  Someone else has just discovered that entire virus genomes are freely available via PubMed, along with papers on gain-of-function experiments, and immediately leaps to the conclusion that this means “…the means of engineering this potentially deadly H5N1 virus to render it transmissible to humans is freely available on the internet”.

I’m sorry, this is being simple-minded to the point of parody.  I have written elsewhere – here in ViroBlogy, and in Nature Biotech’s Bioentrepreneur blog section – on how it is MOST unlikely that bearded fellows in caves in Afghanistan or remote farms in Montana are going to whip up weaponised batches of H5N1 flu or Ebola.

Yes, the papers are available; yes, the sequences necessary to make a potentially (and I say potentially advisedly) deadly virus are available online; yes, one can bypass the blocks on getting resynthesised genes in developing countries (hint: China).

But could anyone outside of a sophisticated lab environment use these to make anything nasty?

No.

Seriously, no.

Just think about what you would need to make weaponised flu, for example.  There are two ways to go here, these being the totally synthetic route (“mail order” DNA – HATE that term!), with some serious molecular biology and cell culture at the end of it, and the “natural” route – which would involve getting a natural and nasty isolate of H5N1 / H7N9 / H9N2, and being able to culture it and engineer it as well.

Both routes require a minimum of a serious 4-yr-degree-level training in microbiology / mol biol, as well as laboratory resources that would include incubators, biohazard cabinets, and disposables and reagents that are not on your normal terrorist’s priority purchase list.

In fact, the kinds of resources you’d find at a University or Institute Infectious Disease unit – or state-sponsored biowarfare lab.

Seriously, now: in order to use the information that is “freely available”, you’d have to do what amounts to an entire postgrad degree’s worth of work just to set up the kinds of reverse genetics necessary to WORK with recombinant flu, presuming you already had an isolate, and even more than that if you were to start with synthesised DNA and try to recreate infectious virus.

Again, this is the kind of work they do in biowarfare / biodefence labs (funny how they’re pretty much the same thing, isn’t it?) – because it’s finicky, expensive, laborious – and potentially dangerous to the researcher.

And it’s interesting that the only rumoured escapes of biowarfare agents have been of flu in 1977 in the old Soviet Union, and of anthrax in Sverdlovsk in the USSR in 1979. And in the US in 2001, and again in 2014.  ALL of them from official facilities, I will discreetly point out.

Oh, there have been rumours that Saddam’s Iraq weaponised camelpox; that the USSR/Russia cloned Ebola into a poxvirus; that Al-Qaeda tested anthrax – but the first two took state resources, and if the third happened at all, it’s nothing that the UK and USA and friends hadn’t already done in the 1940s.

IT IS NOT THAT EASY TO MAKE RECOMBINANT VIRUSES.

Seriously.

See on Scoop.it – Virology News

Posted in biofarming, biotechnology, Ebola, Evolution, General Virology, GMOs, history, Influenza viruses, techniques, Vaccines: General, Viruses | 1 Comment »

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