Archive for May, 2012

Landes Bioscience Journals: Human Vaccines & Immunotherapeutics

7 May, 2012

See on Scoop.itVirology News

Rapid production of influenza vaccine antigen is an important challenge when a new pandemic occurs. Production of recombinant antigens in plants is a quick, cost effective and up scalable new strategy for influenza vaccine production.  In this study, we have characterized a recombinant influenza haemagglutinin antigen (HAC1) that was derived from the 2009 pandemic H1N1 virus and expressed in tobacco plants. Volunteers vaccinated with the 2009 pH1N1 oil-in-water adjuvanted vaccine provided serum and lymphocyte samples that were used to study the immunogenic properties of the HAC1 antigen in vitro. By 7 d post vaccination, the vaccine fulfilled the licensing criteria for antibody responses to the HA detected by haemagglutination inhibition and single radial hemolysis. By ELISA and ELISPOT analysis we showed that HAC1 was recognized by specific serum antibodies and antibody secreting cells, respectively. We conducted a kinetic analysis and found a peak of serum HAC1 spec antibody response between day 14 and 21 post vaccination by ELISA. We also detected elevated production of IL-2 and IFNγ and low frequencies of CD4+ T cells producing single or multiple Th1 cytokines after stimulating PBMCs (peripheral blood mononuclear cells) with the HAC1 antigen in vitro. This indicates that the antigen can interact with T cells, although confirming an effective adjuvant would be required to improve the T-cell stimulation of plant based vaccines. We conclude that the tobacco derived recombinant HAC1 antigen is a promising vaccine candidate recognized by both B- and T cells.


Fraunhofer USA, waving the Green Vaccine flag: way to go….

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Setting up a platform for plant-based influenza virus vaccine production in South Africa

5 May, 2012

A virus-like particle formed by influenza virus haemagglutinin budding out of plant cells. By Russell Kightley Media

See it also on Scoop.itVirology News

Our (very) recently-published article on plant-made flu vaccines in BMC Biotechnology:

Setting up a platform for plant-based influenza virus vaccine production in South Africa

Elizabeth Mortimer, James M Maclean, Sandiswa Mbewana, Amelia Buys, Anna-Lise Williamson, Inga I Hitzeroth and Edward P Rybicki

During a global influenza pandemic, the vaccine requirements of developing countries can surpass their supply capabilities, if these exist at all, compelling them to rely on developed countries for stocks that may not be available in time. There is thus a need for developing countries in general to produce their own pandemic and possibly seasonal influenza vaccines. Here we describe the development of a plant-based platform for producing influenza vaccines locally, in South Africa. Plant-produced influenza vaccine candidates are quicker to develop and potentially cheaper than egg-produced influenza vaccines, and their production can be rapidly upscaled. In this study, we investigated the feasibility of producing a vaccine to the highly pathogenic avian influenza A subtype H5N1 virus, the most generally virulent influenza virus identified to date. Two variants of the haemagglutinin (HA) surface glycoprotein gene were synthesised for optimum expression in plants: these were the full-length HA gene (H5) and a truncated form lacking the transmembrane domain (H5tr). The genes were cloned into a panel of Agrobacterium tumefaciens binary plant expression vectors in order to test HA accumulation in different cell compartments. The constructs were transiently expressed in tobacco by means of agroinfiltration. Stable transgenic tobacco plants were also generated to provide seed for stable storage of the material as a pre-pandemic strategy.

For both transient and transgenic expression systems the highest accumulation of full-length H5 protein occurred in the apoplastic spaces, while the highest accumulation of H5tr was in the endoplasmic reticulum. The H5 proteins were produced at relatively high concentrations in both systems. Following partial purification, haemagglutination and haemagglutination inhibition tests indicated that the conformation of the plant-produced HA variants was correct and the proteins were functional. The immunisation of chickens and mice with the candidate vaccines elicited HA-specific antibody responses.

We managed, after synthesis of two versions of a single gene, to produce by transient and transgenic expression in plants, two variants of a highly pathogenic avian influenza virus HA protein which could have vaccine potential. This is a proof of principle of the potential of plant-produced influenza vaccines as a feasible pandemic response strategy for South Africa and other developing countries.”

I have mentioned time and again that going green is the sensible thing to do: here is a concrete example of how my research group is trying to go about it.  This is a very sensible technology for rapid-response vaccine production, and especially for emerging or orphan or pandemic virus threats.  We got really good expresion levels of H5N1 HA protein via transient expression in plants, and have already started on pandemic H1N1 HA expression.  Let’s hope some governmental types in SA take some notice!

I thank Russell Kightley Media for the specially-commissioned graphic of budded HA-only VLPs.


HIV/AIDS: New book tracks the epidemic to its origins

4 May, 2012

See on Scoop.itVirology News

We’ve all heard the myths and hypotheses about the origins of the epidemic caused by the HI virus, but a new book, “Tinderbox: How the West Sparked the AIDS Epidemic and How the World Can Finally Overcome It”, sheds more light on where it all began.


I’ve covered this before, but it’s a nice review – complete with spoilers like how Beatrice Hahn and team have shown that a chimpanzee SIV from Cameroon is the closest relative of HIV-1 group M viruses.  The gun doesn’t smoke more than that.

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Religious sites ‘riskier than porn for viruses’ – Ninemsn

4 May, 2012

See on Scoop.itVirology News

CIO TodayReligious sites ‘riskier than porn for viruses’NinemsnWeb wanderers are more likely to get a computer virus by visiting a religious website than by peering at porn, according to a study released on Tuesday.


I love it: Dawkins was right!  Religion IS a virus….

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Flu research: How to make bird flu transmissible…

4 May, 2012

See on Scoop.itVirology News

“On April 27th, after much toing and froing, the Dutch government gave Ron Fouchier of the Erasmus Medical Centre in Rotterdam permission to submit his paper on bird flu to Science.”


And so it FINALLY comes to pass – two papers that SHOULD have been published weeks ago, finally see the light.

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Mutant flu paper is finally published, reveals pandemic potential of wild viruses | Not Exactly Rocket Science | Discover Magazine

3 May, 2012

See on Scoop.itVirology News

“It’s finally out. After months of will-they-won’t they and should-they-shouldn’t-they deliberations, Nature has finally published a paper about a mutant strain of bird flu that can spread between mammals.”


This is the Kawaoka paper, which in fact was the LESS contentious one.  Ed Yong in Discover magazine comes up with four important themes from the paper, which to my mind show we were right to agitate and demand that the material be published.


One: H5N1 can evolve to spread between mammals with worrying ease

Two: There appear to be two traits that make for a transmissible virus – specificity and stability.

Three: It’s not the mutations that matter, but what they do. Or, don’t miss the wood for the trees.

Four: Wild viruses are almost there.


One and four are the important points: flu viruses can evolve quickly and easily, and wild H5N1 is nearly at the point that it will leap into mammals.  The virus is endemic in several countries, like Indonesia, where wild birds, tame birds, pigs and people rub shoulders on a daily basis: this is a natural melting pot for influenza virus reassortment and adaptation, that may at any moment see a pandemic virus burst out.

Or not – it may as easily be a H7NX virus that will be The Big One.

But it is as well to be prepared – and censorship wasn’t going to allow that.

Thanks @AJCann for alerting me to this.

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