Tuesday, 19 November 2013

H7N9 vaccine progresses through Phase I trials...

Back in August I wrote about Novavax entering Phase I clinical trials with its virus-like particle vaccine (VLP) to prevent influenza A(H7N9) virus disease. It is based on the A/Anhui/1/2013 strain.

Novavax, A United States company, has now reported in the New England Journal of Medicine that 80% of people may be protected by the generation of anti-H7N9 antibodies in response to 2x 5μg injections in the presence of 60 units of CSL's Iscomatrix adjuvant (see more on adjuvants in my August piece). 284 people were enrolled in a trial in Australia to determine these "very preliminary" results. Increased reactions were seen among the immunized at the injection site, but few were severe.

The move away from the egg-based vaccine manufacturing system is likely to allow vaccines to be produced in much shorter periods; 12-weeks after an outbreak starts, with 50,000,000 doses potentially available in 4-months.

You may ask, why then is it precisely 9-months after the 1st H7N9 case was retrospectively identified, and Novavax is still only at Phase I trials? I think, and I'm no expert in this area, that the process will increase in speed once the 'backbone' (the VLPs being used here which are based on a baculovirus, all produced in insect cells) in combination with this adjuvant etc, have been through the entire clinical trial process the first time. A successful backbone can be leveraged for other vaccines too.

You can see a little more of the process of making the VLPs, in this case for respiratory syncytial virus, here.

So, big changes lie not-too-far ahead for influenza vaccines....assuming the course through clicnial trials is smooth sailing of course!

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