Friday, January 06, 2012

H3N2v Vaccine Trials



Photo Credit PHIL

# 6055



In a bit of a follow up to yesterday’s blog (see H3N2v: Three’s A Crowd) - where we looked at the impact that a newly emerging influenza A virus might have on next fall’s flu vaccination program - we’ve a report from Medscape News (free registration req.) on the development of a vaccine for the novel H3N2v virus.



Trials for Novel Influenza Vaccine Likely by Spring

Robert Lowes

January 5, 2012 — A precautionary vaccine against the novel swine influenza virus, which has sickened 12 people in 5 states since July, is in development and will likely be ready for clinical trials this spring, a spokesperson for the Department of Health and Human Services (HHS) told Medscape Medical News.

(Continue . . . )



Early in December we learned from CIDRAP NEWS that the CDC was working on a `seed vaccine’ against this emerging strain, based on an older H3N2 swine flu virus collected from Minnesota in 2010 (see Vaccine virus for novel H3N2 based on 2010 swine flu strain).


At that time scientists were running into some problems getting the new H3N2v virus to grow well in eggs, a crucial first step in the process of creating a high-yield reassortant virus.


A high-yield reassortant is a laboratory-created hybrid that contains the surface genes of the target virus – which provides its antigenic qualities - combined with the internal genes of a virus already known to grow rapidly and dependably in eggs.


You may recall that in the summer of  2009 there were early problems in the production of the H1N1 pandemic vaccine (see Vaccine Yields Continue To Disappoint). 


Working out the development and manufacturing kinks now, before a novel virus can pose an imminent threat, is only prudent.  It can save weeks, or even months, in the rolling out of a vaccine in the event of a pandemic.


Candidate vaccines have been developed for a number of novel flu strains in recent years, including several clades of the H5N1 virus, H7N5, and last September we learned that Bangladesh had sent an H9N2 virus to the CDC for development of a seed vaccine.


It’s not completely clear from this Medscape article whether this investigational vaccine will be based on the 2010 Minnesota H3N2 virus, or if they’ve managed to turn one of the newer H3N2v isolates into a high yield reassortant.


Hopefully we’ll get more details in the near future. 

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