“There are H5 vaccines out there, and there are some stockpiled in some high-income countries,” said Dr Nicole Lurie, executive director for preparedness and response at the Coalition for Epidemic Preparedness Innovations (Cepi).
“[But] a lot of things have been frozen for a pretty long time now and are quite old. I think we all hope that they will be fine, but we don’t necessarily know.”
Even the optimists point out that even if the stockpiled vaccines do work, existing supplies would barely be enough to cover healthcare workers.
Dr Richard Webby, director of the World Health Organization (WHO) Collaborating Centre for Studies on the Ecology of Influenza in the US, said we were better prepared for H5N1 than other viruses but said it would take a while to gear up.
“Are we going to have enough vaccine to meet demands in the first few weeks of such an outbreak? The answer to that is clearly no,” he said.
There is also the important question of whether the vaccines we have today are a good match for the new strains of H5N1 circulating.
The limited data available is not convincing. Only two of the four vaccines currently stockpiled are thought to be a good match for the current H5N1 stain, and even they may not work especially well.
Former FDA official Dr Luciana Borio told the World Vaccine Congress in Washington last month that the efficacy is potentially as low as 45 per cent, based on studies looking at antibody responses.
A similar problem happened when H1N1 swine flu broke out in 2008/9. Although vaccine stockpiles covered the strain circulating, a study later found it protected young people but had no discernible impact on older adults.
In other words: there’s no guarantee a shot would live up to expectations – or arrive in time.
With swine flu, the vaccine rollout began in earnest only after the most significant wave of infections had peaked. Thankfully, the virus turned out to be very mild.
