When will swine flu vaccine be available?
Here are clarifications to some of the confusion surrounding swine flu: pregnant women appear more susceptible to infection; WHO estimates that by August, global production of the vaccine will reach 94.5 million doses per week; pregnant women and obese people will likely be first to be vaccinated
The confusion about swine flu appears to be spreading almost as fast as the pandemic. What should pregnant women do? Who will be vaccinated, and when? Debora MacKenzie explains.
Pregnancy
The U.S. Centers or Disease Control and Prevention (CDC) found that 8 percent of the first 99 people who died from swine flu in the United States were pregnant, and at the time of writing two of 29 deaths in the United Kingdom are known to have been pregnant or new mothers. About two per cent of women are pregnant at a given time.
Women’s immune reactions are suppressed during pregnancy so they will not attack the genetically foreign fetus. This might explain why pregnant women seem to be slightly more vulnerable to the virus. The United Kingdom has advised advised pregnant women to avoid crowds where possible and unnecessary travel.
When can we expect a vaccine?
It is not clear. The World Health Organization (WHO) estimates that, by August, global production of the vaccine will reach 94.5 million doses per week. This estimate, however, relies on all companies using formulations with novel adjuvants — additives to the vaccine that boost the immune response and reduce the amount of virus needed for each dose.
The adjuvants, however, have not been approved for use in the United States. Last week the U.S. National Biodefense Science Board said that in order to have any vaccine available by September, the United States should stick to the well-tested formulation of the seasonal flu vaccine — with 15 micrograms of the main viral protein, haemagglutinin, per dose.
The WHO warns though that if adjuvants are not “fully used” the amount of vaccine available per week will fall by 40-50 percent.
Who will get the vaccine first?
Again, it is hard to come up with a clear answer. The United States, United Kingdom, and other governments have promised that people at greatest risk from the virus will be vaccinated first. It is not yet known if this means people who are obese or pregnant — so far the clearest risk factors.
