Friday, January 05, 2007

Denmark Orders Vaccine

 

# 276

 

We can now add Denmark to the list of countries ordering a pre-pandemic vaccine, according to this news report from the Canadian Press. While details are thus far sketchy, GSK (GlaxoSmithKline) has reportedly agreed to provide 4.6 million doses of their adjuvant enhanced avian flu vaccine to the Danes for an, as yet, undisclosed price.

 

Denmark, with a population in 2006 estimated at roughly 5.4 million, would have enough vaccine to inoculate half of its population with two doses, according to Nils Strandberg Pedersen. director of Denmark's Statens Serum Institut.

 

GSK’s vaccine utilizes a proprietary adjuvant, or immune booster, to increase the effectiveness of their inoculation and reduce the amount of antigen required for each dose.

 

The seasonal flu shot, which most of us are familiar with, requires about 15 micrograms of antigen per shot. Last year, the NIH (National Institute of Health) conducted tests with an early H5N1 vaccine and determined that it would take as much as 180 micrograms, in two shots of 90 micrograms given 30 days apart, to confer immunity.

 

GKS’s adjuvant reportedly elicits an immune response with as little as 3.8 micrograms. Company officials have thus far refused to reveal the identity of this adjuvant.

 

The stockpiling of a pre-pandemic vaccine is becoming a popular option, and in recent weeks we’ve seen Japan, Switzerland and the United States make orders. The UK is reportedly negotiating for a vaccine also.

 

With the exception of Denmark and Switzerland, most countries are only ordering in enough to cover a very small percentage of their population. The United States expects to have roughly 8 million doses, or enough for a little less than 3% of the population.

 

Exactly how well a vaccine will work, when based on an older version of the H5N1 bird flu virus, is unknown. Conventional wisdom, up until a few months ago, said `not very well’. But new studies have come out indicating that even a poorly matched vaccine might confer some immunity.

 

It is hoped that a pre-pandemic vaccine might lessen the morbidity and mortality rates of a pandemic, even if it doesn’t necessarily prevent infection. And there is hope that it would help `prime’ the immune system, making any follow up pandemic-strain specific vaccine more effective.

 

Investing in a pre-pandemic vaccine is risky. It is expensive, it is not guaranteed to be effective, and it has a fairly short shelf life.

 

But given the alternatives, with little else to offer front line workers during a pandemic, it would seem to me to be a risk worth taking.