Friday, June 12, 2009

Now that we're in a Swine Flu pandemic, what about vaccines?

-Crystal Zheng
This is in response to: “Drugmakers rush to produce a swine flu vaccine” Associated Press

With yesterday’s raise of the pandemic flu level to phase six, signaling the start of the first flu pandemic since 1968, a natural question that arises is that of vaccines. As of right now, there is no vaccine for swine flu, and seasonal flu does not seem to provide immunity (although no studies have been done to this effect). Prior to yesterday’s announcement, the WHO website indicated that a swine flu vaccine could be ready within six months. However, now that we are officially in a pandemic, vaccine companies have pushed up that deadline, with many including GlaxoSmithKline and Sanofi-Aventis announcing that they would be ready to mass produce a vaccine for swine flu within weeks. The traditional flu vaccine is made in chicken eggs, but Novartis has developed a swine-flu vaccine that uses a cellular method, which may be faster. However, this new technology will not contribute significantly to our vaccine stocks, since the majority of vaccines will still be made using chicken eggs. The WHO estimates 2.4 billion doses of swine flu vaccine could be ready within a year.
Still, I have a lot of questions: first, who will get access to those vaccines? How will we prioritize vaccination? Will we vaccinate everybody, or promote vaccination for only at risk populations? Most of the developed countries began preparing for a pandemic long ago by signing contracts with vaccine companies to acquire sufficient supply for its populations. Many less developed countries will not have access to vaccine, not only because of cost but also due to politics. The WHO has asked vaccine companies to reserve a portion of their supply for poor countries. While some companies have helped, for example GlaxoSmithKine has donated 50m doses of vaccine, in practice, vaccines generally don’t leave the country of production until everyone in its home country is vaccinated, regardless of promises.
The lack of vaccines in developing countries is particularly disconcerting because these countries are more vulnerable during a pandemic. Their populations have higher incidences of underlying conditions, such as chronic disease and malnutrition; development lags behind, making them more susceptible to secondary infections; the population is younger and more densely packed in urban areas, facilitating spread; finally, health systems are not adequate to treat the large influx of patients that would seek treatment in the case of a pandemic. While it could be considered fortunate that so far swine flu has been contained to the more developed countries, its spread to less developed countries may not be far away.
Another challenge is to balance production of swine flu vaccine with seasonal flu vaccine. The production capacity of vaccine companies is limited, and resources shifted to swine flu vaccine will have to trade off with seasonal flu. What is the right balance to strike, considering that swine flu so far has generally caused mild symptoms and has a smaller mortality rate than seasonal flu, which will continue to kill tens of thousands.
In my opinion, we cannot allow swine flu to let us forget completely about seasonal flu. To this end, we must promote and prioritize strategies that would have benefits for both swine and seasonal flu, such as improving access to antivirals and antibacterials that can be used as treatment options for both flus, promoting basic health behaviors and knowledge at the individual level, and capacity building, such as training emergency health technicians.

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