As the nation prepares for the return of the H1N1 influenza pandemic, public health officials are faced with difficult choices. While some doses of the vaccine for what is known as "swine flu" will be ready by October, the entire supply will not be available for several more months.
Recently, two landmark meetings have been convened to discuss plans for the evaluation and use of vaccines against H1N1. On July 23rd, the Vaccine and Related Biological Products Advisory Committee (VRBPAC) of the FDA met to discuss ongoing vaccine trials and pathways for licensure or emergency use authorization of a variety of vaccines. On July 29th, the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control met to determine who should receive vaccine first.
A single number has dominated these discussions: 600 million. That's the number of doses that would allow every American to be immunized twice (since this is a new virus, it is possible that everyone will need two doses of vaccine to achieve protection). Debate and discussion have centered over the fastest and safest way to get to this number: whether, for example, some inactivated (killed) vaccines used in the U.S. could contain dose-sparing additives called adjuvants that might be used to stretch the supply of inactivated vaccine to get to 600 million more quickly, or how to best package a live attenuated vaccine, normally dispensed by nasal spray if, as appears likely, there will be more doses of this vaccine available than spray devices to administer them.
But is 600 million the right number? That the United States should aim to produce enough vaccine to protect all Americans is not at issue. What is not being addressed, however, is whether we ought to aim to do more. Nowhere in these discussions has the prospect of upping the ante been raised. Should we use available technologies to provide not only enough vaccine for the U.S. but also to allow for excess capacity to assist other countries who have no capacity to procure or produce the vaccine on their own?
The ultimate severity of the H1N1 2009 pandemic cannot be predicted. However, we do know that context matters and that loss of life is likely to be greatest in resource-poor settings. Careful research established that in the 1918 pandemic the death rate in poor countries was as much as thirty-fold higher than the death rate in wealthy countries; it is predicted that up to 96 percent of deaths from a new pandemic may occur in developing countries. When Margaret Chan, the director-general of World Heatlh Organization, declared an influenza pandemic on June 11, she made special mention of the likely increased burden in these countries: "Although the pandemic appears to have moderate severity in comparatively well-off countries, it is prudent to anticipate a bleaker picture as the virus spreads to areas with limited resources, poor health care and a high prevalence of underlying medical problems."
The H1N1 2009 influenza pandemic will be with us for months and possibly years to come. Multiple populations will be affected, and some are at special risk, including pregnant women, young children and those with underlying medical conditions. Vaccination will be our most effective medical countermeasure, and using a number of different types of vaccines: live and killed, with and without adjuvant, would allow us to immunize the U.S. population most efficiently.
But do our obligations to minimize the burden of death and disease from H1N1 end there? If we use the available stocks of vaccine and adjuvant wisely, we may also be able to reach beyond our borders and afford some protection to the world's most vulnerable populations. Global needs, as well as our own, should inform our decisions as we plan the nation's H1N1 vaccine strategy.
Ruth Karron is the Director of the Center for Immunization Research and the Johns Hopkins Vaccine Initiative at the Johns Hopkins Bloomberg School of Public Health. Ruth Faden is the Director of the Johns Hopkins Berman Institute of Bioethics. Their e-mail addresses are email@example.com and firstname.lastname@example.org.