No Adverse Events Reported So Far With H1N1 Influenza Vaccine

2009 H1N1: What's New This Week -- Commentary by John G. Bartlett, MD

No adverse events have been reported as yet from the H1N1 influenza vaccine, according to experts who are tracking the vaccine's safety through several postmarketing surveillance programs. Experts caution, however, that the 2009 H1N1 influenza vaccines have only recently begun to be administered, and the data are insufficient to assess safety of the vaccine.
Commentary
The experience so far is with careful analysis of adverse events with 10 million doses of the 2009 influenza A (H1N1) vaccine already administered in the United States. The director of the program, Bruce Gellin, MD, MPH, claims that in regard to safety, there are "no signals yet." A major concern is the "background noise" -- adverse events that would happen anyway, but are implicated because they are temporally tied to the vaccine. For example, within 6 weeks of vaccination there will be:
22 cases of Guillain-Barré syndrome/10 million vaccinations;
16,684 spontaneous abortions/1 million vaccinated pregnant women; and
6 sudden deaths/10 million vaccinations.[3]
The voluntary Vaccine Adverse Reporting System (VAERS) has summarized results through November 2, 2009 on the basis of reports after 33.7 million doses were administered. This showed 84 reactions considered serious, including 6 deaths that are currently under review and 4 cases of Guillain-Barré syndrome. All of these are currently under investigation, but the numbers are not striking and the analysis so far is not showing any concern