WHO Estimates 65 Million Have Received H1N1 Shots
Around 80 million doses of vaccine for this virus have been distributed worldwide. The agency says there have been few reports of adverse reactions, including fewer than 10 suspected cases of Guillain-Barre syndrome in people who have received vaccine.
Vaccines for H1N1 2009 influenza are working well in worldwide distribution, the World Health Organization said in its latest briefing note on the pandemic. An estimated 65 million people have received H1N1 vaccinations, and about 80 million doses of vaccine for this virus have been distributed. "Given this scale of vaccine administration, at least some rare adverse reactions, not detectable during even large clinical trials, could occur, underscoring the need for rigorous monitoring of safety. Results to date are encouraging," the agency said Nov. 19.
"As anticipated, side effects commonly reported include swelling, redness, or pain at the injection site, which usually resolves spontaneously a short time after vaccination. Fever, headache, fatigue, and muscle aches, occurring shortly after vaccine administration, have also been reported, though with less frequency. These symptoms also resolve spontaneously, usually within 48 hours. In addition, a variety of allergic reactions has been observed. The frequency of these reactions is well within the expected range," WHO notes, adding that fewer than 10 suspected cases of Guillain-Barre syndrome have been reported among people who received vaccine. "These numbers are in line with normal background rates of this illness, as reported in a recent study. Nonetheless, all such cases are being investigated to determine whether these are randomly occurring events or if they might be associated with vaccination. WHO has received no reports of fatal outcomes among suspected or confirmed cases of Guillain-Barre syndrome detected since vaccination campaigns began. All cases have recovered. WHO recommends continued active monitoring for Guillain-Barre syndrome."
FDA announced Monday it had approved a fifth monovalent vaccine for protection against the 2009 H1N1 influenza virus. Like the four vaccines approved Sept. 15, 2009, this vaccine, which is manufactured by GlaxoSmithKline PLC unit ID Biomedical Corp. of Quebec, Canada, uses the same egg-based manufacturing process that produces U.S. seasonal flu vaccines. For information about this and the other four approved vaccines, visit the FDA page on Influenza A (H1N1) 2009 Monovalent Vaccine. "As with any medical product, unexpected or rare serious adverse events may occur," the agency notes, adding it is collaborating with the U.S. Department of Health and Human Services and other government agencies on enhanced adverse event safety monitoring during and after the 2009 H1N1 vaccination program.