# 4119
The safety data from the first six weeks of H1N1 vaccinations has been reassuringly good, with no early `red flags’ such as we saw back in 1976. Most of the side effects have been mild, and the number of severe side effects has been about what we would expect from the seasonal vaccine.
Obviously public health officials are starting to heave a sigh of relief. Not that they expected a different outcome, but anytime you release a vaccine there is always the potential for seeing increased side effects.
While ongoing monitoring will be needed, and problems could still present in the weeks ahead, right now the news is very encouraging.
Today the MMWR (Morbidity and Mortality Weekly Report) has a summary of adverse events associated with the pandemic and seasonal vaccines.
A few excerpts (reparagraphed) below, but follow the link to read it in its entirety.
Safety of Influenza A (H1N1) 2009 Monovalent Vaccines --- United States, October 1--November 24, 2009
Through November 24, VAERS received 3,783 reports of adverse events after receipt of H1N1 vaccine, of which 204 were categorized as serious, and 4,672 reports after receipt of seasonal influenza vaccines, of which 283 were serious.
During October 5--November 20, a total of 46.2 million doses of H1N1 vaccines (11.3 million LAMV and 34.9 million MIV doses) and 98.9 million doses of seasonal influenza vaccines were distributed to U.S states and territories.
The overall VAERS adverse event reporting rates were 82 per 1 million H1N1 vaccine doses distributed and 47 per 1 million seasonal influenza vaccine doses distributed.
The serious adverse event reporting rates were 4.4 and 2.9 serious adverse events per 1 million doses distributed for H1N1 vaccines and seasonal influenza vaccines, respectively.
However, the percentage of serious adverse events among all adverse events reported after receipt of seasonal influenza vaccines was slightly higher (6.1%), compared with the percentage of serious adverse events after receipt of H1N1 vaccines (5.4%), and this finding was consistent for inactivated (5.8% versus 5.5%) and live attenuated (7.3% versus 4.7%) vaccines (Table 1).
