Initial data on swine flu adverse event reporting/ MMWR

Per CDC's MMWR, as of November 24, VAERS data indicated 82 adverse event reports per 1 million H1N1 vaccine doses distributed, compared with 47 reports per 1 million seasonal influenza vaccine doses distributed.

Adverse events designated serious were 50% higher (based on doses distributed, not doses used) for swine flu compared to seasonal flu. Monitoring will continue over a longer duration and for more vaccine doses. For 13 deaths reported following vaccination:

"No patterns in age, sex, or type of underlying medical condition were observed that might lead investigators to suspect a causal link with vaccination."