Does administering the seasonal flu vaccine increase a patients chances of infection with the 2009 H1N1 influenza virus?
The CDC has reviewed data from studies done in the United States and Australia and found that receipt of seasonal influenza vaccine neither increased nor decreased the risk of getting 2009 H1N1 influenza. In contrast, a small published study from Mexico found that seasonal vaccine provided some protection against 2009 H1N1 influenza. There has been recent media coverage about research conducted in Canada that suggests getting a seasonal flu vaccination increases a person’s chances for becoming infected with the 2009 H1N1 influenza virus. No other country has reported that seasonal vaccine has any positive or negative effect on the risk of becoming infected with 2009 H1N1 influenza.
