Flu Vaccine Effectiveness Better than Last Year's

The flu vaccine this year is proving more effective than last year's vaccine, according to federal health officials.

Latest data on this year's influenza season indicates that the flu vaccine is reducing a vaccinated person's risk of contracting influenza by 61 percent, according to the Centers for Disease Control and Prevention (CDC).

The data also indicated that the vaccine is 62 percent effective at preventing a H1N1 influenza virus. So far, it has been estimated that the H1N1 virus from 2009 has made up 98 percent of this season's detected influenza cases. According to the CDC, the frequency of other influenza infections, such as the H3N2 strain, was too minimal to properly measure the effectiveness of the vaccine.

Public health officials say that this year's vaccine is functioning around the effectiveness it was expected to on release. Interestingly, that's still 10 percent higher than last season's vaccine, which only reported an end-season effectiveness of 51 percent.

It should be noted that this current report is only a mid-season report. To calculate total effectiveness of each season's vaccine, the CDC takes two measurements. One measurement is taken halfway through the season, and the other is taken at the end of the season. Interestingly, the mid-season estimate is often lower or equal to the end-season estimate, meaning that the effectiveness of this year's vaccine may even be better than what is currently being reported.

It should also be noted that while influenza is notorious for targeting the elderly, this year's vaccine has been 53 percent effective at preventing infection in people 65 years old and older. According to the CDC, this data is significantly higher than last year's rates for the vaccine which was designed to fight off the then predominant H3N2 virus.

Still, this data might not be all the vaccine's doing along. Previous reports from the CDC have indicated that this year's influenza virus is targeting young and overweight individuals far more than usual. Meanwhile, the elderly seems to have significantly lower hospitalization rates than usual, providing evidence that people over the age of 65 likely have more antibodies to help fight off or prevent a H1N1 infection.

The CDC's mid-season vaccine effectiveness report was released to the public on February 20.