MARSHFIELD, Wis., Jan. 11, 2013 /PRNewswire/ -- Influenza has hit the U.S. hard this winter, but early estimates show the vaccine significantly reduces the risk of getting the flu, according to a national report released today.
The vaccine, which protects against two influenza A and one influenza B virus strains, is 62 percent effective so far this season, according to a report from the U.S. Flu Vaccine Effectiveness Network, which includes the Marshfield Clinic Research Foundation in Marshfield, Wis. The Centers for Disease Control and Prevention (CDC) supports the network.
"The take home message is that the flu vaccine is moderately effective this year, and people who are vaccinated have about a 60 percent lower risk of getting the flu compared to someone who is not vaccinated. It's a safe vaccine that can help prevent the flu and its complications in both children and adults," said Dr. Edward Belongia, an epidemiologist and a lead researcher on the report. He also serves as director of the Epidemiology Research Center at the Marshfield Clinic Research Foundation.
The effectiveness of the flu vaccine can vary from year to year due to changes in the flu viruses and vaccine components.The estimated effectiveness against influenza A was 55 percent and against influenza B it was 70 percent effective, the report said. The final effectiveness estimates may vary from the early-season report. The early vaccine effectiveness in 2013 is similar to the level of effectiveness reported in other recent flu seasons, and in clinical trials of flu vaccines. The rate of influenza cases began to increase rapidly in December, marking the flu season's earliest start in a decade, according to the CDC. The predominant type of flu circulating in the U.S. is H3N2 influenza A virus, according to the report. Seasons dominated by the H3N2 strain tend to be more severe, with a greater number of hospitalizations and deaths, Belongia said.