CDC: Flu Vaccine Reduces the Risk of Infection by Nearly Half This Season

A new report from the Centers for Disease Control and Prevention revealed that the flu vaccine this season could reduce the risk of infection by nearly half.

According to CDC's Morbidity and Mortality Weekly Report, the flu vaccine for the 2016-2017 season has an overall protection of 48 percent against influenza A and influenza B virus infection associated with medically attended acute respiratory illness.

For the report, researchers from CDC analyzed the data from 3,144 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness Network (U.S. Flu VE Network) during November 28, 2016 to February 4, 2017. Using these data, the researchers were able to estimate the adjusted effectiveness of the influenza vaccine in preventing influenza virus infection.

The researchers found that the estimated effectiveness of the vaccine against the influenza A (H3N2) strain was 43 percent. On the other hand the effectiveness of the vaccine in preventing influenza B virus was 73 percent. These translate to an estimated overall protection of 48 percent.

"The viruses in the vaccine are a good match for the circulating viruses this season," said Brendan Flannery, lead investigator for the US Flu Vaccine Effectiveness Network, in a report from CNN. "The prediction for the H3N2 virus was right on in terms of that particular virus continuing to be a dominant virus."

The 2016-2017 flu season is becoming a moderately severe. Compared to the past year, the effectiveness of the flu vaccine is relatively high. During the 2014-2015 season, in which the dominant strain is also H3N2, the effectiveness of the vaccine was just 19 percent.

Despite some indications of declining infections the Northwest, there are still certain parts of the country with increasing rates of infection, like the Midwest. CDC noted that the flu season hasn't reached its peak yet and more infections are to be expected. Officials are advising those who did no received flu vaccines yet to get it as soon as possible.

So far, 20 children died because of the infection this season.