The overall estimate of the effectiveness of the influenza vaccine in keeping people out of doctors’ offices is 45%, according to the US Centers for Disease Control and Prevention. And that’s considered good for a flu vaccine, which is usually about 40% effective in preventing medically attended, laboratory-confirmed influenza infection. That estimate, released today and published in the CDC’s Morbidity and Mortality Weekly Report (MMWR), looks at how effective the flu vaccine was on 4112 children and adults with acute respiratory illness from October 23, 2019, to January 25, 2020.
There have been more cases of influenza B than A this flu season, and anyone can get either although children are more prone to type B. The CDC estimates that the vaccine has been about 50% effective against that strain in children. Against type A, it has been 55% more effective among children.
Brendan Flannery, PhD, the CDC’s investigator for the US Flu Vaccine Effectiveness Network, tells The Associated Press that “these estimates are reassuring.”
There were 14 pediatric deaths during the 2019-2020 flu season between weeks 52 and 56 (the weeks ending December 28, 2019, and February 8, 2020), according to CDC data. There have been 92 flu-related deaths for the same period this year. So far this season there have been at least 26 million flu illnesses, 250,000 hospitalizations, and 14,000 deaths from flu, according to the CDC.
Flannery is one of the authors of the MMWR study that points to an executive order issued by the White House on Sept. 19, 2019, calling for a modernization of flu vaccines.
“Current influenza vaccines are providing substantial public health benefits; however, more effective influenza vaccines are needed,” the study states. “Therefore, many US government agencies … are collaborating to improve influenza vaccines in support of the executive order….”
The CDC recommends that influenza antiviral medications should be used as an adjunct to vaccination. Antivirals should be given to any patient who has been hospitalized for the flu (or is suspected of having it), or is at high risk for flu complications, including children younger than 2 and adults older than 65 regardless of vaccination status or results of point-of-care influenza diagnostic testing. “Antiviral treatment can also be considered for any previously healthy symptomatic outpatient not at high risk for complications, with confirmed or suspected influenza, if treatment can be started within 48 hours of illness onset,” the study states.