Flu Shots: Never More Important

That’s the advice from experts this year, who fear a “twindemic” of COVID-19 and influenza during the normal flu season. 

“It takes two to three weeks for the vaccine to build immunity in the body, and getting vaccinated early can help prevent transmission,” says Walt Orenstein, associate director of the Emory Vaccine Center and professor of infectious diseases at Emory’s School of Medicine.

And the flu virus, like the novel coronavirus, can be wily.

“Once exposed to influenza, an individual tends to get sick in a range of one to four days,” Orenstein says. “People are most contagious in the first three to four days of illness. But some people can transmit the virus before they even get sick and can also transmit from five to seven days after becoming sick.”

The flu virus can mutate, Orenstein says. There are about four major strains of influenza viruses in most vaccines. In the overall population, the CDC says studies show a vaccine can reduce the risk of flu by about 50% to 60% when the vaccine is well matched. 

Experts estimate the vaccine for the 2019–20 influenza season was about 38% effective. “We’d like a more effective vaccine,” Orenstein says, “but the [current vaccines] are still a lot better than zero percent, which is the effectiveness of no vaccination.”

Pregnant women are encouraged to get a flu shot to protect their newborns, since only babies 6 months of age and older can be vaccinated; the mother’s vaccination provides passive immunity to the newborn.

With the threat of COVID-19 as well as other illnesses that could lead to pneumonia, it’s even more important to get a flu shot this year. Having influenza and COVID-19 at the same time could be catastrophic for an individual, and having simultaneous or overlapping epidemics of influenza and COVID-19 would put tremendous stress on the health care delivery system.

—Dr. Walter Orenstein, speaking to WABE-FM, Sept. 16, 2020.