Many Americans believe they don't need flu shots

Flu season is in swing and likely won't let up until April.

It seemed like high time to check in on how Americans feel about flu vaccination, so we asked more than 3,000 adults in the latest NPR-Truven Health Analytics Health Poll, conducted during the first half of October.

All told, 62 percent of people said they had been vaccinated or intended to get vaccinated against flu.

Those who hadn't been immunized and don't plan on it cited a variety of reasons. The top factors include a belief that a flu shot (or spray) is unnecessary for them (48 percent of the group), concerns about side effects or risks (16 percent) and worries that the vaccine could infect them with the flu (14 percent). About 8 percent of the people who plan to skip vaccination said it's because they believe it's ineffective.

Cost didn't seem to be a significant barrier. More than three-quarters of those who had received the flu vaccine said it cost them nothing out of pocket.

"Education didn't make much of a difference. Income was not a big differentiator. Age was really the biggest differentiator," Dr. Michael Taylor, Truven's chief medical officer, tells Shots.

Those over 65 years of age were the most likely to have been vaccinated this year.

Data from the National Center for Health Statistics show the proportion of vaccinated Americans has increased since 1997, with dips in 2000 and 2004 because of vaccine shortages. But many adults choose not to get it, a phenomenon supported by this poll.

Taylor says it was surprising that so many "people surveyed don't understand what they need to know about the vaccine. I thought that was kind of amazing, frankly."

Seasonal flu-related complications result in about 200,000 hospitalizations in the U.S. each year. On average, about 25,000 people in the United States die from influenza each year. "That's a large number of people. The vaccine is really the best way to prevent those infections," says Ryan Malosh, an epidemiologist at the University of Michigan School of Public Health. In a study of about 550 people, Malosh found that adults who received the vaccine reported these as the most important factors in their decision: recommendation from a health care provider (47 percent), living or working with high-risk individuals (44 percent) and wanting to lower their own risk of disease (90 percent). Vaccination reduces transmission, because even if the flu doesn't make one person particularly ill, it's possible for him or her to pass it to someone who could experience much more severe symptoms. Vaccination also helps limit transmission through something called herd immunity.

Since 2010, the Centers for Disease Control and Prevention has recommended vaccination for everyone except people who are allergic to the vaccine or who are younger than 6 months old.

Shannon Stokley, an epidemiologist with the immunization services division of the CDC, says last year, 47 percent of Americans 6 months and older received the flu vaccine. Two-thirds of adults over 65 received it. One-third of adults ages 18 to 49 did.

She thinks some misconceptions about flu cloud people's views of the benefits of vaccination. "People tend to minimize it," Stokley says. "They think, 'Oh, it's like a cold.' But it's actually much more serious than that, and they don't realize how important the vaccine is to protect against that disease."

The language we use is part of the problem. "We say 'I have the flu,' or 'I have the stomach flu.' We use that word to represent any sort of illness. But flu is very specific — it's an infection caused by the influenza virus."

Stokley says she's familiar with the argument that people don't need it or that it will make them sick. "Yes, we do hear both of those reasons frequently," she says.

Stokley says side effects of the vaccine, like soreness at the injection site or a minor fever, can lead people to assume it made them ill.

"But those are normal reactions from the vaccine and they typically go away within a day or two," says Stockley. In fact, a small fever can be evidence that the vaccine is actually working — an indication that the body has built up antibodies so that if the actual flu virus comes around, the immune system is ready. "It's your body mounting the immune response," says Stokley.

"The virus that is included in the vaccine is either killed or weakened, so you just cannot get the flu from the flu vaccine," says Stockley. "I don't think they appreciate how serious influenza disease can be."

The Spanish flu of 1918 killed more people than World War I did, and the virus was most deadly for people ages 20 to 40. But even with today's resources, the seasonal flu can be problematic. Stokley points to a study from 2012 showing that flu vaccination reduced children's risk of pediatric intensive care unit admission by 74 percent. Another study found that flu vaccination was associated with a 71 percent reduction in flu-related hospitalizations among adults of all ages. Flu can exacerbate chronic conditions like asthma and heart disease. One of the strains last year was particularly virulent. Stokley says it led to the deaths of 145 children, "one of the highest levels we've seen in a long time," and caused hospitalizations for people 65 years and over to be the highest since 2005. It takes about two weeks after vaccination for the protection to set in. This year's flu vaccine is expected to be more effective than last year's at fending off prevalent flu strains. The NPR-Truven Health Analytics Health Poll was conducted in October with 3,008 participants. The margin for error is plus or minus 1.8 percentage points. You can find the questions and full results of the latest poll here. For previous polls, click here. Copyright 2019 NPR. To see more, visit https://www.npr.org.