The Flu Shot: Separating Myth from Fact

September 2019

The CDC estimates that between 9 million and 49 million people fall ill from the flu each year, leading to more than 200,000 hospitalizations and tens of thousands of deaths annually. But as a recent University of Chicago survey noted, almost 40 percent of American adults still skip the flu shot.

There are many reasons why people may avoid this vaccine — but some of the most common excuses for skipping the annual flu shot are based on myths and misconceptions about what this vaccine is and how it can protect you — and your community.

Here are some of the most pervasive myths about the flu shot:

MYTH: The flu shot works only if you get it before November.

FACT: The CDC recommends that people get vaccinated before the onset of the flu season, which is generally in early November. Since it takes approximately two weeks after the flu shot for your body to develop the protective antibodies, getting vaccinated at the beginning of the school year, or no later than Halloween, offers the greatest protection. However, there’s a reason why the flu vaccine is available throughout the flu season: Just two weeks later, you’ll be covered for the rest of the season. This is especially important if the flu season runs late, as it did in the 2018-2019 season. If you have questions about whether you would benefit from a flu vaccine, talk to your doctor or pharmacist.

MYTH: The flu vaccine can give you the flu.

FACT: While the flu vaccine can result in some side effects, including headaches, fever and muscle aches, in approximately one to two percent of people, the flu shot won’t infect you with the influenza virus. According to the CDC, flu vaccines use either inactivated viruses or specific genes from different strains of influenza (isolated from the viruses and then transformed into vaccine form) in order to help your body build protective antibodies. Neither inactivated viruses nor the gene-based vaccines are infectious. So while you may experience a few mild but annoying side effects after receiving a flu vaccine, these symptoms are decidedly not the flu — and won’t last for more than a day or two.

MYTH: The flu shot is only for people with a compromised immune system.

FACT: Even healthy people can get the flu. As noted above, the CDC estimates that approximately five to 20 percent of Americans will be infected each year. By receiving a flu vaccination, you can not only protect yourself (and save yourself a week in bed or worse) but also protect your friends, family and broader community, especially those who may suffer from a compromised immune system.

MYTH: Flu vaccines can cause autism.

FACT: Absolutely false. In the late 1990s, a controversial study suggested there was a link between the measles, mumps and rubella (MMR) vaccine and the later development of autism. In the years since, this study has been thoroughly debunked, several times over — and studies looking at other vaccines, like the flu vaccine, have demonstrated they do not cause autism. According to the CDC, multiple studies have shown there is no link between vaccines, or vaccine ingredients, and the development of autism. This includes the flu vaccine.

MYTH: The flu vaccine won’t really stop you from getting the flu.

FACT: Each year’s flu vaccine contains protection against a few viruses that the CDC deems as most prevalent (or dangerous) in a given flu season. The vaccine will protect you from picking up those specific strains, but it may leave you vulnerable to others that are very different from those selected. That said, some vaccinated people may still catch one of the strains included in the current year’s vaccine. But studies show that when that occurs, individuals who are vaccinated experience less severe symptoms and fewer flu-related complications and are much less likely to require hospitalization during the course of their illness. So even if you do pick up a flu virus, you are still better off being vaccinated.

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