Fact check: Flu vaccine hasn't eradicated the flu, but it has lessened the burden of the virus

The claim: The flu is still around, despite a vaccine

A post on Facebook claims the flu vaccine has been ineffective in eradicating the virus, despite existing for nearly eight decades.

"We've had a flu vaccine for 78 years," the post reads. "We still have the flu."

A black-and-white photo accompanying the text is of a child receiving one of the first free polio vaccines in St. Louis in April 1955, according to the St. Louis Post-Dispatch.

The image was posted by GZA, a rapper and founding member of the Wu-Tang Clan. 

GZA directed USA TODAY to a timeline from the Centers for Disease Control and Prevention on the flu from 1930 until today and said he was focused on "the information in the post" rather than the associated photograph of the polio vaccine.

The flu shot: How effective is it? Here's what doctors say

The flu vaccine was created 78 years ago, but the virus constantly changes

The CDC's timeline shows the first influenza vaccine was produced in 1942, and licensed for use in civilians in 1945 – 75-78 years ago.

By 1947, scientists realized the composition of the influenza virus had changed, rendering the vaccine ineffective. 

The "recurring mutations" of the influenza virus make it impossible to vaccinate against every strain of the flu. Each season's flu shot is composed of "the most frequent strains isolated in the previous season," according to a study in the Journal of Preventive Medicine and Hygiene. 

Fact check:2009 swine flu spread rapidly, but COVID-19 is more deadly

Sometimes, the previous season's strains are a close match with the upcoming season's strains – and sometimes, they're not. That impacts effectiveness.

Studies show that vaccination reduces the risk of illness by 40% to 60% when the flu viruses circulating are well-matched to the vaccine, according to the CDC.

Though the influenza vaccine has not eradicated the flu, it has lessened the burden of the virus on the USA. 

In the 2017-2018 flu season, vaccination prevented approximately 6.2 million illnesses, 3.2 million medical visits, 91,000 hospitalizations and 5,700 deaths, according to estimates from the CDC.

The CDC recommends that everyone over the age of 6 months receive annual flu vaccinations, except in "uncommon" cases of allergies or specific health histories.

Most experts agree it's worthwhile to get the shot.

Fact check:CDC did not add flu and pneumonia cases to its COVID-19 death count

Vaccines have eradicated other diseases, such as polio, from the country

The photo in the post depicts a child being vaccinated against polio, not the flu. Polio is an example of a disease that has been eradicated in the USA as a result of vaccines.

In the early 1950s, polio outbreaks caused more than 15,000 cases of paralysis each year, according to the CDC.

Need Clorox wipes? Disinfecting wipe shortage could last into 2021 amid coronavirus pandemic

After vaccines were discovered in 1955 and 1963, the number of cases fell rapidly, to fewer than 100 in the 1960s and fewer than 10 in the 1970s. The last case of polio that originated in the USA was in 1979, and there is "no year-round transmission of poliovirus in the United States," according to the CDC.

Other diseases that have been nearly eradicated in the USA include diphtheria, bacterial influenza, measles, mumps, rubella and tetanus, according to Vox.

Worldwide, two diseases – smallpox and rinderpest, a disease that affects cattle – have been wiped out.

Fact check:Masks can keep out COVID-19 particles even though they're smaller than drywall dust

Our rating: Missing context

Based on our research, the claim that the influenza virus still exists almost eight decades after the discovery of a vaccine is MISSING CONTEXT. It's true that the flu still exists – but there never was just one strain to eradicate, and the vaccine significantly lessens the burden of influenza on the USA each flu season.  

Our fact-check sources:

Thank you for supporting our journalism. You can subscribe to our print edition, ad-free app or electronic newspaper replica here.

Our fact check work is supported in part by a grant from Facebook.