Americans who got flu shots last year were 25% less likely to test positive for COVID-19 as the disease spread across the country, research shows.
- A new study looked at more than 27,000 patients who tested positive for COVID-19 from March 2020 to mid-July 2020
- Of the 13,000 patients who received the flu shot, 4% contracted the coronavirus, versus 5% of the 14,000 patients who did not get the flu shot
- COVID-19 patients vaccinated against the flu were 40% less likely to be hospitalized and 100% less likely to be on mechanical ventilation
- Researchers are unclear if there is a biological or behavioral effect from the flu shot, as those who get the shot are more likely to distance themselves socially
Americans who got flu shots last year were significantly less likely to test positive for COVID-19, a new study suggests.
Researchers found that those vaccinated against the flu reduced their risk of contracting the virus, known as SARS-CoV-2, by 25 percent.
In addition, those who later became infected with the coronavirus had fewer complications if they were vaccinated against the flu.
The team, from Michigan Medicine, says the findings prove why the general public should get the flu shot if they haven’t already, despite the US approaching the end of the 2020-2021 flu season which may be on the wane . .
A new study found that of the 13,000 Michigan Medicine patients who got the flu shot, 4% contracted coronavirus, compared to 5% of the 14,000 patients who didn’t get the flu shot (file image)
COVID-19 patients vaccinated against the flu were 40% less likely to be hospitalized and 100% less likely to be on mechanical ventilation (above)
Senior author Dr. Marion Hofmann Bowman, associate professor of internal medicine at Michigan Medicine, said one of the inspirations behind the study was misinformation she had seen in connection with the flu vaccine with COVID-19 infection.
Despite several prominent media outlets debunking this claim, she said she wanted to address hesitation with vaccines.
“Rather than a worrying link between COVID-19 and the flu shot, our publication gives more confidence that getting your flu shot is associated with staying out of the hospital for COVID-19,” she said.
“It’s particularly relevant to vaccine hesitation, and perhaps taking the flu shot this year could ease fears about the new COVID-19 vaccine.”
For the study, published in American Journal of Infection Control, the team looked at medical charts of more than 27,000 patients who tested positive between March 2020 and mid-July 2020.
Researchers looked at flu shot status and checked for other factors such as age, race, gender, and pre-existing conditions.
Of the nearly 13,000 patients who received a flu shot last year, four percent tested positive for COVID-19.
In comparison, five percent of the 14,000 patients who did not receive a flu shot contracted coronavirus.
Next, the researchers looked at the difference in clinical results between COVID-19 patients with the flu vaccine and those without it,
Patients with a flu vaccine were 40 percent less likely to be hospitalized and 100 percent less likely to receive mechanical ventilation.
The hospital stay was also shortened in coronavirus patients who had received the flu shot in the hospital for an average of 12 days, compared to an average of 16 days for patients who had not received the flu shot.
However, there was no difference in death rates between the two groups of patients.
Hofman says it’s not clear what the link is between flu shots and COVID-19 disease or its severity.
“It’s possible that patients who get their flu vaccine are also people who take more social distance and follow CDC guidelines,” she said.
“However, it is also plausible that there could be a direct biological effect of the flu vaccine on the immune system that is relevant to the fight against the SARS-CoV-2 virus.”