WASHINGTON — COVID-19 has disrupted medical care, priorities and routine treatments and that's why the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) said it's so important for everyone to get a flu shot this year.
Both COVID-19 and the four main strains of influenza are contagious respiratory illnesses but are caused by different viruses.
There are claims spreading on social media that the influenza vaccine causes false positives on COVID-19 tests. So we're verifying if that claim is true or false.
THE QUESTION
Can the flu shot cause you to inadvertently test positive for COVID-19?
THE SOURCES
THE ANSWER
No, the flu shot won't make you test positive for COVID-19. Both the CDC and the FDA said that flu vaccines contain no type of coronavirus, like the one that causes COVID-19.
On the CDC's "Myths and Facts about COVID-19 Vaccines" page, it says none of the authorized and recommended COVID-19 vaccines cause you to test positive on viral tests, which are used to see if you have a current infection.
NASEM explains that COVID-19 and the flu are different diseases. SARS-CoV2 causes COVID-19 and the influenza virus causes the flu.
The flu shot causes your body’s immune system to make antibodies that protect you from influenza.
These antibodies are different from the ones you make to fight an infection caused by the novel coronavirus.
Now, if you take an antibody test to see if you’ve fought a COVID-19 infection in the past, that test looks for antibodies unique to the SARS-CoV 2 coronavirus. The test does not look for antibodies for the flu.
If you get a diagnostic test to see if you currently have a COVID-19 infection, that test looks for genetic material unique to the novel coronavirus. It does not look for influenza viruses.
So, the bottom line is whether you’re tested for a current COVID-19 infection or to see if you previously had COVID-19, the flu shot will not cause a false-positive test result for either tests.
