Oct 4, 2021
Why it’s safe to get both the flu shot and COVID-19 vaccine
Interested in getting both the flu shot and the COVID shot – but want to make sure you are making the best choices for your health?
Dr. Daniel Kuritzkes, chief of infectious disease at Brigham and Women’s Hospital, talked to Coverage about why it’s safe to get both vaccines at once, and helped debunk some common social media myths.
Myth #1: The side effects will be worse
Some people are concerned that getting both shots at once, or within a few days of each other, will result in more severe side effects than just getting one. However, the CDC states that “experience with giving other vaccines together has shown the way our bodies develop protection and possible side effects are generally similar whether vaccines are given alone or with other vaccines.”
Initially, the CDC said people should wait two weeks between shots. But now that more data has been gathered, that recommendation has been modified.
“The side effects will be about the same either way,” Kuritzkes said. “Most people have minimal reaction to flu vaccine. Any resulting aches or pains should be resolved with over-the-counter pain medication.”
Myth #2: The vaccines will interact negatively
The flu and COVID-19 vaccines are completely different types of shots that elicit unrelated reactions within the body, Kuritzkes said. They prompt different immune responses and antibodies to fight off the respective viruses.
For decades, it has been common to get vaccinated against several illnesses at once -- young children and new parents, for instance, often receive combination shots like the TDaP shot for diphtheria, pertussis and tetanus.
Moderna is developing a combination shot that would give a COVID-19 booster and flu vaccine in one dose.
“There is absolutely no reason that the two shots would interact negatively,” Kuritzkes said. “The only potential for a worse outcome is having two sore arms instead of one.”
Myth #3: The flu shot leads to increased risk of COVID-19
A stream of misinformation has suggested that flu vaccination might raise the risk of COVID infection, erroneously pointing to a study that examined whether the seasonal flu shot may increase the risk of other respiratory viruses. That study found “little to no evidence supporting the association of virus interference and influenza vaccination.”
Researchers in Canada also later found that flu vaccination did not increase risk for seasonal coronaviruses.
“For the flu shot to give you COVID-19, it would need to contain the virus, which it does not,” Kuritzkes said.
Myth #4: The flu shot can cause a false positive for COVID-19
Anti-vaccine advocates have claimed that anyone who has had the flu shot in the last 10 years would test positive for COVID-19.
But there is no possibility this could be true, Kuritzkes said.
Flu vaccines contain either an inactivated flu virus incapable of causing infection, or a gene from the flu virus that causes an immune response but is too weak to cause infection.
“There's nothing in the flu vaccine that would lead you to have a positive COVID-19 test result, no matter the test,” he said.
“Yes, you can get a COVID-19 vaccine and a flu vaccine at the same time,” the Centers for Disease Control and Prevention says. “Get a COVID-19 vaccine as soon as you can, and ideally get a flu vaccine by the end of October.”
For more information, visit the CDC’s flu vaccine page.
Image of Dr. Daniel Kuritzkes from Brigham and Women’s Hospital