by With the holiday season in full swing, you may realize you forgot to get your Covid-19 and flu shots, and now you’ll be sitting across the table from your elderly loved one.
The good news is that it’s not too late to get your shots, but what about hitting them both at the same time? The US Centers for Disease Control and Prevention says this is an option, but should you?
A recent study of Medicare claims data found a slightly increased risk of stroke — but still very rare — for seniors who receive a high-dose flu vaccine and a Covid-19 shot at the same time. The risk was about 3 strokes per 100,000 doses of Pfizer’s bivalent Covid vaccine and about 3 transient ischemic attacks per 100,000 doses of Moderna’s bivalent Covid vaccine. Other studies have not found the same risk, leading the CDC and the US Food and Drug Administration to say that their vaccine recommendations are unchanged at this time. Covid-19 vaccines were updated this year to target one strain of the coronavirus instead of two.
Also, if you get both shots at the same time it seems a little more likely that you will have a temporary reaction to the shots; the most common symptoms reported in a government study were fatigue, headache and muscle pain.
CDC Director Dr. Mandy Cohen told CNN that the most important thing is that people get their vaccines at all — and that early in the respiratory virus season is a good time to do it.
“It’s definitely OK to get multiple vaccines on the same day,” Cohen said. “I would talk to your doctor or nurse practitioner about what’s right for you.”
Does co-administration affect protection?
But what about efficiency? Do the two shots together affect how well they work?
This is where there may be upside.
A small study presented at the Vaccines 2023 conference in Boston recently found that healthcare workers who received flu and bivalent Covid-19 shots on the same day after receiving them had higher antibody responses. as well as six months later, compared to humans. who received their shots on different days.
Susanna Barouch, a high school student in Cambridge, Massachusetts, who led the research, said she thinks that giving the shots at the same time might trigger a stronger immune system response to shots. “The flu vaccine could be an adjuvant to the Covid vaccine,” she said.
But this is not the only study to look at the issue, and marginally, other studies have come to the opposite conclusion or basically found no difference between giving vaccines together or vaccines one at a time.
This is one of the first studies to find that co-administration increases antibody levels, and Barouch says his findings need to be replicated before they can be accepted as fact.
“Certainly, I would say this is far from settled,” said Stephen Moss, a researcher at the University of Michigan.
Moss led a recent study that compared the neutralizing antibody responses of 53 Israeli healthcare workers who received their bivalent Covid-19 vaccines separately or with a flu shot.
Blood samples from these healthcare workers were also able to prevent the Covid-19 and flu viruses from infecting cells, whether they received their vaccines together or separately.
A study from the Netherlands, published in June, found that antibodies after co-administration showed a significantly lower neutralizing capacity compared to a reference group that received their vaccines separately.
Moss said most studies of co-administration found “a small increase, a small decrease or no change at all,” in antibody levels, he said.
What that means, he says, is that from a wider public health perspective, it’s probably a good idea to recommend that people get both at the same time.
“It cuts down on doctor visits. It reduces the number of contacts you have to have with the healthcare system. It also reduces the number of days you feel like crap after the vaccine. So you only have to go through that once instead of twice,” Moss said.
Real world results
Encouragingly, in a large recent study by researchers at Pfizer, which looked at the health outcomes in people who received their flu and Covid-19 vaccines together or separately, little difference was found between these groups .
The study found that rates of hospitalizations, emergency room visits and doctor visits were the same between the two groups. Overall, the group who received both shots at the same time were slightly more likely to visit the doctor or emergency room for Covid-19 but less likely to need medical care for the flu, suggesting that both shots improved immune defense against flu infections together. .
So it’s largely a matter of personal choice that you get your vaccines, but Dr. William Schaffner, an expert on infectious diseases at Vanderbilt University, that it makes a lot of sense to get together, especially in the last season.
“I want to remind everyone that a vaccine that is delayed is often not received, because you have to make another attempt to get in,” he said.
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