With the holiday season underway, you may realize that you forgot to get vaccinated against Covid-19 and the flu, and now you will be sitting in front of your elderly relatives.
The good news is that it’s not too late to shoot, but how about we knock them both out at the same time? The US Centers for Disease Control and Prevention says this is an option, but should you do it?
A recent study of Medicare claims data found a slightly increased, but still very rare, risk of stroke in older people who receive a high dose of the flu vaccine and the Covid-19 vaccine at the same time. time. The risk was approximately 3 strokes per 100,000 doses of the Pfizer bivalent Covid vaccine and approximately 3 transient ischemic attacks per 100,000 doses of the Moderna bivalent Covid vaccine. Other studies have not found the same risk, prompting the CDC and the U.S. Food and Drug Administration to say there is no change to their vaccine recommendations at this time. Covid-19 vaccines were updated this year to target one strain of the coronavirus instead of two.
Beyond that, receiving both injections at the same time seems make it slightly more likely that you will experience a temporary reaction to the injections; 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 for people to get vaccinated, and that the beginning of respiratory virus season is a good time to do so.
“It’s definitely okay to get multiple vaccines on the same day,” Cohen said. “I would talk to your doctor or nurse practitioner about what is best for you.”
But what about effectiveness? Does the effectiveness of both injections together affect their effectiveness?
This is where there could be an advantage.
A small study presented at the recent Vaccines 2023 conference in Boston found that healthcare workers who received flu vaccines and the bivalent Covid-19 vaccine on the same day had higher antibody responses immediately after receiving them, as well like six months later, compared to people. who received their vaccines on different days.
Susanna Barouch, a high school student in Cambridge, Massachusetts, who led the research, said she believes giving the injections at the same time may stimulate the immune system to react more strongly to the injections. “The flu vaccine could have been an adjuvant to the Covid vaccine,” she said.
But this was not the only study to look at the issue, and surprisingly, other studies came to the opposite conclusion or found essentially no difference between giving the vaccines together or one at a time.
This is one of the first studies to find that co-administration increases antibody levels, and Barouch says its findings need to be replicated before they are accepted as fact.
“I would definitely say this is far from resolved,” 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 vaccine.
Blood samples from these healthcare workers were still able to prevent Covid-19 and flu viruses from infecting cells, whether they received the vaccines together or separately.
A study from the Netherlands, published in June, found that antibodies after co-administration showed significantly lower neutralization capacity compared to a reference group that received their vaccines separately.
Moss said most coadministration studies have found “a slight increase, a slight decrease, or no change” in antibody levels, he said.
What that means, he says, is that from a broader public health perspective, it’s probably a good idea to recommend that people get both at the same time.
“Reduce visits to the doctor. Reduces the number of encounters with the healthcare system you must have. It also reduces the number of days you feel sick after the vaccine. So you only have to go through it once and not twice,” Moss said.
Reassuringly, a recent large study by Pfizer researchers, which looked at health outcomes in people who received the flu and Covid-19 vaccines together or separately, found few differences between these groups.
The study found that rates of hospitalizations, emergency room visits, and doctor visits were similar between both groups. Overall, the group that received both vaccines at the same time was 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 receiving both vaccines together improved immune protection against influenza infections. .
So how you get vaccinated depends largely on personal preference, but Dr. William Schaffner, an infectious disease expert at Vanderbilt University, says vaccinating them together makes a lot of sense, especially at this stage of the season.
“I would just like to remind everyone that a delayed vaccine is often a vaccine that is never received, because you have to make an extra effort to get in,” he said.