covid vaccine and flu shot at the same time

Can Kids Get the COVID Vaccine and Flu Shot at the Same Time?

New research answers whether COVID and flu shots can be given together and whether any spacing is needed.

by Steve Silvestro, MD  @zendocsteve

You can also listen to this article as a podcast on your favorite podcast app or click on the player below:


If you happened to be standing anywhere near someone who’s a parent on October 7, 2021—the day that Pfizer asked the FDA to grant Emergency Use Authorization (EUA) to give its COVID vaccine to children aged 5–11—it’s very likely that you heard that parent make two distinct sounds:

  • First, a sigh of relief. At last, there’s hope that we can worry just a little bit less about some of our kids in the midst of this pandemic!
  • Next, a “huh…,” or a “hmmm…,” or some other utterance of question and wonder once that parent realized that this COVID vaccine is likely to start rolling out right around the time that their kids will be getting flu shots.

Indeed, my email, Instagram, and Facebook inboxes—which I admit I’ve been woefully negligent about of late—were soon peppered with variations of the following questions: “Can you get a COVID vaccine and a flu shot at the same time?” “How much space should there be between a flu shot and a COVID vaccine?” “Which order should you get a COVID vaccine and flu shot in?”

These are all valid questions—and, luckily, there are now answers!


On the most part, many vaccines that kids and adults receive can be given at just about any time—together at the same time, a day apart, a few days or a few weeks apart—any combination is usually okay.

That’s not the case with live vaccines, such as the MMR, chickenpox (varicella), and influenza nasal spray. With live vaccines, the disease-causing organism is kept alive, but weakened. The idea is that by knocking out the part that makes you sick, but keeping the organism alive, there will be a stronger and more effective immune response—and so better immunity—than if only a piece of the killed organism was in the shot like as is the case in most other vaccines.

That stronger immune response, however, impacts the timing of live vaccines. See, it appears that the best immune response occurs when live vaccines are either given together on the same day, or at least four weeks apart. For example, giving an MMR and a chickenpox vaccine two weeks apart might not lead to the best immunity. That’s why in kids, they’re often given at the same time or at different checkups altogether.

There are other instances in which timing of vaccines matters. These special circumstances tend to involve certain conditions children may have or treatments they may be receiving. For example, kids without a spleen, kids with HIV, or those undergoing chemotherapy might have unique spacing of necessary vaccines.


Luckily, there isn’t a version of the COVID vaccine that’s live. The Pfizer and Moderna vaccines deliver mRNA via a kind of fatty bubble called a lipid particle, and the AstraZeneca and Johnson & Johnson versions use a more traditional style involving a non-infectious adenovirus that carries coronavirus material to your cells. This all means that COVID vaccines should be okay to be given with other shots—including the flu shot—without any particular spacing needed.

However, when the COVID vaccines first rolled out for adults in early 2021, the CDC’s recommendation was to avoid getting another vaccine within two weeks of the COVID vaccine. Why? The reason then was so that we didn’t confuse reactions—because the COVID vaccine was new, we really wanted to be clear on whether a fever, fatigue, etc., was due to the COVID vaccine, and we didn’t want possible reactions from some other shot clouding the picture.

But now that we’ve had several months with millions of people aged 12 and up getting the COVID vaccine all around the world, we have quite a bit of experience with and insight into COVID-19 vaccines. We know the adverse reactions, we know the side effects, and we also have experience with some people getting other vaccines around their COVID-19 shots.

Because of this, the CDC now states thatCOVID-19 vaccines may be administered without regard to timing of other vaccines. This includes simultaneous administration of COVID-19 vaccine and other vaccines on the same day.”

When this updated statement was first made on September 27, 2021, the CDC noted that while it was clear that giving the COVID vaccine near other shots was generally safe, it wasn’t clear at the time whether the chances of reactions like fever or fatigue would be any higher.

Now, however, we do have that answer.


Just three days after the updated CDC recommendations, research was submitted to The Lancet showing exactly what happens when you give a flu shot and a COVID vaccine together.

Researchers in the UK gave 679 adults either an mRNA-based COVID vaccine (Pfizer) or a viral vector-based vaccine (AstraZeneca). Half of each group were also given a flu shot at the same time, while the other half were given a shot of placebo (don’t worry, those who were given placebo got to have a flu shot three weeks later).

The results? Effectiveness of the COVID and flu vaccines was similar whether given separately or at the same time. The same was true of side effects, with only a very slight bump in side effects reported in those who got the shots on the same day (85.2%) compared to those who got them on separate days (81.7%). And while an 80-85% rate of side effects sounds high, the vast majority of side effects were mild to moderate, with pain at the injection site being the most common, and things like feeling run down or mild fever also being common.

So based on this early research, it appears that getting the COVID and flu vaccines either together or three weeks apart will indeed be safe and effective.


Of course, nothing in this pandemic has been completely clear-cut, has it? With this study, there are a few caveats to keep in mind.

First, the people studied were getting their second dose of the COVID vaccine. We don’t have published research looking at combining a flu shot with the first dose—which is what some kids may be getting around the time of their flu shots.  However, there isn’t any indication that the effectiveness of the vaccines or rate of side effects should be any worse if the flu shot is given with the first COVID vaccine dose. In fact, most adults and teens experienced fewer side effects with their first COVID dose than their second.

The second caveat to this study is the obvious one—they studied adults, not kids. Still, there isn’t currently any cause to believe that kids would respond any differently than the aduts in this study.

All of this is to say that, like any major health decision, speak to your child’s pediatrician to see what makes the most sense for your family.

Then, perhaps, you can utter a sigh of relief once more.

Important links:

Get my FREE Children’s Medication Dosing Guide