The One Side Effect That's Much More Common With Moderna, Data Shows

Allie Hogan
·4 min read

Though you may not have much of a choice in terms of which company your COVID vaccine comes from, with three different ones on the market, you're probably curious how each of the vaccines might affect you. While the main side effects are consistent across the board with the Pfizer, Moderna, and Johnson&Johnson vaccines, there are some minor ways they're affecting patients differently. Using clinical trial data from the U.S. Food and Drug Administration (FDA), The Guardian created graphics demonstrating the most commonly reported side effects of each of the three vaccines available in the U.S. to help you prepare for what's to come with your shots. Read on to find out about the side effect that's much more likely to crop up with the Moderna vaccine, the one that's more common among Pfizer patients, and the couple that Johnson&Johnson patients seem to evade. Want to know if you're susceptible to a stronger reaction? Check out This Is Why Half of People Have Stronger Vaccine Side Effects, CDC Says.

Enlarged glands were only reported as a common side effect among those who got the Moderna vaccine.

Enlarged glands are a common immune response, but surprisingly this side effect was only commonly reported among people who received Moderna's vaccine. According to the data, it was the sixth most common side effect of Moderna's first shot, with 11.6 percent of people experiencing it. When it came to the second dose, 16 percent of Moderna patients had swollen glands.

Meanwhile, after their clinical trials, Johnson&Johnson and Pfizer did not report swollen glands as a common side effect of their vaccines. And for more on this particular side effect, check out The CDC Says Don't Do This Until 4 Weeks After Getting Vaccinated.

People who got the Pfizer vaccine more commonly reported diarrhea, but they had far less nausea.

Diarrhea was one of the top 10 most common side effects among people who got the Pfizer vaccine. According to clinical trial data, 11.1 percent of people reported diarrhea after their first dose from Pfizer, and 10.4 percent had it after their second dose.

While nausea and vomiting were reported among those who received the Moderna and Johnson&Johnson jabs, diarrhea was not commonly reported with those vaccines. According to the clinical trial data, 9.4 percent of people reported experiencing nausea and vomiting after their first dose from Moderna, a number that jumped to 21.3 percent after the second shot. With the single-dose Johnson&Johnson jab, 15.5 percent of patients reported experiencing nausea. Meanwhile, less than two percent of people who got the Pfizer vaccine experienced vomiting after either dose, and nausea wasn't among the top 10 side effects associated with that COVID vaccine. And for more up-to-date COVID news delivered straight to your inbox, sign up for our daily newsletter.

Not many people who got the Johnson&Johnson vaccine had chills or joint pain.

Chills are one of the top 10 most common side effects of the Moderna and Pfizer vaccines. Almost half of the Moderna patients reported the side effect after their second dose, and more than 35 percent of Pfizer patients reported chills after their second shots. On the other hand, according to the clinical data, chills were not even among the top 8 reported side effects of the Johnson&Johnson vaccine, meaning at the very most under nine percent of patients experienced this side effect.

Additionally, while joint pain was a common side effect for Moderna and Pfizer patients—with 45.2 percent of people experiencing it after their second dose of Moderna and 21.9 percent feeling the same after their second dose of Pfizer—it also was not listed as one of the top 8 Johnson&Johnson side effects. And for more on what to steer clear of close to your vaccination, check out Don’t Do This Two Hours Before or After Your Vaccine, Doctors Warn.

The top four most common side effects for all three vaccines were the same.

While there were some slight differences between the vaccines, the top four side effects were consistent for each: pain at the injection site, fatigue, headache, and muscle soreness.

In looking at how common they were, however, it's clear side effects are most prominent among those who received the Moderna vaccine, followed by the Pfizer vaccine (pain at the injection site after second dose: 90.1 percent versus 77.8 percent, fatigue after second dose: 67.6 percent versus 59.4 percent, headache after second dose: 62.8 percent versus 51.7 percent, and muscle soreness after second dose: 61.3 percent versus 37.3 percent).

Most of these side effects were substantially less prominent among Johnson&Johnson patients (pain at the injection site: 58.6 percent, headache: 44.4 percent, and fatigue: 43.8 percent). When it came to muscle soreness, it was on par with Pfizer with 39.1 percent reporting the side effect. And if you make it through your shots side effect free, check out This Is What It Means If You Have No Vaccine Side Effects, Doctors Say.