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The CDC just warned of 3 new coronavirus vaccine side effects

Published Mar 7th, 2021 1:37PM EST
Coronavirus Vaccine
Image: Aleksej/Adobe

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More than 283.5 million coronavirus vaccine doses have been administered worldwide as of Saturday morning, with nearly 60.6 million people having received the full two-dose regimen. An increasing number of studies offered additional data about vaccine efficacy in recent weeks. Israel has shown that the Pfizer/BioNTech vaccine works in real-life conditions just as well as it does in clinical trials. The vaccine effectively prevents severe COVID-19, hospitalizations, and deaths — even when facing the UK mutation. Researchers in Great Britain have come to similar conclusions, offering efficacy data for people who received only one dose of either the Pfizer or AstraZeneca/Oxford drugs. Separately, studies have shown that COVID-19 survivors mount the same immune response after one dose as people who never had COVID-19 get from two doses.

After almost three months of vaccinations in North America, Europe, Israel, and other countries, it’s also clear that the side effects are minimal. The most common adverse reactions include pain at the injection site and brief flu-like symptoms, especially after the second dose. But researchers have learned more details about coronavirus vaccine side effects in recent months. Now, the Centers for Disease Control and Prevention (CDC) has just updated its vaccine guidelines with three adverse effects people should be aware of.

Just a few days ago, researchers warned people that one specific mild COVID-19 vaccine side effect could appear several days after the first or second dose, rather than immediately: skin issues, including redness and rashes. These adverse reactions were observed after the Moderna jabs — especially after the first dose. They’re not a cause of concern, and they tend to disappear on their own within a few days.

The CDC made a few changes to its coronavirus vaccine guidelines on Friday, adding three new side effects to the list. Initially, the agency described six potential adverse reactions. Two are local (pain and swelling), and four are systemic (fever, chills, tiredness, and headache), as seen below.

Coronavirus Vaccine Side Effects
Coronavirus vaccine side effects listed in CDC guideline before March 5. Image source: CDC via Wayback Machine

The new guidelines include nine possible coronavirus vaccine side effects. In addition to pain and swelling on the arm where the shot is administered, people might also experience redness. As for the systemic reactions, the CDC added muscle pain and nausea to the list. Muscle pain should not be confused with pain at the site of injection.

Coronavirus Vaccine Side Effects
Coronavirus vaccine side effects listed in CDC guideline after March 5. Image source: CDC

These reactions are an indication that the immune system is responding to the perceived threat — the vaccine — and developing immunity. Coronavirus antibodies should begin to appear about two weeks after the first jab, and maximum protection is obtained about two weeks after the second injection.

The guidelines also provide helpful tips for dealing with the side effects. “Talk to your doctor about taking over-the-counter medicine, such as ibuprofen, acetaminophen, aspirin, or antihistamines, for any pain and discomfort you may experience after getting vaccinated,” the guidelines read. “You can take these medications to relieve post-vaccination side effects if you have no other medical reasons that prevent you from taking these medications normally.”

The CDC also reminds people that it’s not recommended to take these medications before vaccination in an effort to prevent the side effects.

After vaccination, people can use cool, wet cloths over the vaccine area to reduce pain and discomfort, and use or exercise the arm. Drinking plenty of fluids and dressing lightly can help with the general side effects that might appear. The CDC advises people to inform their doctors if these side effects do not go away after a few days. If the redness or tenderness in the arm gets worse after 24 hours, people should also consider contacting a doctor.

The CDC’s info about coronavirus vaccine side effects is available at this link.

Chris Smith Senior Writer

Chris Smith has been covering consumer electronics ever since the iPhone revolutionized the industry in 2008. When he’s not writing about the most recent tech news for BGR, he brings his entertainment expertise to Marvel’s Cinematic Universe and other blockbuster franchises.

Outside of work, you’ll catch him streaming almost every new movie and TV show release as soon as it's available.