Common side effects of the COVID-19 vaccine include injection site reactions, headache, fatigue, and muscle pain. Side effects like nausea or diarrhea after the vaccine can potentially occur, but they're much less common.
Pain, redness, or swelling where the injection was given; headache; muscle or COVID-19 Vaccine joint pain; fever of 100.4°F (38°C) or higher; chills; upset stomach, throwing up, or diarrhea; swollen or tender glands; or feeling tired or unwell. Most side effects have been mild.
In some instances, digestive symptoms are reported as the initial presentation of COVID-19 (15). These findings suggest that the virus can impair the digestive system and may explain the range of digestive symptoms seen in COVID-19, including diarrhea, nausea, vomiting, and diminished appetite (16).
These symptoms do not mean you are sick. They signal that your immune system is responding to the shot and building up protection against the coronavirus.
Commonly reported side effects in the clinical trial included injection site pain (sore arm), redness and swelling, fatigue, headache, muscle and/or joint pain, chills, fever, swollen lymph nodes, nausea and decreased appetite.
It is normal to feel sick after getting a COVID-19 vaccine.
You may have a sore arm.
Put a cool, wet cloth on your sore arm.
This is normal and expected, but it doesn't happen to everyone. Even if you feel worse after the second shot, the side effects should still resolve within a few days.
“It's completely normal. It's your immune system reacting to the vaccine, as it should.”
The enlarged lymph nodes may feel like a lump and be a little tender, or you may not notice them at all, Dr.Roy adds.
A COVID-19 vaccine can cause enlarged lymph nodes in your armpit or near your collarbone on the side of your body where you received the injection.
If you experienced side effects when you were vaccinated initially, you may wonder if you'll have any noticeable symptoms in response to your booster shot. While you may have some side effects, they should be no worse than what you experienced originally and may well be milder.
Many people with COVID-19 experience gastrointestinal symptoms such as nausea, vomiting or diarrhea, sometimes prior to having fever and lower respiratory tract signs and symptoms.
COVID-19 is a disease caused by SARS-CoV-2 that can trigger what doctors call a respiratory tract infection. It can affect your upper respiratory tract (sinuses, nose, and throat) or lower respiratory tract (windpipe and lungs).
If your stomach troubles are due to a GI bug or food poisoning, you usually should feel better within 48 hours. If you don't, call your doctor. It could be a more serious bacterial infection or an early sign of COVID-19.
The most commonly reported side effects by individuals who received a booster dose of the Moderna COVID-19 Vaccine after completion of a two-dose primary series were pain, redness and swelling at the injection site, as well as fatigue, headache, muscle or joint pain and chills.
More common Pain, redness, or swelling at the injection site
Side effects that have been reported with the Janssen COVID-19 Vaccine include: Injection site reactions: pain, redness of the skin, and swelling. General side effects: headache, feeling very tired, muscle aches, nausea, fever. Swollen lymph nodes.
There is a remote chance that the Moderna COVID-19 Vaccine could cause a severe allergic
reaction. A severe allergic reaction would usually occur within a few minutes to one hour after
getting a dose of the Moderna COVID-19 Vaccine. For this reason, your vaccination provider
may ask you to stay at the place where you received your vaccine for monitoring after
vaccination. Signs of a severe allergic reaction can include:
• Difficulty breathing
• Swelling of your face and throat
• A fast heartbeat
• A bad rash all over your body
• Dizziness and weakness
“Overall, severe allergic reactions to COVID-19 mRNA vaccines, including life-threatening anaphylaxis reactions such as low blood pressure and difficulty breathing, are rare, on the order of five cases per million vaccine doses administered,” noted Dr. Guerrerio.
Multisystem inflammatory syndrome (MIS) is a rare but serious condition associated with COVID-19 in which different body parts become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs. MIS can affect children (MIS-C) and adults (MIS-A).
“Enlarged lymph nodes are visible as early as one day after vaccination, and they can remain enlarged for a month or more,” says Dr. Desperito. (Keep in mind that while you may stop feeling a swollen lymph node, which can feel like a lump in your armpit, it may still be visible on a scan.)
The swelling in the armpit was a recognized side effect in the large trials of the Moderna and Pfizer-BioNTech vaccines. According to The New York Times, in Moderna's study, "11.6% of patients reported swollen lymph nodes after the first dose, and 16% after the second dose.
An immediate allergic reaction happens within 4 hours after getting vaccinated and could include symptoms such as hives, swelling, and wheezing (respiratory distress).
Side effects can affect your ability to do daily activities, but they should go away in a few days.
To reduce pain and discomfort where the shot is given
COVID-19 vaccines can cause swelling in your lymph nodes or arm. Women who have been vaccinated against COVID-19 can develop enlarged underarm lymph nodes on the same side where they had the shot. It's more common for this to happen after boosters and additional doses.