Full Answer
If you get a COVID-19 vaccine and you think you might be having a severe allergic reaction after leaving the vaccination provider site, seek immediate medical care by calling 911.
An immediate allergic reaction happens within 4 hours after getting vaccinated and could include symptoms such as hives, swelling, and wheezing (respiratory distress).
Delayed urticarial reactions — Occasionally, patients develop a few hives and/or mild angioedema several hours or days after administration, as with other vaccines.
Some people have no side effects. Many people have reported side effects, such as headache, fatigue, and soreness at the injection site, that are generally mild to moderate and go away within a few days.
“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.
Symptoms of anaphylaxis often occur within 15-30 minutes of vaccination, though it can sometimes take several hours for symptoms to appear.
Skin problems such as itchiness, rashes, hives and swelling can occur in some individuals after receiving a COVID-19 vaccine, but it's not clear how common these reactions are or how frequently they recur with a subsequent vaccination.
You probably experienced COVID-19 vaccine side effects fairly quickly when you had your initial injections. The same is true for COVID-19 vaccine booster shots: Most people notice side effects within the first 24 hours. The symptoms typically only last a day or two. Some people don't notice any side effects.
Monitoring of the Moderna COVID-19 vaccine has found 10 cases of anaphylaxis after the administration of 4,041,396 first doses of the Moderna COVID-19 vaccine. In 9 out of these 10 cases of anaphylaxis, the recipient of the vaccine had onset of symptoms within 30 min of administration.
Benefits of Vaccination Outweigh the Risks Serious side effects that could cause a long-term health problem are extremely unusual following any vaccination, including COVID-19 vaccination.
Serious adverse events, while uncommon (<1.0%), were observed at slightly higher numerical rates in the vaccine study group compared to the saline placebo study group, both overall and for certain specific adverse events occurring in very small numbers.
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.