Coming out of clinical trials, Moderna and Pfizer BioNTech reported some common side effects of the COVID vaccines, which typically lasted several days; those included pain at the injection site, tiredness, headache, muscle pain, chills, joint pain, swollen lymph nodes in the same arm as the injection, nausea, vomiting, and fever. The manufacturer said more people experienced these side effects after the second dose than after the first dose.