Symptoms After COVID-19 Vaccination Tied to Higher Antibody Levels

People who experienced such symptoms as chills, tiredness, headaches, and feeling unwell after receiving a SARS-CoV-2 messenger RNA vaccine had higher blood levels of neutralizing antibodies, which might play a role in protecting people from COVID-19 infection, according to data published in the Annals of Internal Medicine. The data were based on a prospective cohort study of 363 participants in the US who were vaccinated in 2021 and self-reported their symptoms.