Among patients receiving mRNA vaccines, clinically significant symptoms were more frequent following dose 2, following dose 1 in patients with previous SARS-CoV-2 infection, and in those who received the Moderna vaccine.

Association of Vaccine Type and Prior SARS-CoV-2 Infection With Symptoms and Antibody Measurements Following Vaccination Among Health Care Workers – JAMA Internal Medicine

Commentary on Twitter

New @JAMA_current paper says @moderna_Tx caused 2.3x the number of "significant" symptoms compared to @pfizer in a sample of 950 people.

Moderna also produced more antibodies. Raising the question of what a third dose, which produces still MORE, will do.https://t.co/drvhhsnpHo

— Alex Berenson (@AlexBerenson) August 16, 2021