Short-lived common side effects including fever, chills, pain, and headache after mixing AZ with Pfizer vaccine reported in @TheLancet. Immunogenicity results to be reported in June and if mixing is a viable option (likely but assumption needs evidence).

Medical Mythbusting Commentary for May 13, 2021


Mixing Covid-19 vaccines tied to more side effects, early UK data suggests

Heterologous prime-boost COVID-19 vaccination: initial reactogenicity data