Tolerability and Immunogenicity After a Late Second Dose or a Third Dose of ChAdOx1 nCoV-19 (AZD1222)

Preprint (not yet peer reviewed) reports extending interval between 1st & 2nd dose of AZ vaccine to 45wks resulted in higher antibody titres, and a 3rd dose given 44-45wks after the 2nd increased titres further. However, there is currently no indication that a booster is needed.

Preprints with The Lancet