ChAdOx1 nCoV-19 coronavirus vaccine: Long-term safety and immunological responses.
Ebrahimi N., de Whalley P., Kanji N., Ramasamy MN., Aley PK., Bibi S., Clutterbuck EA., Collins AM., Darton TC., Duncan CJA., Faust SN., Feng ES., Goodman AL., Green CA., Heath PT., Kwok J., Lazarus R., Libri V., Lillie PJ., McGregor A., Mujadidi YF., Owino N., Plested E., Pollock KM., Robinson H., Sutherland RK., Thomson EC., Toshner M., Turner DPJ., Williams CJ., Hirsch I., Villafana TL., Lambe T., Voysey M., Pollard AJ.
RATIONALE: Follow-up of pre-licensure trial participants potentially informs a vaccine's long-term safety profile. DESIGN: This prospective study enrolled participants from the first clinical trials of ChAdOx1 nCoV-19 vaccine, many of whom subsequently received COVID-19 vaccines in the UK vaccination programme. Serious adverse events (SAEs) and adverse events of special interest (AESIs) were captured. AESI selection was based on Brighton Collaboration definitions. RESULTS: Between September 2021 and April 2022, 4470 participants enrolled (58% female, median age 50 years); 3845/4470 (86.0%) completed the study. Median follow-up was 11.77 months; total follow-up was 48,116 person-months. There were 174 SAEs and 71 AESIs (33 events recorded as both) in 195 participants, including 5 deaths. Immunology data were available for a small subset of participants; total IgG against trimeric SARS-CoV-2 spike protein tended to increase during the study. CONCLUSIONS: Although no emergent safety signals were detected, continued post-marketing surveillance remains imperative, particularly for neurological disorders. EUDRACT NUMBER: 2021-003382-36.