Background Recent reports demonstrate robust serological responses to a single dose of messenger RNA (mRNA) vaccines in individuals previously infected with SARS-CoV-2. Data on immune responses following a single-dose adenovirus-vectored vaccine expressing the SARS-CoV-2 spike protein (ChAdOx1 nCoV-19) in individuals with previous SARS-CoV-2 infection are however limited, and current guidelines recommend a two-dose regimen regardless of preexisting immunity. Methods We compared RBD-specific IgG and RBD-ACE2 blocking antibodies against SARS-CoV-2 wild type and variants of concern following two doses of the mRNA vaccine BNT162b2 in SARS-CoV-2 naïve healthcare workers (n=65) and a single dose of the adenovector vaccine ChAdOx1 nCoV-19 in 82 healthcare workers more than (n=45) and less than (n=37) 11 months post mild SARS-CoV-2 infection at time of vaccination. Findings The post-vaccine levels of RBD-specific IgG and neutralizing antibodies against the SARS-CoV-2 wild type and variants of concern including Delta lineage 1.617.2 were similar or higher in participants receiving a single dose of ChAdOx1 nCoV-19 vaccine post SARS-CoV-2 infection (both more than and less than 11 months post infection) compared to SARS-CoV-2 naïve participants who received two doses of BNT162b2 vaccine. Interpretation Our data support that a single dose ChAdOx1 nCoV-19 vaccine that is administered up to at least 11 months post SARS-CoV-2 infection serves as an effective immune booster. This provides a possible rationale for a single-dose vaccine regimen. Funding A full list of funding bodies that contributed to this study can be found in the Acknowledgements section
【저자키워드】 SARS-CoV-2, BNT162b2 vaccine, Neutralizing antibody response, Prior infection, ChAdOx1 nCoV-19, 【초록키워드】 neutralizing antibody, Vaccine, BNT162b2 vaccine, immune response, vaccination, Neutralizing antibodies, antibody, mRNA vaccine, SARS-COV-2 infection, variants of concern, Delta, variants, healthcare worker, immune, Spike protein, BNT162b2, mRNA, immune responses, SARS-CoV-2 spike protein, Lineage, wild type, ChAdOx1, funding, Preexisting immunity, ChAdOx1 nCoV-19, booster, single dose, ChAdOx1 nCoV-19 vaccine, Adenovirus-vectored vaccine, serological response, dose, regimen, (ChAdOx1 nCoV-19, Support, Messenger RNA, blocking antibodies, vectored vaccine, individual, naïve, participant, finding, mild SARS-CoV-2 infection, RBD-specific IgG, post infection, two-dose regimen, Post-vaccine, Administered, recent, effective, robust, RBD-ACE2, receiving, provide, less, contributed, expressing, infected with SARS-CoV-2, of BNT162b2, the SARS-CoV-2, 【제목키워드】 Antibody Response, healthcare worker, infected with SARS-CoV-2,