Background To optimise the use of available SARS-CoV-2 vaccines, some advocate delaying second vaccination for individuals infected within six months. We studied whether post-vaccination immune response is equally potent in individuals infected over six months prior to vaccination. Methods We tested serum IgG binding to SARS-CoV-2 spike protein and neutralising capacity in 110 healthcare workers, before and after both BNT162b2 messenger RNA (mRNA) vaccinations. We compared outcomes between participants with more recent infection ( n = 18, median two months, IQR 2-3), with infection-vaccination interval over six months ( n = 19, median nine months, IQR 9-10), and to those not previously infected ( n = 73). Findings Both recently and earlier infected participants showed comparable humoral immune responses after a single mRNA vaccination, while exceeding those of previously uninfected persons after two vaccinations with 2.5 fold ( p = 0.003) and 3.4 fold ( p < 0.001) for binding antibody levels, and 6.4 and 7.2 fold for neutralisation titres, respectively (both p < 0.001). The second vaccine dose yielded no further substantial improvement of the humoral response in the previously infected participants (0.97 fold, p = 0.92), while it was associated with a 4 fold increase in antibody binding levels and 18 fold increase in neutralisation titres in previously uninfected participants (both p < 0.001). Adjustment for potential confounding of sex and age did not affect these findings. Interpretation Delaying the second vaccination in individuals infected up to ten months prior may constitute a more efficient use of limited vaccine supplies. Funding Netherlands Organization for Health Research and Development ZonMw; Corona Research Fund Amsterdam UMC; Bill & Melinda Gates Foundation.
【저자키워드】 COVID-19, SARS-CoV-2, Vaccine, BNT162b2, humoral immune response, neutralisation, 【초록키워드】 mRNA vaccination, immune response, vaccination, Infection, Sex, SARS-CoV-2 vaccines, outcome, organization, vaccine dose, Antibody binding, Corona, mRNA, healthcare, SARS-CoV-2 spike protein, age, development, funding, binding, Vaccinations, humoral, binding antibody, Messenger RNA, second vaccination, individual, foundation, participant, serum IgG, finding, uninfected, Neutralisation titres, neutralising, tested, nine, median, Netherland, increase in, comparable, not affect, Adjustment, IQR, Melinda Gate, neutralisation titre, uninfected participant, 【제목키워드】 SARS-COV-2 infection, BNT162b2 mRNA vaccination, time,