HealthDay News — Individuals with previous 1ere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection generate strong responses to one dose of the BNT162b2 vaccine, according to 2 research letters published online Feb. 25 in The Lancet.

Maria Prendecki, PhD, from Imperial College London, and colleagues investigated immunological responses to single-dose BNT162b2 among 72 health care workers (HCWs) who were vaccinated between Dec. 23 and 31, 2020. Twenty-one of the participants had evidence of previous SARS-CoV-2 infection and 51 were defined as infection-naive. The researchers found that postvaccination, anti-S titers were significantly higher in individuals with previous natural infection than infection-naive participants. In a subset of participants, in those with previous exposure, the vaccine induced very strong neutralizing antibody titers; vaccination induced detectable neutralizing antibodies in infection-naive individuals, but titers were lower. Those with evidence of previous SARS-CoV-2 infection at baseline mounted very strong T-cell responses to spike peptides; these responses were significantly weaker in the infection-naive group.

Charlotte Manisty, MD, PhD, also from University College London, and colleagues undertook a nested case-control analysis of 51 participants of an ongoing longitudinal observational study of HCWs, 24 of whom had previous laboratory-confirmed mild or asymptomatic SARS-CoV-2 infection. All participants received their first dose of the BNT162b2 mRNA COVID-19 vaccine and were tested 19 to 29 days after. The researchers found that vaccination increased anti-S titers more than 140-fold from peak prevaccine levels among those with a previous SARS-CoV-2 infection. This increase was at least one order of magnitude greater than reported after a conventional prime-boost vaccine strategy in previously uninfected individuals.

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“Our findings provide a rationale for serology-based vaccine dosing to maximize coverage and impact,” Manisty and colleagues write.

Several authors from both studies disclosed financial ties to Oxford Immunotec.

Abstract/Full Text – Prendecki

Abstract/Full Text – Manisty