Immunogenicity of standard and extended dosing intervals of BNT162b2 mRNA vaccine

TLDR

The UK extended the interval between BNT162b2 mRNA vaccine doses to accelerate single‑dose coverage, and the first dose provided protection against the alpha variant for several weeks. This study sought to generate trial data on the immunogenicity of extended dosing intervals among UK healthcare workers. A prospective substudy of 589 healthcare workers measured SARS‑CoV‑2 neutralizing antibodies and sustained B‑ and T‑cell responses after a single dose and after extended intervals. Extended intervals (6–14 weeks) produced higher neutralizing antibody levels and enriched CD4⁺ T‑cell responses compared with the conventional 3–4 week regimen.

Abstract

Extension of the interval between vaccine doses for the BNT162b2 mRNA vaccine was introduced in the United Kingdom to accelerate population coverage with a single dose. At this time, trial data were lacking, and we addressed this in a study of United Kingdom healthcare workers. The first vaccine dose induced protection from infection from the circulating alpha (B.1.1.7) variant over several weeks. In a substudy of 589 individuals, we show that this single dose induces severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibody (NAb) responses and a sustained B and T cell response to the spike protein. NAb levels were higher after the extended dosing interval (6-14 weeks) compared with the conventional 3- to 4-week regimen, accompanied by enrichment of CD4