Robust antibody responses in 70–80-year-olds 3 weeks after the first or second doses of Pfizer/BioNTech COVID-19 vaccine, United Kingdom, January to February 2021
Sathyavani Subbarao, Lenesha Warrener, Katja Höschler, Keith R. Perry, Justin Shute, Heather Whitaker, Michelle O’Brien, Frances Baawuah, Paul Moss, Helen Parry, Shamez Ladhani, Mary Ramsay, Kevin Brown, Gayatri Amirthalingam
Abstract
Sera were collected from 185 adults aged ≥ 70 years in London to evaluate the immune response to COVID-19 vaccines. A single dose of Pfizer/BioNtech vaccine resulted in > 94% seropositivity after 3 weeks in naïve individuals using the Roche Spike antibody assay, while two doses produced very high spike antibody levels, significantly higher than convalescent sera from mild-to-moderate PCR-confirmed adult cases. Our findings support the United Kingdom's approach of prioritising the first dose and delaying the second dose of COVID-19 vaccine.