COVID 19: Seroprevalence and vaccine responses in UK dental care professionals

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Authors

Abstract

Background: Dental care professionals (DCPs) are thought to be at enhanced risk of occupational exposure to SARS51 CoV-2. However, robust data to support this from large-scale seroepidemiological studies is lacking. We report a longitudinal seroprevalence analysis of antibodies to SARS-CoV-2 spike glycoprotein, with baseline sampling prior to large-scale practice re-opening in July 2020 and follow-up post-implementation of new public health guidance on infection prevention control (IPC) and enhanced personal protective equipment (PPE).

Methods: 1,507 West Midlands DCPs were recruited into this study in June 2020. Baseline seroprevalence was determined using a combined IgGAM ELISA and the cohort followed longitudinally for 6 months until January/February 2021 through the second wave of the COVID-19 pandemic in the United Kingdom, and vaccination commencement.

Results: Baseline seroprevalence was 16.3%, compared to estimates in the regional population of 6-7%. Seropositivity was retained in over 70% of participants at 3- and 6-month follow-up and conferred a 75% reduced risk of infection. Non-white ethnicity and living in areas of greater deprivation were associated with increased baseline seroprevalence. During follow-up, no PCR-proven infections occurred in individuals with a baseline anti-SARS-CoV-2 IgG level greater than 147.6 IU/ml with respect to the World Health Organization international standard 20-136. Post-vaccination, antibody responses were more rapid and of higher magnitude in those individuals who were seropositive at baseline.

Conclusion: Natural infection with SARS-CoV-2 prior to enhanced PPE was significantly higher in DCPs than the regional population. Natural infection leads to a serological response that remains detectable in over 70% of individuals 6 months after initial sampling and 9 months from the peak of the first wave of the pandemic. This response is associated with protection from future infection. Even if serological responses wane, a single dose of the Pfizer-BioNTech 162b vaccine is associated with an antibody response indicative of immunological memory.

Details

Original languageEnglish
JournalJournal of Dental Research
Early online date2 Jun 2021
Publication statusE-pub ahead of print - 2 Jun 2021

Keywords

  • dentistry, SARS-CoV-2, vaccination, antibodies, seroepidemiological studies, occupational exposure