A study published last week in the Journal of Dental Research found that dental health-care professionals (DHCPs) had higher rates of SARS-CoV-2 infection in the UK's first wave of the pandemic than the general population, and measured the protection antibodies produced by infection provide.
The study authors collected blood samples from about 1,500 clinicians in the Midlands area of the United Kingdom in June 2020. The samples were tested for antibodies to SARS-CoV-2. Of the study participants, 16.3% had antibodies, compared with just 6% of the general population at the time. The authors of the study concluded that these findings "[support] the hypothesis that occupational risk arose from close exposure to patients."1
Study participants gave blood samples three and six months later. These samples demonstrated that "over 70% continued to have SARS-CoV-2 antibodies both at three months and six months later, and they were at a 75% reduced risk of reinfection with the virus."1
The study also found that those participants who did not have antibodies prior to vaccination demonstrated a "robust immune response" to the Pfizer vaccine, and notably, that none of the participants who had antibody levels above 147.6 IU/ml tested positive for COVID-19 (i.e., experienced reinfection) in the six months of the study. However, only 5.3% of those who were infected and testing positive for antibodies reached the threshold of 147.6 IU/ml.
Participants who had evidence of previous infection also demonstrated a "rapid and robust" response to a single dose of the Pfizer vaccine.1
- Study of UK dental professionals reveals extent of occupational risk of SARS-CoV-2 infection. University of Birmingham. June 3, 2021. Accessed June 4, 2021. https://www.birmingham.ac.uk/news/latest/2021/06/study-of-uk-dental-professionals-reveals-extent-of-occupational-risk-of-sars-cov-2-infection.aspx