Prevalence of SARS-CoV-2 Antibodies in First Responders and Public Safety Personnel

New York City, New York, USA, May-July 2020

Samira Sami; Lara J. Akinbami; Lyle R. Petersen; Addie Crawley; Susan L. Lukacs; Don Weiss; Rebecca A. Henseler; Nga Vuong; Lisa Mackey; Anita Patel; Lisa A. Grohskopf; Beth Maldin Morgenthau; Demetre Daskalakis; Preeti Pathela


Emerging Infectious Diseases. 2021;27(3):796-804. 

In This Article


This cross-sectional survey was conducted during May 18–July 2, 2020, in the 5 NYC boroughs: Brooklyn, Manhattan, Queens, Staten Island, and the Bronx. The Institutional Review Board of the NYC Department of Health and Mental Hygiene and Centers for Disease Control and Prevention (CDC) human subjects research officials determined this activity to be public health surveillance as defined in 45 CFR 46.102(l).[2]

Adults ≥18 years of age working onsite in a public service agency were eligible to participate, including employees of city departments of corrections, police, fire, medical examiner, and education, for a total of ≈60,000 persons. Educational settings were limited to Regional Enrichment Centers that served children of first responders and healthcare personnel. Persons who self-reported a positive result for SARS-CoV-2 or occurrence of COVID-19 symptoms ≤2 weeks before completing the questionnaire were ineligible.

A questionnaire assessed participant demographics and relevant household, occupation, and workplace risk factors for SARS-CoV-2 infection (Appendix Table 1, Participation was voluntary. Consenting participants completed the questionnaire online and provided a blood specimen at a collection site located at or near their workplace during May 18–July 2, 2020. Samples were tested for SARS-CoV-2 antibodies by using the VITROS Immunodiagnostic Products Anti-SARS-CoV-2 IgG Test (ORTHO Clinical Diagnostics Inc., Data for this test submitted to the Food and Drug Administration indicated a sensitivity of 90% and a specificity of 100%.[2] Some tests were not performed because of lipemia or insufficient serum. CDC did not receive personal identifiers, and individual results were not shared with employers.

Participants self-reported their race or ethnicity. Reported height and weight were used to calculate body mass index (BMI); weight status categories were defined as underweight or normal (BMI <25), overweight (BMI ≥25 but <30), obese (BMI ≥30 but <40), and severely obese (BMI ≥40). Nonhospital healthcare workers (physicians, midlevel clinicians, nurse assistants, nurses, therapists, phlebotomists, imaging technicians, and dentists) were categorized as other direct patient care providers. Frequency of use of personal protective equipment (PPE) within 6 feet of a person with suspected or confirmed COVID-19 was categorized as all of the time, not all of the time (never or rarely, sometimes, and most of the time), and not applicable.

A total of 22,647 participants were included in our analysis (Appendix Figure 1). Percentage of SARS-CoV-2 IgG seropositivity and 95% CIs were calculated by selected characteristics and exposures. In subsequent analyses assessing seropositivity by frequency of aerosol-generating procedures and PPE use, we focused on occupations for which CDC-issued recommendations for PPE were in place: police (including traffic officers), medicolegal death investigators, firefighters, correctional staff, security guards, firefighters or medical first responders, paramedics, emergency medical technicians (EMTs), dispatchers (fire, emergency medical service [EMS], or police), and other direct patient-care providers.[3–6] We performed multivariable logistic regression with seropositivity as the outcome variable. Covariates were chosen a priori and checked for collinearity. Participants with implausible weight or height (n = 15) or missing housing status (n = 6) were excluded. We used SAS version 9.4 (SAS Institute, to perform statistical analyses. We considered 2-sided p values <0.05 to be statistically significant.

Figure 1.

Percentage of respondents who were seropositive for severe acute respiratory syndrome coronavirus 2 IgG, by occupation, in a study of first responders and public safety personnel, New York City, New York, USA, May 18–July 2, 2020. Numbers within bars indicate percentage of seropositive respondents. Error bars indicate 95% CIs. Other includes students or trainees, pharmacists, medical registrars, orderlies, dietitians, medical assistants, counselors, social workers, dietary services staff, environmental services staff, and participants who selected this category and were not reassigned to an existing category. Firefighters includes fire inspectors and fire marshals. Other direct patient care providers include dentists, diagnostic imaging technicians, midlevel clinicians, nurses, nurse assistants, occupational therapists, speech therapists, physical therapists, phlebotomists, physicians, respiratory therapists, and therapy aides. EMS, emergency medical service.