SARS-CoV-2–Specific Neutralizing Antibody Responses in Norwegian Health Care Workers After the First Wave of COVID-19 Pandemic: A Prospective Cohort Study
Trieu, Mai Chi; Bansal, Amit; Madsen, Anders; Zhou, Fan; Sævik, Marianne; Vahokoski, Juha; Brokstad, Karl Albert; Krammer, Florian; Tøndel, Camilla; Mohn, Kristin Greve-Isdahl; Blomberg, Bjørn; Langeland, Nina; Cox, Rebecca Jane
Journal article, Peer reviewed
Published version
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https://hdl.handle.net/11250/2755253Utgivelsesdato
2021Metadata
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- Department of Clinical Science [2430]
- Registrations from Cristin [10729]
Sammendrag
Background
During the coronavirus disease 2019 (COVID-19) pandemic, many countries experienced infection in health care workers (HCW) due to overburdened health care systems. Whether infected HCW acquire protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear.
Methods
In a Norwegian prospective cohort study, we enrolled 607 HCW before and after the first COVID-19 wave. Exposure history, COVID-19–like symptoms, and serum samples were collected. SARS-CoV-2–specific antibodies were characterized by spike-protein IgG/IgM/IgA enzyme-linked immunosorbent and live-virus neutralization assays.
Results
Spike-specific IgG/IgM/IgA antibodies increased after the first wave in HCW with, but not in HCW without, COVID-19 patient exposure. Thirty-two HCW (5.3%) had spike-specific antibodies (11 seroconverted with ≥4-fold increase, 21 were seropositive at baseline). Neutralizing antibodies were found in 11 HCW that seroconverted, of whom 4 (36.4%) were asymptomatic. Ninety-seven HCW were tested by reverse transcriptase polymerase chain reaction (RT-PCR) during follow-up; 8 were positive (7 seroconverted, 1 had undetectable antibodies).
Conclusions
We found increases in SARS-CoV-2 neutralizing antibodies in infected HCW, especially after COVID-19 patient exposure. Our data show a low number of SARS-CoV-2–seropositive HCW in a low-prevalence setting; however, the proportion of seropositivity was higher than RT-PCR positivity, highlighting the importance of antibody testing.