tetano
Editor, Senior Moderator
MMWR Morb Mortal Wkly Rep
. 2020 Nov 27;69(47):1762-1766.
doi: 10.15585/mmwr.mm6947a2.
Decline in SARS-CoV-2 Antibodies After Mild Infection Among Frontline Health Care Personnel in a Multistate Hospital Network - 12 States, April-August 2020
Wesley H Self, Mark W Tenforde, William B Stubblefield, Leora R Feldstein, Jay S Steingrub, Nathan I Shapiro, Adit A Ginde, Matthew E Prekker, Samuel M Brown, Ithan D Peltan, Michelle N Gong, Michael S Aboodi, Akram Khan, Matthew C Exline, D Clark Files, Kevin W Gibbs, Christopher J Lindsell, Todd W Rice, Ian D Jones, Natasha Halasa, H Keipp Talbot, Carlos G Grijalva, Jonathan D Casey, David N Hager, Nida Qadir, Daniel J Henning, Melissa M Coughlin, Jarad Schiffer, Vera Semenova, Han Li, Natalie J Thornburg, Manish M Patel, CDC COVID-19 Response Team; IVY Network
Collaborators, Affiliations
Abstract
Most persons infected with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), develop virus-specific antibodies within several weeks, but antibody titers might decline over time. Understanding the timeline of antibody decline is important for interpreting SARS-CoV-2 serology results. Serum specimens were collected from a convenience sample of frontline health care personnel at 13 hospitals and tested for antibodies to SARS-CoV-2 during April 3-June 19, 2020, and again approximately 60 days later to assess this timeline. The percentage of participants who experienced seroreversion, defined as an antibody signal-to-threshold ratio >1.0 at baseline and <1.0 at the follow-up visit, was assessed. Overall, 194 (6.0%) of 3,248 participants had detectable antibodies to SARS-CoV-2 at baseline (1). Upon repeat testing approximately 60 days later (range = 50-91 days), 146 (93.6%) of 156 participants experienced a decline in antibody response indicated by a lower signal-to-threshold ratio at the follow-up visit, compared with the baseline visit, and 44 (28.2%) experienced seroreversion. Participants with higher initial antibody responses were more likely to have antibodies detected at the follow-up test than were those who had a lower initial antibody response. Whether decay in these antibodies increases risk for reinfection and disease remains unanswered. However, these results suggest that serology testing at a single time point is likely to underestimate the number of persons with previous SARS-CoV-2 infection, and a negative serologic test result might not reliably exclude prior infection.
. 2020 Nov 27;69(47):1762-1766.
doi: 10.15585/mmwr.mm6947a2.
Decline in SARS-CoV-2 Antibodies After Mild Infection Among Frontline Health Care Personnel in a Multistate Hospital Network - 12 States, April-August 2020
Wesley H Self, Mark W Tenforde, William B Stubblefield, Leora R Feldstein, Jay S Steingrub, Nathan I Shapiro, Adit A Ginde, Matthew E Prekker, Samuel M Brown, Ithan D Peltan, Michelle N Gong, Michael S Aboodi, Akram Khan, Matthew C Exline, D Clark Files, Kevin W Gibbs, Christopher J Lindsell, Todd W Rice, Ian D Jones, Natasha Halasa, H Keipp Talbot, Carlos G Grijalva, Jonathan D Casey, David N Hager, Nida Qadir, Daniel J Henning, Melissa M Coughlin, Jarad Schiffer, Vera Semenova, Han Li, Natalie J Thornburg, Manish M Patel, CDC COVID-19 Response Team; IVY Network
Collaborators, Affiliations
- PMID: 33237893
- DOI: 10.15585/mmwr.mm6947a2
Abstract
Most persons infected with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), develop virus-specific antibodies within several weeks, but antibody titers might decline over time. Understanding the timeline of antibody decline is important for interpreting SARS-CoV-2 serology results. Serum specimens were collected from a convenience sample of frontline health care personnel at 13 hospitals and tested for antibodies to SARS-CoV-2 during April 3-June 19, 2020, and again approximately 60 days later to assess this timeline. The percentage of participants who experienced seroreversion, defined as an antibody signal-to-threshold ratio >1.0 at baseline and <1.0 at the follow-up visit, was assessed. Overall, 194 (6.0%) of 3,248 participants had detectable antibodies to SARS-CoV-2 at baseline (1). Upon repeat testing approximately 60 days later (range = 50-91 days), 146 (93.6%) of 156 participants experienced a decline in antibody response indicated by a lower signal-to-threshold ratio at the follow-up visit, compared with the baseline visit, and 44 (28.2%) experienced seroreversion. Participants with higher initial antibody responses were more likely to have antibodies detected at the follow-up test than were those who had a lower initial antibody response. Whether decay in these antibodies increases risk for reinfection and disease remains unanswered. However, these results suggest that serology testing at a single time point is likely to underestimate the number of persons with previous SARS-CoV-2 infection, and a negative serologic test result might not reliably exclude prior infection.