tetano
Editor, Senior Moderator
Clin Microbiol Infect
. 2021 Mar 2;S1198-743X(21)00102-6.
doi: 10.1016/j.cmi.2021.02.020. Online ahead of print.
SARS CoV-2 infections in health care workers with pre-existing T cell response: a prospective cohort study
Jos? L Casado[SUP] 1 [/SUP], Johannes H?emmerle[SUP] 2 [/SUP], Pilar Vizcarra[SUP] 3 [/SUP], Hector Velasco[SUP] 4 [/SUP], Tamara Velasco[SUP] 3 [/SUP], Marina Fernandez-Escribano[SUP] 2 [/SUP], Alejandro Vallejo[SUP] 5 [/SUP]
Affiliations
Abstract
Objective: T-cell responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are observed in unexposed individuals. We evaluated the impact of this pre-existing cellular response on incident SARS CoV-2 infections.
Methods: Follow up study of 38 seronegative health care workers (HCWs) with previous evaluation of CD8+ and CD4+ T-cell response after stimulation with SARS-CoV-2 structural proteins. Infection was considered in presence of a positive reverse transcription (RT)-PCR test and/or confirmed seroconversion.
Results: Twenty of the 38 HCWs included (53%) had a previous specific CD8+ T cell response to peptides encompassing the spike (S) protein in 13 (34%), the membrane (M, 17, 45%), or/and the nucleocapsid (N, 3, 8%). During a follow up of 189 days (interquartile range, IQR, 172 to 195), 11 (29%) HCWs had a RT-PCR positive test (n=9) or seroconverted (n=2). Median duration of symptoms was 2 days (IQR, 0-7), and time to negative RT-PCR was 9 days (IQR, 4-10). Notably, six incident infections (55%) occurred in HCWs with pre-existing T-cell response (30% of those with cellular response), who showed a significant lower duration of symptoms (three were asymptomatic). Three of the six HCWs having previous T-cell response continued testing seronegative. All the infected patient developed a robust T-cell response to different structural SARS-CoV-2 proteins, especially to protein S (91%).
Conclusion: Pre-existing T-cell response does not seems to reduce incident SARS-CoV-2 infections, but it may contribute to asymptomatic or mild disease, rapid viral clearance and differences in seroconversion.
Keywords: COVID-19; Cross-reactivity; Healthcare workers; Immune response; SARS-CoV-2; T-cell response.
. 2021 Mar 2;S1198-743X(21)00102-6.
doi: 10.1016/j.cmi.2021.02.020. Online ahead of print.
SARS CoV-2 infections in health care workers with pre-existing T cell response: a prospective cohort study
Jos? L Casado[SUP] 1 [/SUP], Johannes H?emmerle[SUP] 2 [/SUP], Pilar Vizcarra[SUP] 3 [/SUP], Hector Velasco[SUP] 4 [/SUP], Tamara Velasco[SUP] 3 [/SUP], Marina Fernandez-Escribano[SUP] 2 [/SUP], Alejandro Vallejo[SUP] 5 [/SUP]
Affiliations
- PMID: 33667629
- PMCID: PMC7923873
- DOI: 10.1016/j.cmi.2021.02.020
Abstract
Objective: T-cell responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are observed in unexposed individuals. We evaluated the impact of this pre-existing cellular response on incident SARS CoV-2 infections.
Methods: Follow up study of 38 seronegative health care workers (HCWs) with previous evaluation of CD8+ and CD4+ T-cell response after stimulation with SARS-CoV-2 structural proteins. Infection was considered in presence of a positive reverse transcription (RT)-PCR test and/or confirmed seroconversion.
Results: Twenty of the 38 HCWs included (53%) had a previous specific CD8+ T cell response to peptides encompassing the spike (S) protein in 13 (34%), the membrane (M, 17, 45%), or/and the nucleocapsid (N, 3, 8%). During a follow up of 189 days (interquartile range, IQR, 172 to 195), 11 (29%) HCWs had a RT-PCR positive test (n=9) or seroconverted (n=2). Median duration of symptoms was 2 days (IQR, 0-7), and time to negative RT-PCR was 9 days (IQR, 4-10). Notably, six incident infections (55%) occurred in HCWs with pre-existing T-cell response (30% of those with cellular response), who showed a significant lower duration of symptoms (three were asymptomatic). Three of the six HCWs having previous T-cell response continued testing seronegative. All the infected patient developed a robust T-cell response to different structural SARS-CoV-2 proteins, especially to protein S (91%).
Conclusion: Pre-existing T-cell response does not seems to reduce incident SARS-CoV-2 infections, but it may contribute to asymptomatic or mild disease, rapid viral clearance and differences in seroconversion.
Keywords: COVID-19; Cross-reactivity; Healthcare workers; Immune response; SARS-CoV-2; T-cell response.