Immunoglobulin (Ig)A seropositivity against SARSCoV- 2 in healthcare workers in Israel, 4 April to 13 July 2020: An observational study

Yaniv Lustig, Carmit Cohen, Asaf Biber, Hanaa Jaber, Yaelilany Becker, Victoria Indenbaum, Sharon Amit, Michal Mandelboim, Ella Mendelson, Gili Regev-Yochay

Research output: Contribution to journalArticlepeer-review


Introduction: The COVID-19 pandemic has put healthcare workers (HCW) at significant risk. Presence of antibodies can confirm prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Aim: This study investigates the prevalence of IgA and IgG antibodies against SARS-CoV-2 in HCW. Methods: Performance of IgA and IgG antibody ELISA assays were initially evaluated in positive and negative SARS-CoV-2 serum samples. IgA and IgG antibodies against SARS-CoV-2 were measured in 428 asymptomatic HCW. We assessed the risk of two groups: HCW with high exposure risk outside work (HROW) residing in areas where COVID-19 was endemic (n = 162) and HCW with high exposure risk at work (HRAW) in a COVID-19 intensive care unit (ICU) (n = 97). Results: Sensitivities of 80% and 81.2% and specificities of 97.2% and 98% were observed for IgA and IgG antibodies, respectively. Of the 428 HCW, three were positive for IgG and 27 for IgA. Only 3/27 (11%) IgA-positive HCW had IgG antibodies compared with 50/62 (81%) in a group of previous SARS-CoV-2-PCR-positive individuals. Consecutive samples from IgA-positive HCW demonstrated IgA persistence 18-83 days in 12/20 samples and IgG seroconversion in 1/20 samples. IgA antibodies were present in 8.6% of HROW and 2% of HRAW. Conclusions: SARS-CoV-2 exposure may lead to asymptomatic transient IgA response without IgG seroconversion. The significance of these findings needs further study. Out of work exposure is a possible risk of SARS-CoV-2 infection in HCW and infection in HCW can be controlled if adequate protective equipment is implemented.

Original languageEnglish
Pages (from-to)1-17
Number of pages17
Issue number48
StatePublished - 2 Dec 2021
Externally publishedYes

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Epidemiology
  • Virology


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