IgA-Ab response to spike glycoprotein of SARS-CoV-2 in patients with COVID-19: A longitudinal study

Clin Chim Acta. 2020 Aug:507:164-166. doi: 10.1016/j.cca.2020.04.026. Epub 2020 Apr 25.


Validation studies of serological antibody tests must be properly designed for clinical, epidemiological and Public Health objectives such as confirmation of suspected COVID-19 cases, certification of seroconversion after infection, and epidemiological surveillance. We evaluated the kinetics of IgM, IgA and IgG SARS-CoV-2 antibodies in COVID-19 patients with confirmed (rRT-PCR) infection. We found that the IgA response appears and grows early, peaks at week 3, and it is stronger and more persistent than the IgM response. Further longitudinal investigations of virus-specific antibodies functions and of their protective efficacy over time are needed.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Viral / blood*
  • Betacoronavirus / isolation & purification*
  • COVID-19
  • Coronavirus Infections / blood*
  • Coronavirus Infections / diagnosis*
  • Female
  • Glycoproteins / blood*
  • Humans
  • Immunoglobulin A / blood*
  • Longitudinal Studies
  • Luminescent Measurements / methods
  • Male
  • Middle Aged
  • Pandemics
  • Pneumonia, Viral / blood*
  • Pneumonia, Viral / diagnosis*
  • Real-Time Polymerase Chain Reaction / methods
  • SARS-CoV-2
  • Young Adult


  • Antibodies, Viral
  • Glycoproteins
  • Immunoglobulin A