Emerging Microbes and Infections (Jan 2021)

Live virus neutralization testing in convalescent patients and subjects vaccinated against 19A, 20B, 20I/501Y.V1 and 20H/501Y.V2 isolates of SARS-CoV-2

  • Carla Saade,
  • Claudia Gonzalez,
  • Antonin Bal,
  • Martine Valette,
  • Kahina Saker,
  • Bruno Lina,
  • Laurence Josset,
  • Mary-Anne Trabaud,
  • Guillaume Thiery,
  • Elisabeth Botelho-Nevers,
  • Stéphane Paul,
  • Paul Verhoeven,
  • Thomas Bourlet,
  • Sylvie Pillet,
  • Florence Morfin,
  • Sophie Trouillet-Assant,
  • Bruno Pozzetto,
  • on behalf of COVID-SER study group

Journal volume & issue
Vol. 10, no. 1
pp. 1499 – 1502


Read online

SARS-CoV-2 mutations appeared recently and can lead to conformational changes in the spike protein and probably induce modifications in antigenicity. We assessed the neutralizing capacity of antibodies to prevent cell infection, using a live virus neutralization test with different strains [19A (initial one), 20B (B.1.1.241 lineage), 20I/501Y.V1 (B.1.1.7 lineage), and 20H/501Y.V2 (B.1.351 lineage)] in serum samples collected from different populations: two-dose vaccinated COVID-19-naive healthcare workers (HCWs; Pfizer-BioNTech BNT161b2), 6-months post mild COVID-19 HCWs, and critical COVID-19 patients. No significant difference was observed between the 20B and 19A isolates for HCWs with mild COVID-19 and critical patients. However, a significant decrease in neutralization ability was found for 20I/501Y.V1 in comparison with 19A isolate for critical patients and HCWs 6-months post infection. Concerning 20H/501Y.V2, all populations had a significant reduction in neutralizing antibody titers in comparison with the 19A isolate. Interestingly, a significant difference in neutralization capacity was observed for vaccinated HCWs between the two variants but not in the convalescent groups.