Cross-Variant Neutralizing Serum Activity after SARS-CoV-2 Breakthrough Infections

Emerg Infect Dis. 2022 May;28(5):1050-1052. doi: 10.3201/eid2805.220271. Epub 2022 Mar 8.


To determine neutralizing activity against the severe acute respiratory syndrome coronavirus 2 ancestral strain and 4 variants of concern, we tested serum from 30 persons with breakthrough infection after 2-dose vaccination. Cross-variant neutralizing activity was comparable to that after 3-dose vaccination. Shorter intervals between vaccination and breakthrough infection correlated with lower neutralizing titers.

Keywords: 2019 novel coronavirus disease; B cell; COVID-19; SARS-CoV-2; coronavirus disease; immunity; mRNA; neutralizing antibody; respiratory infections; severe acute respiratory syndrome coronavirus 2; vaccines; viruses; zoonoses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19*
  • Humans
  • SARS-CoV-2
  • Vaccination


  • Antibodies, Neutralizing
  • Antibodies, Viral