This is a summary, written by members of the CITF Secretariat, of:

Asamoah-Boaheng M, Grunau B, Karim ME, Jassem AN, Bolster J, Marquez AC, Scheuermeyer FX, Goldfarb DM. Are higher antibody levels against seasonal human coronaviruses associated with a more robust humoral immune response after SARS-CoV-2 vaccination? Front Immunol. 2022 Sep 8;13:954093. doi:

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study, published in Frontiers Immunology, highlights the interplay between SARS-CoV-2 vaccination, pre-existing immunity to common human endemic coronaviruses (HCoVs), and the resulting immune response to SARS-CoV-2. Specifically, higher baseline HCoV-229E and HCoV-NL63 anti-spike IgG antibody levels were associated with increased SARS-COV-2 anti-spike IgG antibody levels.  This study was led by Drs. Michael Asamoah-Boaheng, David Goldfarb, and Brian Grunau (University of British Columbia) in collaboration with Dr. Agatha Jassem (BC Centre for Disease Control).

Among a cohort of vaccinated and unvaccinated paramedics, the authors investigated the cross-reactivityAn antibody directed against one specific antigen is successful in binding with another, different antigen between anti-spike IgG antibodies against SARS-CoV-2 and four common endemic coronaviruses (the alpha coronaviruses HCoV-229E and HCoV-NL63, and the beta coronaviruses, HCoV-HKU1 and HCoV-OC43). The authors first compared samples from vaccinated to unvaccinated participants to determine which HCoV antibody levels were affected by vaccination. They modelled the association between anti-spike IgG levels for each strain of HCoV and SARS-CoV-2. Among those HCoVs for which antibodies were affected by vaccination, the authors explored the correlation between post-vaccination HCoV and SARS-CoV-2 antibody levels.

Key findings:

  • Among participants without previous COVID-19, there were significant differences between COVID-19-vaccinated and unvaccinated participants in anti-spike antibodies to HCoV-HKU1 and HCoV-OC43.
  • However, levels of anti-spike antibodies for HCoV-229E and HCoV-NL63 were similar, suggesting that vaccination did not affect these baseline values.
  • This suggests that antibodies generated by the SARS-CoV-2 vaccine react with HCoV spike from beta coronaviruses that are more closely related to SARS-CoV-2.
  • Among vaccinated COVID-19 participants, higher baseline levels of HCoV-229E and HCoV-NL63 anti-spike IgG antibodies were associated with increased SARS-COV-2 anti-spike IgG antibodies. This implies that pre-existing immunity to these common coronaviruses may enhance the immune response elicited by SARS-CoV-2 vaccination.

Overall, the study shows that pre-existing immunity to specific coronaviruses may bolster immune responses to the SARS-CoV-2 vaccine. These findings have important implications because common coronaviruses are resuming circulation with the lifting of nonpharmaceutical interventions, such as masks and handwashing. Understanding the impacts that re-exposure to these viruses will have on SARS-CoV-2 immunity could help inform public health strategies and vaccination efforts.

The study population consisted of 1,510 participants from the COVID-19 Occupational Risks, Seroprevalence, and Immunity among Paramedics in Canada (CORSIP) observational cohort study, which is a longitudinal study examining the workplace risks and seroprevalence of SARS-CoV-2 exposure among paramedics (aged 19 and older) working in British Columbia, Alberta, Ontario, Saskatchewan, and Manitoba. Participants provided blood samples upon enrollment, questionnaire data, and results of all SARS-CoV-2 polymerase chain reaction (PCR) and rapid antigen tests and vaccinations.