Common coronavirus infections don't generate effective antibodies
against SARS-CoV-2, study finds

Date:
March 30, 2022
Source:
American Chemical Society
Summary:
Researchers have shown that infections with two different common
human coronaviruses (HCoVs) don't generate antibodies that
effectively cross- react with SARS-CoV-2. So, prior infection
with HCoVs is unlikely to protect against COVID-19 or worsen a
SARS-CoV-2 infection through antibody-dependent enhancement (ADE),
the researchers say.



FULL STORY ========================================================================== Although SARS-CoV-2 has taken the world by storm, it's not the only
coronavirus that can infect humans. But unlike SARS-CoV-2, common
human coronaviruses (HCoVs) generally cause only mild disease. Now,
researchers reporting in ACS Infectious Diseaseshave shown that infections
with two different HCoVs don't generate antibodies that effectively
cross-react with SARS-CoV-2. So, prior infection with HCoVs is unlikely
to protect against COVID-19 or worsen a SARS- CoV-2 infection through antibody-dependent enhancement (ADE), the researchers say.


========================================================================== Because SARS-CoV-2 shares significant sequence similarity with its HCoV cousins, researchers have wondered if the immune system might recognize
the new coronavirus from prior bouts with HCoVs. This could re-activate
memory B cells, causing them to produce antibodies that helped the
person overcome previous HCoV infections, and might also help fight
COVID-19. On the other hand, if the antibodies against HCoVs recognize SARS-CoV-2, but not strongly enough to generate an immune response,
they could cause ADE. In this rare condition, sub- optimal antibodies
actually help some viruses attach to and enter host cells, making the
infection worse. Sebastien Fiedler, Tuomas Knowles and colleagues wanted
to compare the strength and concentration of antibodies against HCoVs
and SARS-CoV-2 in the sera of nine recovered COVID-19 patients and in
three pre-pandemic sera.

The researchers used a technique called microfluidic antibody-affinity profiling, which unlike the traditionally used enzyme-linked immunosorbent assay (known as ELISA), can measure both antibody affinity and
concentration independently. They found that all nine recovered COVID-19
sera samples contained moderate amounts of antibodies with high affinity
to the SARS-CoV- 2 spike protein. In contrast, none of the pre-pandemic
sera contained high- affinity antibodies for SARS-CoV-2. All 12 sera
contained low amounts of very high-affinity antibodies against two common HCoVs, indicating previous infections. Other experiments showed that these antibodies did not bind to SARS-CoV-2. The results suggest that there is
no significant cross-reactivity of antibodies against common HCoVs and SARS-CoV-2, and therefore, no expected protective or adverse effects of antibody cross-reactivity for these coronaviruses, the researchers say.

The authors acknowledge funding from the University of Zurich, the
University Hospital of Zurich, the NOMIS Foundation, the European Research Council, the National Institute for Health Research, the P.I. Terasaki
Scholar program, and the Biotechnology and Biological Sciences Research Council.


========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Viola Denninger, Catherine K. Xu, Georg Meisl, Alexey S. Morgunov,
Sebastian Fiedler, Alison Ilsley, Marc Emmenegger, Anisa Y. Malik,
Monika A. Piziorska, Matthias M. Schneider, Sean R. A. Devenish,
Vasilis Kosmoliaptsis, Adriano Aguzzi, Heike Fiegler, Tuomas
P. J. Knowles.

Microfluidic Antibody Affinity Profiling Reveals the Role
of Memory Reactivation and Cross-Reactivity in the Defense
Against SARS-CoV-2. ACS Infectious Diseases, 2022; DOI:
10.1021/acsinfecdis.1c00486 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220330103212.htm

--- up 4 weeks, 2 days, 10 hours, 51 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)