Immune response to SARS-CoV-2 variants of concern in vaccinated individuals

 Matthias Becker, Alex Dulovic, Daniel Junker, Natalia Ruetalo, Philipp D. Kaiser, Yudi T. Pinilla, Constanze Heinzel, Julia Haering, Bjoern Traenkle, Teresa R. Wagner, Mirjam Layer, Martin Mehrlaender, Valbona Mirakaj, Jana Held, Hannes Planatscher, Katja Schenke-Layland, Gérard Krause, Monika Strengert, Tamam Bakchoul, Karina Althaus, Rolf Fendel, Andrea Kreidenweiss, Michael Koeppen, Ulrich Rothbauer, Michael Schindler, Nicole Schneiderhan-Marra

doi: https://doi.org/10.1101/2021.03.08.21252958

This article is a preprint and has not been certified by peer review [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

PDF: https://www.medrxiv.org/content/10.1101/2021.03.08.21252958v1.full.pdf

Abstract

The SARS-CoV-2 pandemic virus is consistently evolving with mutations within the receptor binding domain (RBD)1 being of particular concern2-4. To date, there is little research into protection offered following vaccination or infection against RBD mutants in emerging variants of concern (UK3, South African5, Mink6 and Southern California7). To investigate this, serum and saliva samples were obtained from groups of vaccinated (Pfizer BNT-162b28), infected and uninfected individuals. Antibody responses among groups, including salivary antibody response and antibody binding to RBD mutant strains were examined. The neutralization capacity of the antibody response against a patient-isolated South African variant was tested by viral neutralization tests and further verified by an ACE2 competition assay. We found that humoral responses in vaccinated individuals showed a robust response after the second dose. Interestingly, IgG antibodies were detected in large titers in the saliva of vaccinated subjects. Antibody responses showed considerable differences in binding to RBD mutants in emerging variants of concern. A substantial reduction in RBD binding and neutralization was detected for the South African variant. Taken together our data reinforces the importance of administering the second dose of Pfizer BNT-162b2 to acquire high levels of neutralizing antibodies. High antibody titers in saliva suggest that vaccinated individuals may have reduced transmission potential. Substantially reduced neutralization for the South African variant highlights importance of surveillance strategies to detect new variants and targeting these in future vaccines.

Competing Interest Statement

T.R.W., P.K., N.S.M. and U.R. are named as inventors on a patent application (EP 20 197 031.6) claiming the use of the described Nanobodies used in the NeutrobodyPlex for diagnosis and therapeutics filed by the Natural and Medical Sciences Institute. The other authors declare no competing interest.

Funding Statement

This work was financially supported by the State Ministry of Baden-Wuerttemberg for Economic Affairs, Labour and Housing Construction (grant numbers FKZ 3-4332.62-NMI-67 and FKZ 3-4332.62-NMI-68), the Ministerium for Wissenschaft und Kunst Baden-Wuerttemberg, the Initiative and Networking Fund of the Helmholtz Association of German Research Centres (grant number SO-96), the Deutsche Forschungsgemeinschaft (DFG-KO 3884/5-1) and the EU Horizon 2020 research and innovation programme (grant agreement number 101003480-CORESMA). The funders had no role in study design, data collection, data analysis or the decision to publish.

https://www.medrxiv.org/content/10.1101/2021.03.08.21252958v1