SARS-CoV-2 Infection, Vaccination and Antibody Response Trajectories in Adults: A Cohort Study in Catalonia

Abstract

Background: Heterogeneity of the population in relation to infection, COVID-19 vaccination and host characteristics is likely reflected in the underlying SARS-CoV-2 antibody responses.

Methods: We measured IgM, IgA and IgG levels against SARS-CoV-2 spike and nucleocapsid antigens in 1,076 adults of a cohort study in Catalonia between June-November 2020 and a second time between May-July 2021. Questionnaire data and electronic health records on vaccination and COVID-19 testing were available in both periods.

Findings: Antibody seroreversion occurred in 35.8% of the 64 participants infected almost a year ago and non-vaccinated, and was related to asymptomatic infection, age above 60 years and smoking. Among vaccinated, 2.1% did not present antibodies at the time of testing. In previously infected individuals, vaccination boosted the immune response and there was a slight but statistically significant increase in responses after a 2^nd compared to 1^st dose. Infected vaccinated participants had superior antibody levels across time compared to naïve vaccinated people. mRNA vaccines and, particularly the Spikevax, induced higher antibodies after 1^st and 2^nd doses compared to Vaxzevria or Janssen COVID-19 vaccines. In multivariable regression analyses, antibody responses after vaccination were predicted by type of vaccine, infection age, sex, smoking, mental and cardiovascular diseases.

Interpretation: Our data support that infected people would benefit from vaccination. Results also indicate that hybrid immunity results in superior antibody responses and infection-naïve people would need a booster dose earlier than previously infected people. Mental diseases are associated with less efficient response to vaccination.

Funding: This work was funded by Incentius a l’Avaluació de Centres CERCA (in_CERCA); EIT HEALTH BP2020-20873-Certify.Health.; Fundació Privada Daniel Bravo Andreu; PID2019-110810RB-I00 grant (Spanish Ministry of Science & Innovation). Rocio Rubio had the support of the Health Department, Catalan Government (PERIS SLT017/20/000224). E.P. was supported by a grant from the Junta de Andalucía/EU. ISGlobal acknowledges support from the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S). ISGlobal and IGTP receive support from the Generalitat de Catalunya through the CERCA Program. GCAT was funded by Acción de Dinamización del ISCIII-MINECO and the Ministry of Health of the Generalitat of Catalunya (ADE 10/00026); and have additional suport by the Agència de Gestió d’Ajuts Universitaris i de Recerca (AGAUR) (2017-SGR 529), National Grant PI18/01512 and VEIS project (001- P-001647) (co-funded by European Regional Development Fund (ERDF), “A way to build Europe”). This study was carried out using anonymized data provided by the Catalan Agency for Quality and Health Assessment, within the framework of the PADRIS Program.

Declaration of Interest: P. Santamaria is scientific founder of Parvus Therapeutics and has a financial interest in the company. The other authors declare no competing interests

Ethical Approval: All participants contacted had consented in the past to be re-contacted. Ethical approval was obtained from the Parc de Salut Mar Ethics Committee (CEIM-PS MAR, no. 2020/9307/I) and Hospital Universitari Germans Trias i Pujol Ethics Committee (CEI no.
PI-20-182). All participants provided informed consent.

Keywords: COVID-19 vaccines, SARS-CoV-2, antibody, kinetics, determinants, adults