A Longitudinal Study in Tunisia to Assess the Anti-RBD IgG and IgA Responses Induced by Three Different COVID-19 Vaccine Platforms

Wafa Ben Hamouda; Mariem Hanachi; Sonia Ben Hamouda; Wafa Kammoun Rebai; Adel Gharbi; Amor Baccouche; Jihene Bettaieb; Oussema Souiai; Mohamed Ridha Barbouche; Koussay Dellagi; Melika Ben Ahmed; Chaouki Benabdessalem

doi:10.3390/tropicalmed9030061

A Longitudinal Study in Tunisia to Assess the Anti-RBD IgG and IgA Responses Induced by Three Different COVID-19 Vaccine Platforms

Trop Med Infect Dis. 2024 Mar 13;9(3):61. doi: 10.3390/tropicalmed9030061.

Authors

Wafa Ben Hamouda^{1

2}, Mariem Hanachi³, Sonia Ben Hamouda^{1

2}, Wafa Kammoun Rebai⁴, Adel Gharbi¹, Amor Baccouche¹, Jihene Bettaieb^{1

5}, Oussema Souiai³, Mohamed Ridha Barbouche^{1

6}, Koussay Dellagi⁷, Melika Ben Ahmed^{1

5}, Chaouki Benabdessalem¹

Affiliations

¹ Laboratory of Transmission, Control and Immunobiology of Infections, Institut Pasteur de Tunis, Tunis El Manar University, Tunis 1002, Tunisia.
² Department of Biological Sciences, Faculty of Sciences of Tunis, Tunis El Manar University, Tunis 1068, Tunisia.
³ Laboratory of Bioinformatics, Biomathematics and Biostatistics LR16IPT09, Institut Pasteur de Tunis, Tunis El Manar University, Tunis 1002, Tunisia.
⁴ Laboratory of Medical Parasitology, Biotechnologies and Biomolecules, Institut Pasteur de Tunis, Tunis El Manar University, Tunis 1002, Tunisia.
⁵ Faculty of Medicine of Tunis, Tunis El Manar University, Tunis 1068, Tunisia.
⁶ Department of Microbiology, Immunology, and Infectious Diseases, College of Medicine and Medical Sciences, Arabian Gulf University, Manama 329, Bahrain.
⁷ Pasteur Network, Institut Pasteur, 75724 Paris, France.

Abstract

Background: Vaccination constitutes the best strategy against COVID-19. In Tunisia, seven vaccines standing for the three main platforms, namely RNA, viral vector, and inactivated vaccines, have been used to vaccinate the population at a large scale. This study aimed to assess, in our setting, the kinetics of vaccine-induced anti-RBD IgG and IgA antibody responses.

Methods: Using in-house developed and validated ELISA assays, we measured anti-RBD IgG and IgA serum antibodies in 186 vaccinated workers at the Institut Pasteur de Tunis over 12 months.

Results: We showed that RNA vaccines were the most immunogenic vaccines, as compared to alum-adjuvanted inactivated and viral-vector vaccines, either in SARS-CoV-2-naïve or in SARS-CoV-2-experienced individuals. In addition to the IgG antibodies, the vaccination elicited RBD-specific IgAs. Vaccinated individuals with prior SARS-CoV-2 infection exhibited more robust IgG and IgA antibody responses, as compared to SARS-CoV-2-naïve individuals.

Conclusions: After following up for 12 months post-immunization, we concluded that the hierarchy between the platforms for anti-RBD antibody-titer dynamics was RNA vaccines, followed by viral-vector and alum-adjuvanted inactivated vaccines.

Keywords: COVID-19; IgA; IgG; RNA vaccines; inactivated vaccines; kinetics; viral vector vaccines.

Grants and funding

This research was funded by: The «URGENCE COVID-19» fundraising campaign of the Institut Pasteur (EASI project). This study was also funded by the French Ministry for Europe and Foreign Affairs (MEAE) via project REPAIR (International Pasteurian research program in response to coronavirus in Africa), coordinated by Institut Pasteur (Paris). The Ministry of Higher Education and Scientific Research in Tunisia through CIC-2016-IPT02 grant.