Neutralizing antibodies from naturally infected individuals against SARS-CoV-2 Gamma and Delta variants in the Paraguayan population

• Published in: Journal of infection in developing countries Vol. 17; no. 10; pp. 1407 - 1412
• Main Authors: Samudio, Angélica, Sotelo, Pablo H, González-Maldonado, Pamela, Alfonso, Laura, Valiente-Echeverría, Fernando, Soto-Rifo, Ricardo, Langjahr, Patricia
• Format: Journal Article
• Language: English
• Published: 31.10.2023
• ISSN: 1972-2680; 1972-2680
• DOI: 10.3855/jidc.16955

Introduction: Severe Acute Respiratory Syndrome-Coronavirus-2 Virus (SARS-CoV-2) is responsible for Coronavirus Disease 2019 (COVID-19). A substantial number of SARS-CoV-2 infection cases have been reported during the pandemic, and vaccination coverage in some regions, particularly in developing countries, remains very low. SARS-CoV-2 variants of concern (VOCs) have also emerged as some of the most pressing public health issues. In this scenario, it is crucial to know whether COVID-19 convalescent antibodies have cross-neutralizing action against VOCs to contribute to the analysis of the future progress of the pandemic. Methodology: The plasma of individuals infected with SARS-CoV-2 from June to November 2020 in Paraguay (before the first recorded infections associated with VOCs in the country) was selected. Anti-spike antibodies were determined in plasma samples (n = 626) obtained from this convalescent and unvaccinated group. Using a pseudotyped virus neutralization assay, we then investigated the neutralizing response against D614G variant and Gamma, and Delta VOCs. Results: IgG antibodies against spike were detected in 85.6% of convalescent individuals. Samples from individuals previously infected by a non-VOC showed a 6.6- and 8.1-fold reduction in neutralizing capacity to the Gamma and Delta variants, respectively, when compared to the D614G variant. Conclusions: Our findings show that antibodies generated by non-VOC infection have reduced neutralizing capabilities against Gamma and Delta variants that appeared subsequently and might have implications for immunity strategies.