Longitudinal Follow-Up of the Immunity to SARS-CoV-2 in Health Care Workers in Argentina: Persistence of Humoral Response and Neutralizing Capacity after Sputnik V Vaccination

Abstract

Since December 2020, Argentina has begun a mass vaccination program. The first vaccine available in our country was Sputnik V, which has been approved for use in 71 countries with a total population of 4 billion people.

High-resolution kinetics and cellular determinants of antibody response to SARS-CoV-2 over two years after COVID-19 vaccination

“…Furthermore, the highest antibody responses and maintenance observed in response to infection underscore the importance of hybrid immunity, which needs to be taken into consideration by future vaccination strategies. These findings corroborate those of other studies showing increased humoral responses after the 3 rd booster dose 15,30,33,45 and when having hybrid immunity 6,23,45 . This increase in the magnitude and persistence of antibody responses after a booster by infection or vaccination may be attributed to immunization-induced cumulative affinity-enhancement of somatic hypermutations that differentiate into specific-memory B cells and long-lived bone marrow plasma cells 46 .…”

“…However, a decrease in immune protection has been documented across different vaccine platforms, resulting in a rise of breakthrough infections worldwide despite vaccine coverage. This has been exacerbated by the emergence of new SARS-CoV-2 Omicron variants of concern (VoCs) capable of escaping existing immunity more efficiently than Alpha, Beta, Gamma or Delta VoCs 5,6 .…”

“…The available data on hybrid immunity present conflicting findings. Several studies showed that hybrid immunity offers greater and broader protection against COVID-19, manifested by higher antibody titers and increased VoCs recognition, reduced risk of SARS-CoV-2 infection, and prevention of hospital admission and severe disease compared to natural or vaccineinduced immunity alone 6,[21][22][23] . However, other studies showed no differences in the effectiveness of natural, vaccine-induced, or hybrid immunity in terms of neutralizing antibodies or cellular immunity 22 .…”