Immunogenicity of SPUTNIK V, BBIBP-CorV and ChAdOx-1S Vaccines in naïve and previously infected individuals from Tandil, Argentina.

GUTIÉRREZ S.E.; RIVERO M.A.; RODRÍGUEZ M.G.; ESTEIN S.M.

Mar del Plata

Otro; Reunión Conjunta SAIC, SAI & FAIC, SAFIS 2022. LXVII Reunión anual de la Sociedad Argentina de Investigación Clínica (SAIC), LXX Reunión anual de la Sociedad Argentina de Inmunología (SAI) & 3er Congreso Franco-Argentino de Inmunología (FAIC).; 2022

SAI

826. (562) IMMUNOGENICITY OF SPUTNIK V, BBIBP-CorV andChAdOx-1S VACCINES IN NAÏVE AND PREVIOUSLY INFECTEDINDIVIDUALS FROM TANDIL, ARGENTINASilvina Elena Gutiérrez1,2, Mariana Rivero1,2, Marcelo Rodríguez1,Silvia Marcela Estein1,2Departamento de Salud Animal y Medicina Preventiva, Facultadde Ciencias Veterinarias, Universidad Nacional delCentro de la Provincia de Buenos Aires (UNCPBA); Centrode Investigación Veterinaria de Tandil (UNCPBA-CICPBA-CONICET), Tandil, Buenos Aires, Argentina.Mass vaccination has been the key element in controlling theCOVID-19 pandemic. Vaccination in Tandil began in January 2021for health care workers, which mainly received Sputnik V (SpV). Theinactivated vaccine from Sinopharm (Si) and the ChAdOs-1S vaccinefrom AstraZeneca (AZ) were available since March 2021. Weaimed to measure and compare anti-SARS CoV-2 spike (S) antibodiesin naïve and seropositive individuals after receiving first andsecond dose of different vaccines. A total of 141 individuals wererecruited between January and August 2021. Serum samples wereobtained before vaccination and after each vaccine dose. Specificanti-S antibodies were quantified using the COVIDAR IgG ELISA.Results were log transformed and a repeated measures ANOVAwas adjusted. Seventy-one individuals had detectable anti-S antibodiesdue to previous infection while 70 were seronegative beforereceiving the first dose (initial status). Fifty-four from 71 (76%) of theinitially seronegative participants seroconverted after the first dose.All but one of the non-seroconverters received the Si vaccine. Afterthe second dose 95.8% of the participants seroconverted. Differenceswere observed depending on the initial status, type of vaccineand number of doses received (p= 0.0017). The titer of antibodieselicited against the first dose was influenced by the initial statusof the individual for the 3 vaccines. After the vaccination schemewas completed, there were also differences in the level of specificantibodies achieved depending on the initial status in those whoreceived the adenovirus vectored vaccines. Both in naïve and sensitizedparticipants SpV and AZ induced higher levels of antibodiescompared to Si (p> 0.05). Sinopharm resulted the less immunogenicvaccine. This result may be due to the interval between shots, whichwas 47 days mean, instead of the recommended 21-30 days. Therefore,individuals vaccinated with 2 doses of Si may be benefited froman heterologous booster.