Immunogenicity and reactogenicity of heterologous immunization schedules using Sputnik V, ChAdOx1-S, BBIBP-CorV, Ad5-nCoV and mRNA-1273

In Argentina, a number of different vaccine platforms are being used, including the non-replicating adenovirus vaccines ChAdOx1-S, Ad5-nCoV, and Sputnik V; the mRNA vaccines BNT162b2 and mRNA-1273; and the inactivated SARS-CoV-2 vaccine BBIBP-CorV. Although data are available about mRNA and ChAdOx1 vaccines combination, very limited information has been reported combining these platforms with other vaccines widely used in developing countries, such as BBIBP-CorV and Sputnik V. We assessed the immunogenicity and reactogenicity of 15 vaccine combinations in a cohort of 1314 participants.

The antibody response was evaluated by determining IgG antibodies anti-spike and serum neutralizing titers. We observed that a number of heterologous vaccine combinations are equivalent or superior to the homologous schemes. For all the cohorts analyzed, the highest antibody response was induced by mRNA-1273 as second dose.