Heterologous Ad26.COV2.S Prime and mRNA-Based Boost COVID-19 Vaccination Regimens: The SWITCH Trial Protocol.

The prime and boost vaccines are administered in a so-called "homologous" vaccination regimen, meaning that both given vaccinations are identical. SARS-CoV-2, COVID-19, randomized clinical trial, Ad26.Cov2.S, BNT162.b2, mRNA1273, Homologous vaccination regimen, Heterologous vaccine regimen Keywords: SARS-CoV-2; COVID-19; Homologous vaccination regimen; Heterologous vaccine regimen; randomized clinical trial; Ad26.Cov2.S; BNT162.b2; mRNA1273 EN SARS-CoV-2 COVID-19 Homologous vaccination regimen Heterologous vaccine regimen randomized clinical trial Ad26.Cov2.S BNT162.b2 mRNA1273 1 4 4 09/29/21 20210924 NES 210924 Currently, four COVID-19 vaccines are authorized for use in the European Union by the European Medicines Agency (EMA), i.e., Ad26.COV2.S ([1]), ChAdOx1 nCoV-19 ([2]), mRNA1273 ([3]), and BNT162b2 ([4]). [Extracted from the article]