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IntroductionThe humoral response to vaccines is the most used tool to evaluate the protection against SARS-CoV-2 infection. Dialysis patients are a high-risk population and have a reduced immune response to vaccination. ObjectiveTo assess the humoral response to homologous Gam-COVID-Vac (Sputnik V) and heterologous Sputnik V/mRNA-1273 (Moderna) vaccination in dialysis patients. MethodsSARS-CoV-2 anti-spike IgG (RBD) concentration was estimated 3-16 weeks after complete vaccination. Reactogenicity was evaluated until day 7 by patients s self-reported side events. Results107 participants were enrolled [n=84 homologous (SpV/SpV), n=23 heterologous (SpV/Mod)]. Median (IQR) age was 64 (50-75) years old and 79 (73.8%) were male. Additionally, 19 (22.6%) of the SpV/SpV and 4 (17.4%) of the SpV/Mod group had a prior confirmed SARS-CoV-2 infection (p=0.589). In the overall population, 103 patients reached seroconversion (96.3%). Anti-S-RBD IgG median titers (IQR) were higher in the heterologous [1222 (288-5680) BAU/mL] than in the homologous scheme [447 (100-1551) BAU/mL], p=0.022. In a linear model adjusted for age and gender, previous SARS-COV-2 infection (B: 1944.3; CI95: 1136.2-2753.4; p<0.001), and SpV/Mod vaccination scheme (B: 1241.5; CI95: 420.39-2062.6; p=0.003) were independently associated with anti-S-RBD levels. Finally, a higher frequency of adverse effects was associated with the heterologous scheme, although they were well tolerated by all individuals. ConclusionThe present study provides evidence that the homologous SpV/SpV and heterologous SpV/Mod schemes showed good efficacy and safety under dialysis conditions. These results could be useful for future vaccination strategies, especially aimed at this risk group.
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IntroductionGrowing data are demonstrating safety and immunogenicity of heterologous vaccination schemes against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. This strategy opens up the possibility of a shorter path towards the end of the pandemic. ObjectiveTo compare the homologous prime-boost vaccination scheme of Gam-COVID-Vac (Sputnik V, SpV) to its heterologous combination with mRNA-1273 (Moderna, Mod) vaccine. MethodsSARS-CoV-2 anti-spike (S)-receptor binding domain (RBD) IgG concentration was assessed three to seven weeks after complete vaccination. Reactogenicity was evaluated by declared side events and medical assistance required until day 7 post-boost. ResultsOf 190 participants enrolled, 105 received homologous SpV/SpV and the remaining heterologous SpV/Mod vaccination scheme, respectively. Median (interquartile range, IQR) age was 54 (37-63) years, 132 (69.5%) were female and 46 (24.2%) individuals had a prior confirmed COVID-19. Anti-S-RBD IgG median (IQR) titers were significantly higher for SpV/Mod [2511 (1476-3992) BAU/mL] than for SpV/SpV [582 (209-1609) BAU/mL, p<0.001] vaccination scheme. In a linear model adjusted for age, gender, time to the serological assay and time between doses, SpV/Mod [4.154 (6.585-615.554), p<0.001] and prior COVID [3.732 (8.641-202.010), p<0.001] were independently associated with higher anti-S-RBD IgG values. A higher frequency of mild-moderate adverse effects was associated with the heterologous scheme, although it was well tolerated by all individuals and no medical assistance was required. ConclusionThe heterologous SpV/Mod combination against SARS-CoV-2 is well tolerated and significantly increases humoral immune response as compared to the homologous SpV/SpV immunization.
