The candidate anti-tuberculosis mRNA vaccine immunogenicity and reactogenicity dependency on the animal’s sex and the vaccine dose

mRNA vaccines turned out to be highly effective in combating the COVID-19 pandemic and other viral infections. Despite extensive study of mRNA vaccines in the last five years, the issue of safety of their use is still relevant. The study aimed to assess immunogenicity of two anti-tuberculosis mRNA vaccine doses in female and male rats 2 and 4 weeks after vaccination. Hematological and biochemical parameters of blood were determined within the same timeframe. The dose-dependent nature of mRNA vaccine immunogenicity was confirmed in both females and males. Vaccination led to moderate lymphopenia and neutrophilia in male rats, as well as to apparent dose-dependent and sex-related changes in blood biochemistry parameters at various time points. The findings suggest moderate toxicity of the anti-tuberculosis mRNA vaccine and the importance of assessing its toxic effects at various time points in animals of both sexes.