Introduction: Many vaccines have been developed to alleviate the risk of infection against the pandemic corona virus disease 2019 (COVID-19). Tooth and palatal development are influenced by acquired or inherited variables that may affect the general health. The effect of vaccines on organ development is an essential step for vaccine safety insurance.
Aim of the study: To detect the effect of different types of COVID-19 vaccines on tooth and palatal development..
Materials and Methods: Sixty female rats were arranged into four groups. Each group received either intramuscular injection of saline (Group I), mRNA vaccine (Group II), adenoviral vector vaccine (Group III), or inactivated vaccine (Group IV) at 21 and 14 days before mating and on the ninth day of gestation. The heads of the offspring “one day old" were collected, processed and stained by hematoxylin and eosin (H&E), Beta-catenin (β-catenin) and transforming growth factor–Beta2 (TGF-β2). The expressions of β-catenin and TGF-β2 in the developing tooth germ and palate were analyzed statistically.
Results: No histological or morphological changes in the developing teeth and palate were recorded in all studied groups except for the developing tooth germs in groups III and IV. All groups showed positive β-catenin and TGF-β2 immunoreactivity in the developing tooth germ and palate. Statistically, the vaccinated groups showed a significant difference in immunopositive area% to Group I, except β-catenin in Group II, and TGF-β2 of the developing palate in groups II and IV.
Conclusion: mRNA COVID-19 vaccine is safer than adenoviral vector and inactivated vaccines regarding tooth or/and palatal development