Infection with Covid-19 has been associated with some medical complications namely diabetes, thrombosis, and hepatic and renal dysfunction among others. This situation has created some concern about the use of relevant vaccines which might cause similar complications. In that regard, we planned to evaluate the impact of two of the relevant vaccines namely ChAdOx1-S and BBIBP-CorV on some of the blood biochemical factors and also on liver and kidneys functions following the immunization of healthy and streptozotocin-induced diabetic rats. Evaluation of the level of neutralizing antibody among the rats indicated that immunization with ChAdOx1-S induced a higher level of neutralizing antibody among both the healthy and diabetic rats compared to the BBIBP-CorV vaccine. Furthermore, the neutralizing antibody levels against both types of vaccines were significantly lower in diabetic rats than in healthy ones. On the other hand, no alterations were observed in the rats’ sera biochemical factors, coagulation values and histopathological images of the liver and kidneys. Altogether these data besides of confirming the effectiveness of both vaccines, indicate that both vaccines have no hazardous side effects on rats and probably humans though clinical investigations are required to validate our present data.