An assessment, in mice, of the safety of the childhood immunization vaccines sourced from three south-eastern states of Nigeria

Abstract

Background: The current and general safety control tests for vaccines have been the use several animal tests. Vaccine is considered safe if it does not cause weight loss or death in laboratory animals at human dose, does not promote leukocytosis by a factor P10 and showed a Leukopenic toxicity value P80% of the Leukopenic toxicity of the control. The study sets to determine the safety of routine immunization vaccines from Anambra, Ebonyi and Enugu states of Nigeria and indirectly evaluate the efficiency of cold-chain facilities. Method: The study was designed to check the safety of the routine immunization vaccines to the hematopoietic system of mice and mice body weight changes after immunization. Results: Animal body weight changes test showed that the mice immunized with the vaccines increased in weight at days 3 and 7 post-immunization and exceeded 60% weight gain at day 7 post-immunization. None of the mice died during the observation period. Hematopoietic system toxicity tests showed that the vaccines are non- toxic. Conclusion: The vaccines were generally safe and non-toxic. The cold-chain systems in the States studied were efficient and had not compromised the safety of the vaccines.