[Safety analysis of 12 241 infants inoculated in three sites of diphtheria, tetanus, acellular pertussis and haemophilus influenzae type b combined vaccine in Chaoyang District of Beijing]

Objective: To observe the adverse reactions of Diphtheria, Tetanus, Acellular Pertussis and Haemophilus Influenzae Type b Combined Vaccine conjugate vaccine at the anterolateral thigh muscle, upper arm deltoid muscle and upper gluteal region. Methods: A total of 12 241 infants who were voluntarily vaccinated DTaP-Hib from April 2015 to April 2019 in Beijing were selected for the study. DTaP-Hib vaccine is recommended for 3, 4, 5 months of age for basic immunization and 18 to 24 months of age to strengthen immunization. Subjects were divided into the groups of lateral thigh muscle, the upper arm deltoid and upper gluteal region according to the actual inoculation sites. Adverse reactions were collected within 30 minutes and 7 days after each does of vaccination at different sites and compared between three groups. The incidence of adverse reactions at the three different inoculation sites was compared by Chi-square test. Results: A total of 12 241 infants and toddlers received combined DTaP-Hib and 35 027 doses of DTaP-Hib were investigated. The number and of lateral thigh muscles, upper arm deltoids and gluteal muscles were 3 461 infants and 11 129 doses, 2 659 infants and 7 957 doses, 6 121 infants and 15 941 doses respectively. A total of 2 489 adverse reactions occurred. The incidence of adverse reactions was 7.11%. The incidence of adverse reactions in deltoid muscle of upper arm was 9.69%（771 doses）, which was higher than that in gluteal muscle (7.58%, 1 211 doses) and anterolateral muscle of thigh (4.56%, 507 doses). The incidence of mild, moderate and severe adverse reactions in the upper arm deltoid group were higher than those in the other two groups. The incidence rates were 4.85% (386 doses), 3.77% (300 doses) and 1.07% (85 doses) respectively. The differences between groups were statistically significant（P<0.001）. The total adverse reactions of the three doses of basic immunization and the fourth dose of enhanced immunization had the same trend in different parts. The incidence of adverse reactions was in the order of the upper arm deltoid injection, upper gluteal injection and lateral thigh muscle injection from high to low. The differences were statistically significant (P<0.001). Conclusion: The incidence of adverse reactions of DTaP-Hib vaccination in three different sites was low, which confirmed that the DTaP-Hib vaccination got expected safety regardless of the sites of inoculation. The lateral femoral muscle group had the lowest incidence of adverse reactions, hence it should be preferred as the inoculation site of DTaP-Hib vaccination.