Study On Immunogenicity And Immunological Persistence Of Inactivated Polio - Dolphin - Tetanus - Hepatitis B - Sabin Strain Inactivated Polio

Objective To primarily evaluate the immunogenicity and compatibility of different dosages and preparation process of combined DTaP-HepB-sIPV vaccines (Diphtheria, Tetanus, acellular Pertussis, Hepatitis B and Sabin inactivated Poliovirus combined vaccine).Methods This study designed four different experimental groups of DTaP-HepB-sIPV vaccine. Respectively, sIPV of group A was middle dose and contained adjuvant, sIPV of group B was middle dose with no adjuvant, sIPV of group C was low dose and contained adjuvant, sIPV of group D was low dose with no adjuvant. Control groups used corresponding components and a licensed vaccine. All groups of rats recieved primary immunization at 0,1,2,16 months. Blood samples were collected at 30 days after each dose, then determined the seroprotection rates and geometric mean titers (GMTs) of each antibody.Results After 3-dose primary schedule, each typed polio neutralizing antibody seroprotection rate of group A, B and C reached 100%. Type Ⅰ and type Ⅱ antibody seroprotection rates of group D reached 100%, with type Ⅲ antibody seroprotection rate of group D was only 80%. In the persistent study, each typed polio neutralizing antibody seroprotection rate of group A has been maintained at 100%, seroprotection rates of group B was 90%～100%, seroprotection rates of group C and D decreased to 55.6%～ 80%. After the booster, except group C, all other groups each typed polio virus neutralizing antibody seroprotection rates reached 100%. After booster, each typed polio virus neutralizing antibody GMT of experimental groups had 2 to 17-fold increase. Polio results showed that neutralizing antibody GMTs of A and C experimental groups could reach or exceed reference group. Furthermore, Type Ⅰ neutralizing antibody GMTs of B and D experimental groups were lower than corresponding control groups, and type Ⅱ and type Ⅲ neutralizing antibody GMTs of B and D experimental groups could reach even exceed the level of corresponding control groups. DTaP antibody test results showed that all seroprotection rates reached 100% after first dose, the differences of GMT between each experimental group were not statistically significant compared to DTaP control group (P>0.05). Hepatitis B antibody test results suggested that seroprotection rates of four experimental groups were between 40%～88.9%, but seroprotection rate of control group was 100%. The differences of Hepatitis B antibody between experimental groups and control group were not statistically significant (P>0.05).12 months after primary immunization, anti-HBs seroprotection of group B was 70%, hepatitis B control group was 55.6%, group A was 50%, group C was 42.9%, group D and the reference group were both 30%. After the booster, the seroprotection rates of Hepatitis B control group was 88.7%. Respectively, the seroprotection rate of group A was 66.7%, group B was 77.8%, group C was 50% and group D was 28.6%. The samples of licensed vaccine Y group were all negative.Conclusion Experimental combined vaccine of group A could induce high and stable humoral immune responses in rats.