ABSTRACT
To provide a basis for further optimization of the polio sequential immunization schedule, this study evaluated the effectiveness of booster immunization with one dose of bivalent oral poliovirus vaccine (bOPV) at 48 months of age after different primary polio immunization schedules. At 48 months of age, one dose of bOPV was administered, and their poliovirus types 1-3 (PV1, PV2, and PV3, respectively)-specific neutralizing antibody levels were determined. Participants found to be negative for any type of PV-specific neutralizing antibody at 24, 36, or 48 months of age were re-vaccinated with inactivated polio vaccine (IPV). The 439 subjects who received a bOPV booster immunization at the age of 48 months had lower PV2-specific antibody levels compared with those who received IPV. One dose of IPV during basic polio immunization induced the lowest PV2-specific antibody levels. On the basis of our findings, to ensure that no less than 70% of the vaccinated have protection efficiency, we recommend the following: if basic immunization was conducted with 1IPV + 2bOPV (especially Sabin strain-based IPV), a booster immunization with IPV is recommended at 36 months of age, whereas if basic immunization was conducted with 2IPV + 1bOPV, a booster immunization with IPV is recommended at 48 months of age. A sequential immunization schedule of 2IPV + 1bOPV + 1IPV can not only maintain high levels of antibody against PV1 and PV3 but also increases immunity to PV2 and induces early intestinal mucosal immunity, with relatively good safety. Thus, this may be the best sequential immunization schedule for polio in countries or regions at high risk for polio.
ABSTRACT
Objective To evaluate the antibody titer distributions after primary vaccination by different sequential schedules of Sabin strain-based inactivated poliovirus vaccine(sIPV) and bivalent oral attenuated live poliomyelitis vaccine against types 1 and 3 (bOPV) in Drug Candy(DC) form or liquid dosage form. Methods Eligible infants of 2 months old selected in Liuzhou were assigned randomly in a ratio of 1:1:1:1 to 4 groups as following: sIPV+2bOPV(DC), sIPV+2bOPV(liquid), 2sIPV+bOPV(DC), 2sIPV+bOPV(liquid), and were vaccinated at 0, 28, 56 days. Polio neutralizing antibody titers against poliovirus types 1, 2 and 3 were tested prior to Dose 1 and at 28 days after Dose 3. Results The antibody titer distribution for type 1 was statistically different between sIPV+2bOPV(DC) and sIPV+2bOPV(liquid) (Z=-2.589, P=0.010) while no significant differences were detected between the two groups for type 2(Z=-0.331, P=0.741) and type 3(Z=-1.556, P=0.120). There were no significant differences between 2sIPV +bOPV(DC) and 2sIPV+bOPV(liquid) for the distributions(All P>0.05) (type 1: Z=-1.249, P=0.212; type 2: Z=-1.658, P=0.097; type 3: Z=-1.436, P=0.151). In the same dosage forms with different sequential schedules, the antibody titer distributions were significantly different between 2 doses sIPV and 1 dose sIPV groups(All P<0.05)(sIPV+2bOPV(liquid) vs 2sIPV+bOPV(liquid): type 1: Z=-2.766, P=0.006; type 2: Z=-9.137, P<0.001; type 3: Z=-5.529, P<0.001. sIPV+2bOPV(DC) vs 2sIPV+bOPV(DC): type 1: Z=-3.748, P<0.001; type 2: Z=-7.660, P<0.001; type 3: Z=-6.030, P<0.001). Conclusions Different dosage forms have similar immune effects, so appropriate dosage forms should be selected for vaccination according to the effectiveness, characteristics of subjects and the population density. In the case of sufficient supply of sIPV, 2 doses sIPV sequential program should be the first choice to complete the primary immunization.
ABSTRACT
OBJECTIVE@#To investigate the epidemiological characteristics of mumps in mainland China from 2004 to 2018, and to provide data for the key population for prevention and control of mumps.@*METHODS@#The epidemiological characteristics of mumps were analyzed with reference to the data of the cases of mumps reported in the National Scientific Data Sharing Platform for Population and Health and Disease Prevention and Control Bureau of National Health Commission of the People's Republic of China. Descriptive epidemiology was used to analyze the epidemiological characteristics of mumps.@*RESULTS@#A total of 4 272 368 cases of mumps were reported in China during 2004-2018, with an average annual reported incidence rate of 21.44/100 000. A single dose of mumps-containing vaccine was added to the national Expanded Program of Immunization in 2008, but the annual incidence rate ranged from 12.84/100 000 to 35.59/100 000. The second dose of measles, mumps and rubella combined attenuated live vaccine was included in the routine immunization in Beijing, Tianjin and Shanghai, and then the average incidence rate of mumps reported in these three regions dropped to about 10/100 000. From 2004 to 2016, the population aged 3-14 years accounted for 81.16% of all patients with mumps. The children aged 6 years had the highest incidence rate of mumps during 2004-2013.@*CONCLUSIONS@#A single dose of mumps-containing vaccine has no obvious effect on the incidence rate of mumps. Children aged 6 years have the highest incidence rate of mumps. A booster dose of mumps-containing vaccine should be given to preschool children.
