[Observation on safety of sequential vaccination schedule of different strain inactivated poliovirus vaccines].

Objective: To evaluate the safety of population based sequential vaccination schedule of inactivated poliovirus vaccines prepared with different strains. Methods: This randomized, parallel-group controlled trial was conducted from March, 2017 to May, 2018, in Shanghai. Adverse reaction data of Sabin strain inactivated polio vaccine (sIPV), wild strains inactivated polio vaccines (wIPV) and bivalent types Ⅰ and Ⅲ oral poliomyelitis vaccine (bOPV) were systematically collected through active observation in 1 917 infants in Shanghai after the vaccination at 2, 3, 4 months old. The eligible infants aged 2 months were divided into 4 groups: ①sIPV+sIPV+bOPV group; ②sIPV+wIPV+bOPV group; ③wIPV+sIPV+bOPV group; ④wIPV+wIPV+bOPV group. Results: The incidence of adverse reaction 30 days later after 3 basic dose vaccinations was 16.79% (946/5 633). No serious adverse reaction was reported. Local and systemic reactions were mainly mild. Common local reactions were pain, erythema, cutaneous nodule, etc.; and common systemic reactions were abnormal crying, drowsiness, diarrhea and appetite lost, etc.. The incidence of local reactions 30 days later after 3 basic dose vaccinations was 1.65% (93/5 633), and the incidence rates of grade 1-3 reactions were1.26% (71/5 633), 0.21% (12/5 633) and 0.20% (11/5 633) respectively. The incidence rate of systemic reactions 30 days later after 3 basic vaccinations was 15.14% (853/5 633), and the incidence rates of grade 1-3 reactions were 11.33% (638/5 633), 3.18% (179/5 633) and 0.64% (36/5 633) respectively. There were no significant differences in the rate of grade 3 reaction among different groups (χ(2)=4.17, P=0.24). Conclusions: No severe adverse reactions related to sequential vaccination of different strain inactivated polio vaccines were observed, most of reactions were mild and all of them were cured. It is safe to use sIPV and wIPV simultaneously or alternately for childhood sequential vaccination.

Observation on safety of sequential vaccination schedule of different strain inactivated poliovirus vaccines / 中华流行病学杂志

Objective@#To evaluate the safety of population based sequential vaccination schedule of inactivated poliovirus vaccines prepared with different strains.@*Methods@#This randomized, parallel-group controlled trial was conducted from March, 2017 to May, 2018, in Shanghai. Adverse reaction data of Sabin strain inactivated polio vaccine (sIPV), wild strains inactivated polio vaccines (wIPV) and bivalent types Ⅰ and Ⅲ oral poliomyelitis vaccine (bOPV) were systematically collected through active observation in 1 917 infants in Shanghai after the vaccination at 2, 3, 4 months old. The eligible infants aged 2 months were divided into 4 groups: ①sIPV+sIPV+bOPV group; ②sIPV+wIPV+bOPV group; ③wIPV+sIPV+bOPV group; ④wIPV+wIPV+bOPV group.@*Results@#The incidence of adverse reaction 30 days later after 3 basic dose vaccinations was 16.79% (946/5 633). No serious adverse reaction was reported. Local and systemic reactions were mainly mild. Common local reactions were pain, erythema, cutaneous nodule, etc.; and common systemic reactions were abnormal crying, drowsiness, diarrhea and appetite lost, etc.. The incidence of local reactions 30 days later after 3 basic dose vaccinations was 1.65% (93/5 633), and the incidence rates of grade 1-3 reactions were1.26% (71/5 633), 0.21% (12/5 633) and 0.20% (11/5 633) respectively. The incidence rate of systemic reactions 30 days later after 3 basic vaccinations was 15.14% (853/5 633), and the incidence rates of grade 1-3 reactions were 11.33% (638/5 633), 3.18% (179/5 633) and 0.64% (36/5 633) respectively. There were no significant differences in the rate of grade 3 reaction among different groups (χ2=4.17, P=0.24).@*Conclusions@#No severe adverse reactions related to sequential vaccination of different strain inactivated polio vaccines were observed, most of reactions were mild and all of them were cured. It is safe to use sIPV and wIPV simultaneously or alternately for childhood sequential vaccination.

Comparing the antibody titers of sequential program of Sabin strain-based inactivated poliovirus vaccine followed by bivalent types 1 and 3 oral poliovirus vaccine in different dosage forms / 中华疾病控制杂志

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.

Immunogenicity of sequential inactivated and oral poliovirus vaccines (OPV) versus inactivated poliovirus vaccine (IPV) alone in healthy infants: A systematic review and meta-analysis.

BACKGROUND: The emergence of vaccine-associated paralytic poliomyelitis has become an ongoing burden of poliomyelitis. During this special period from OPV to IPV-only immunization schedule, we did a meta-analysis to compare the immunogenicity of sequential IPV and OPV versus IPV alone in healthy infants. METHODS: This systematic review and meta-analysis was registered at international prospective register of systematic reviews (PROSPERO), and the number was CRD42017054889. We performed it as described. RESULTS: Finally, 6 articles were qualified for our review. The results showed that seroconversion rates against all 3 serotype polioviruses were non-inferior and Geometric mean antibody titers (GMTs) were superior in sequential schedules compared with IPV-only schedule. Thus, the sequential vaccination schedules could induce a stronger immunogenicity. CONCLUSIONS: To decrease vaccine-associated and vaccine-derived poliomyelitis, it is a reasonable option to select sequential schedules during this special transition from OPV to IPV-only immunization schedule, which coincides with the current WHO recommendations.

Coverage estimates and patterns of inactivated poliovirus vaccine (IPV) use prior to and during the polio eradication endgame, Jinan City, China, 2010-2015.

BACKGROUND: Use of inactivated poliovirus vaccine (IPV) in Jinan during the polio eradication endgame has not been previously documented. Two IPV-containing vaccines were made available as an option for Jinan parents in 2009. We describe coverage levels and patterns of use of IPV over time using data from the Jinan Childhood Immunization Information Management System (JNCIIMS). METHODS: Children born between January 2010 and December 2014 who were registered in JNCIIMS were included in this study. Vaccination records were obtained from JNCIIMS on April 30, 2015. JNCIIMS distinguishes among available poliovirus vaccines; doses administered data were used to describe IPV usage over time. We identified the polio vaccination sequences used by children in the 2012 and 2013 birth cohorts. Coverage estimates were analyzed by birth cohort and migration status. We developed 3 categories for analysis: "resident child," "migrant child" and "other child" according to migration status. RESULTS: In total, 12,354 (11.7%) IPV, 5,893(5.6%) DTP-IPV-Hib vaccine and 87,054(82.7%) OPV doses were administered to children in the 2010 to 2014 birth cohorts. The proportion of children using an IPV-only schedule increased each year, consistent with the introduction of IPV that is called for by the Polio Eradication Endgame Strategic Plan 2013-2018. During this time, 4.7% children used a schedule containing both IPV and oral poliovirus vaccine (OPV). In the 2012 to 2013 birth cohorts, 14.4% children used an IPV-only schedule; 5.7% children used a sequential schedule, and 79.9% used OPV-only schedule. Use of IPV only schedules was higher among migrant children than among resident children. Among those sequential schedule using both IPV and OPV, 87.2% children used IPV for the first dose and 12.8% used OPV for the first dose. CONCLUSIONS: JNCIIMS provided a mechanism for tracking IPV and OPV vaccination patterns, and showed areas in need of improvement. Ensuring appropriately sequenced IPV and OPV supports reduction of risk of vaccine associated paralytic polio.

Immunogenicity and persistence from different 3-dose schedules of live and inactivated polio vaccines in Chinese infants.

BACKGROUND: OPV is the only poliovirus vaccine used in the China EPI system, although IPV is available in the private market. We compared immunigencity and persistence among different schedules of IPV and OPV. METHODS: 536 Chinese infants were enrolled into 4 groups receiving different schedules administered at 2, 3, and 4 months of age: IPV-OPV-OPV, IPV-IPV-OPV, IPV-IPV-IPV, and OPV-OPV-OPV. The I-I-I group received an 18-month IPV booster dose. Blood samples were collected before the first dose, after the third dose, and at 18 months for all groups, and also after the booster dose for the I-I-I group. Polio neutralizing antibody titers were assessed, and seroprotection rates were calculated after primary immunization and at 18 months of age. RESULTS: Before the first dose, GMTs of the 4 groups ranged from 2.96 to 6.89, and seroprotection rates ranged from 17.6% to 54.3%. After 3 doses, the GMT of the I-O-O and I-I-O groups ranged from 901.09 to 1,110.12, and the GMT of the I-I-I group range was 212.02 to 537.52, significantly lower than for the 2 sequential schedules (P<0.001). Seroprotection rates were 98.1% to 100%, with no significant differences among groups. At 18 months of age, the GMTs declined to a range of 527.00 to 683.44 in the I-O-O and I-I-O groups, and declined to 150.04 to 239.89 in the I-I-I group, significantly lower than for the other 3 groups (P<0.001). CONCLUSIONS: The sequential schedules achieved high GMTs and seroprotection. The IPV-only schedule achieved high seroprotection but with lower GMTs. Sequential schedules are suitable for China. With the 2 sequential schedules, GMTs remained high at 18 months of age and were not inferior to the OPV-only schedule. Thus, with a sequential schedule, the booster dose could be given at 4 years of age, the same age as the current OPV booster dose.