ABSTRACT
Objective: To understand the incidence of delayed vaccination with the national immunization program vaccines among children aged 0-6 years in Xuhui District, Shanghai, and to evaluate the safety of delayed vaccination. Methods: A stratified random sampling was used to obtain six vaccination clinics in Xuhui District, Shanghai. The vaccination records of children 0-6 years from these six vaccination clinics were collected from the Shanghai Immunization Program Information Management System. Adverse events following immunization (AEFI) data were collected from the China Information System for Disease Control and Prevention. Descriptive epidemiology was used to analyze the data. Children were divided into the timely vaccination group and delayed vaccination group according whether they were delayed in vaccination (received one month or more after the recommended age among children aged ≤1 year; received three months or more after the recommended age among children aged >1 year). The safety of four vaccination methods-individual vaccination, simultaneous vaccination, routine vaccination and combined vaccination-were further compared. Differences between groups were compared using chi-square test. Results: From 2019 to 2021, six vaccination clinics in Xuhui District administered 124 031 doses of the national immunization program vaccines among children aged 0-6 years, and delayed vaccinations accounted for 25.99% (32 234/124 031) of these doses. In 2020, the delayed vaccination rate during the first-level COVID-19 public health emergency response period in Shanghai was significantly higher than that in the same period in 2019 (34.70% vs. 24.19%, χ2=136.23, P<0.05). The delayed vaccination rate during the COVID-19 vaccination campaign in 2021 was significantly higher than that in the same period in 2019 (25.27% vs. 22.55%, χ2=82.80, P<0.05). From 2019 to 2021, a total of 475 cases of AEFI were reported in six vaccination clinics, with a reported incidence of 382.97 per 100 000 doses, including 421 cases of common adverse reaction (88.63%, 339.43 per 100 000 doses), 51 cases of rare adverse reaction (10.74%, 41.12 per 100 000 doses) and 3 cases of coincidences (0.63%, 2.42 per 100 000 doses). The reported incidence of AEFI among delayed vaccinations was significantly lower than that among timely vaccinations (291.62 per 100 000 doses vs. 415.05 per 100 000 doses). The incidence of AEFI for the four delayed vaccination methods (individual vaccination, simultaneous vaccination, routine vaccination and combined vaccination) was lower than that for timely vaccination. There were significant differences between the groups except for the routine vaccination group (χ2=9.82, P<0.05; χ2=5.46, P<0.05; χ2=2.97, P>0.05; χ2=11.89, P<0.05). Conclusions: In Xuhui District of Shanghai, 25.99% of doses of the national immunization program vaccines administered to children 0-6 years were delayed. Delayed vaccination does not increase the risk of AEFI compared with timely vaccination.
ABSTRACT
Objective:This study aimed to investigate the time duration of norovirus shedding among day-care children and students during norovirus outbreaks， as well as influencing factors affecting the viral shedding. Methods:Suspected cases of norovirus infection and their close contacts were collected from child care and school settings during norovirus outbreaks in Xuhui District， Shanghai， from 2017 through 2019. Specimens were detected using real-time RT-PCR to determine whether children had been infected with norovirus. Subsequently， further specimens were collected every 3-7 days from infected children until specimens tested negative for norovirus. Results:A total of 76 outbreaks were reported involving 1 014 suspected cases. In the 421 suspected cases， 311 confirmed cases were diagnosed after examination. Furthermore， a total of 58 confirmed cases participated in this study with informed consent， with a participation rate of 18.65%. The average time duration of norovirus shedding was （16.24±13.80） days， in which 79.31% had viral shedding more than 7 days， 37.93% more than 14 days and 17.24% more than 21 days. A Cox proportional-hazards model showed that children with more severe symptoms （HR=2.06，P=0.040）， day-care children （HR=4.13，P=0.012）， and confirmed cases in 2019 （HR=0.11，P<0.001） had longer duration of viral shedding. Conclusion:Children may remain shedding norovirus after their recovery and back to class. Improvement in sanitation for these recovered children in child care and schools is especially necessary， which may avert secondary transmission.
ABSTRACT
Objective ] To analyze the occurrence of adverse events following immunization (AEFI)of Bacille Calmette-Guerin vaccine(BCG)among neonates in IPMCH, and to evaluate the safety of BCG. [Methods] Data on BCG AEFI in 2010-2013 were collected through national AEFI information system.The descriptive methodology was used in this study . [ Results] During 2010 -2013, the coverage rate of the BCG vaccine among neonates in IPMCH was 95 .19%.And 21 BCG AEFI cases vaccinated were reported, with a reporting rate of 430.86 per 1 million doses, most of which were BCG lymphadenitis(20 cases with the incidence of 410.34 per 1 million doses). [Conclusion] The coverage rate of the BCG vaccination among neonates in IPMCH remained at high level .BCG vaccine proved safe . Most of rare vaccine reactions were BCG lymphadenitis , and the reporting rate of BCG lymphadenitis were lower than expected .