OBJECTIVETo investigate the changes of epidemiological characteristics of measles in Beijing before and after Supplementary Immunization Campaigns (SIA) (2007-2010 vs 2011-2014) of measles-containing vaccine (MCV) among children aged between 8 months and 14 years in 2010.

METHODSDescriptive epidemiological analysis was conducted on surveillance data of measles cases (clinical cases and laboratory confirmed cases), with the occurrence during 2007-2014, and of outbreaks, with the occurrence during 2009-2014, from National Notifiable Disease Reporting System. MapInfo geographic information system (Version 8.5) was used to illustrate the distribution of measles incidence by district. Annual measles incidence was classified into 5 groups at the same intervals between the upper and lower limits to analyze the morbidity of the different areas.

RESULTSIn total, 7 722 and 3 132 measles cases were reported during 2007-2010 and 2011-2014, with the annual incidence of 11.59 and 3.84 cases per 100 000 population, respectively. Comparing with the results during 2007-2010, total number of measles cases and average annual incidence during 2011-2014 were decreased by 59.4%, and 66.9%, respectively. Among measles cases during 2011-2014, percentage of cases aged 15 years or above were 57.7%(56/97), 62.0%(49/79), 65.5%(370/565), and 71.4% (1 707/2 391), respectively, which increased by years. During 2007-2010, the highest risk age for adults was 20-34, while 2011-2014, 5 years older: 25-39. During 2009-2010, 2011-2012, and 2013-2014, 50.3% (447/889), 30.3% (10/33), and 57.8% (201/348), respectively, of measles cases aged 8-17 months were unvaccinated by MCV. Percentages of measles cases aged 0-7 months, 8 months-14 years, 15-39 years and 40 years or above during 2013-2014, who visited hospitals 7-21 days before disease onset, were 59.8% (238/398), 49.3% (237/481), 32.2% (529/1641), and 37.6% (164/436), respectively. A total of 11 nosocomial measles outbreaks occurred during 2013-2014, which was much higher than that during 2009-2010 (2 nosocomial outbreaks). And universities accounted for the majority of outbreak settings of schools (3/4). All 11 outbreaks among grouped employees during 2009-2012 occurred in factories, restaurants, or large shopping centers, while the largest proportion (6/16) of that kind of outbreaks during 2013-2014 occurred in office buildings.

CONCLUSIONSSIA of MCV in 2010 effectively decreased measles transmission in Beijing. But routine immunization of MCV still needed to be improved. The issue of adult measles has been a prominent problem. Hospitals, office buildings and universities were the focus of prevention of measles transmission.

Adolescent ; Adult ; Beijing ; epidemiology ; Child ; Child, Preschool ; Cross Infection ; Disease Outbreaks ; Geographic Information Systems ; Humans ; Immunization Programs ; statistics & numerical data ; Incidence ; Infant ; Measles ; epidemiology ; Measles Vaccine ; administration & dosage ; Restaurants ; Schools ; Vaccination ; statistics & numerical data ; Young Adult

Objective:To assess the effectiveness of 1 dose varicella attenuated live vaccine (VarV) for healthy children aged 1-12 years in China and explore the application of the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) framework in observational studies of vaccine effectiveness (VE).Methods:We searched studies about the VE of 1-dose VarV for children aged 1-12 years in China which published before 2019 and evaluated the quality of the studies by the Newcastle Ottawa Scale (NOS) table. We used Meta-analysis models to obtain the pooled 1-dose VE and that in subgroups by study design, outbreak or not, study quality and age of subjects. The evidences of VEs were rated by means of the GRADE system.Results:Thirty-two studies were included and the pooled 1-dose VE was 75% [95% confidence interval ( CI): 68%-80%]. The VE of outbreak studies [VE=66% (95 %CI: 57%-73%)] was lower than non-outbreak studies [VE=85% (95 %CI: 78%-89%)], and the VE in <6 years old children [VE=84% (95 %CI:77%-89%)] was higher than that in ≥6 years old children [VE=60% (95 %CI: 51%-68%)]. There was no significant difference in VE among studies with different design and quality. The quality of the evidences of pooled 1-dose VE was"very low", which was downgraded in bias risk and inconsistency and not downgraded in indirectness, imprecision and publication bias. Conclusions:The 1-dose VarV can provide medium level protection for 1-12 years old children in China, but it will decrease significantly for ≥6 years old children, so it is suggested to implement the strategies of two-dose vaccination of VarV in children <6 years old. The GRADE framework can be used in the observational studies of VE and it is suggested that the technical guidelines of observational study should be worked out to improve the overall quality of evidence.

Objective:To analyze the changing trend of polio vaccine immunization effectiveness and vaccine titer in Beijing in 2012, 2014, 2016 and 2018 before and after the adjustment of polio vaccine immunization program strategy.Methods:According to the convenient sampling method,the vaccination clinics of Chaoyang and Yanqing Districts in 2012, Fengtai and Daxing Districts in 2014, Tongzhou and Pinggu Districts in 2016, Dongcheng and Shunyi Districts in 2018 were selected as monitoring points. A total of 292 children were selected 4-8 weeks after the completion of 3 doses polio vaccine basic immunization which were 3 doses of trivalent oral poliovirus vaccine（tOPV）schedule before the strategy adjustment in 2012-2014 and 1 dose of inactivated poliovirus vaccine (IPV) following 2 doses of bivalent oral poliovirus vaccine (bOPV) sequential schedule after the adjustment in 2016-2018. About 1.0 ml blood samples were collected to detect type Ⅰ and Ⅲ neutralizing poliovirus antibody. A total of 9 oral poliovirus vaccines (8 vaccines in 2012) were selected from different sources of vaccine storage every year to test the vaccine titer using random number method .Results:The [ M（ P25， P75）] age of 292 children was 5 (5, 6) months, and the ratio of male to female was 1.04 (149/143). In 2012, 2014, 2016 and 2018, 66,72,68 and 86 children were investigated respectively. After basic immunization, antibody positive rates for type Ⅰ and Ⅲ poliovirus were 100%, except 98.61% (71) for type Ⅰ poliovirus in 2014. The neutralizing antibody titer of type Ⅰ and Ⅲ poliovirus was higher in 2016 and 2018 than that in 2012 and 2014 ( P<0.001). The average titer of tOPV were (6.05±0.15) and (6.16±0.12) lgCCID 50 per dose in 2012 and 2014. The average titer of bOPV were (6.88±0.21) and (6.26±0.14) lgCCID 50 per 100 μl in 2016 and 2018 ( P<0.001). Conclusion:Before and after the adjustment of polio vaccine immunization strategy in Beijing, the basic immunization success rate of the IPV-bOPV sequential immunization schedule was good as well as full tOPV schedule. The level of polio antibody produced by the IPV-bOPV sequential immunization schedule was higher. After adjustment, bOPV titer in 2016 was significantly higher than those before adjustment, while bOPV titer decreased significantly in 2018.

Objective:To analyze the changing trend of polio vaccine immunization effectiveness and vaccine titer in Beijing in 2012, 2014, 2016 and 2018 before and after the adjustment of polio vaccine immunization program strategy.Methods:According to the convenient sampling method,the vaccination clinics of Chaoyang and Yanqing Districts in 2012, Fengtai and Daxing Districts in 2014, Tongzhou and Pinggu Districts in 2016, Dongcheng and Shunyi Districts in 2018 were selected as monitoring points. A total of 292 children were selected 4-8 weeks after the completion of 3 doses polio vaccine basic immunization which were 3 doses of trivalent oral poliovirus vaccine（tOPV）schedule before the strategy adjustment in 2012-2014 and 1 dose of inactivated poliovirus vaccine (IPV) following 2 doses of bivalent oral poliovirus vaccine (bOPV) sequential schedule after the adjustment in 2016-2018. About 1.0 ml blood samples were collected to detect type Ⅰ and Ⅲ neutralizing poliovirus antibody. A total of 9 oral poliovirus vaccines (8 vaccines in 2012) were selected from different sources of vaccine storage every year to test the vaccine titer using random number method .Results:The [ M（ P25， P75）] age of 292 children was 5 (5, 6) months, and the ratio of male to female was 1.04 (149/143). In 2012, 2014, 2016 and 2018, 66,72,68 and 86 children were investigated respectively. After basic immunization, antibody positive rates for type Ⅰ and Ⅲ poliovirus were 100%, except 98.61% (71) for type Ⅰ poliovirus in 2014. The neutralizing antibody titer of type Ⅰ and Ⅲ poliovirus was higher in 2016 and 2018 than that in 2012 and 2014 ( P<0.001). The average titer of tOPV were (6.05±0.15) and (6.16±0.12) lgCCID 50 per dose in 2012 and 2014. The average titer of bOPV were (6.88±0.21) and (6.26±0.14) lgCCID 50 per 100 μl in 2016 and 2018 ( P<0.001). Conclusion:Before and after the adjustment of polio vaccine immunization strategy in Beijing, the basic immunization success rate of the IPV-bOPV sequential immunization schedule was good as well as full tOPV schedule. The level of polio antibody produced by the IPV-bOPV sequential immunization schedule was higher. After adjustment, bOPV titer in 2016 was significantly higher than those before adjustment, while bOPV titer decreased significantly in 2018.