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

OBJECTIVETo evaluate the immunogenicity and safety of a boost dose of inactivated polio vaccine (IPV) among children aged 18 months who had been administered with primary doses of IPV.

METHODSForm 2011 to 2012, a total of 97 children were enrolled in the present study who were vaccinated with IPV at 2, 3, 4 months of age and boosted with the same vaccine at 18 months of age. Anti-poliovirus neutralizing antibody titers in serum were measured before and after booster vaccination, geometric mean titers (GMT) and seroprotection rate were calculated. Adverse events occurring within 30 days after booster vaccination were observed, including pain, redness/swelling and induration at the injection site, fever, vomit, abnormal crying, drowsiness, loss of appetite, irritability, and all other physical discomfort and related medications were also recorded. A descriptive analysis was performed for the safety assessment.

RESULTSImmunogenicity was assessed in 84 subjects. The pre-booster seropositivity rates of neutralizing antibody against poliovirus type 1, 2, 3 before booster were all 100% (84/84) and the corresponding GMT (95% CI) was 1: 148.5 (116.49-189.29) , 1: 237.68 (178.39-316.67) and 1: 231.87 (181.27-296.58) , respectively. The seropositivity rates of neutralizing antibody against the three types of poliovirus after booster were all 100% (84/84) and the corresponding GMT (95% CI) was 1: 1612.14 (1470.57-1767.34) , 1: 1854.92 (1715.83-2005.29) and 1: 1625.50 (1452.12-1819.58) , respectively. The pre-booster titer of neutralizing antibody against poliovirus type 1, 2, 3 mainly ranged 1: 128-1: 512, which accounted for 65% (55/84) , 55% (46/84) , 74% (62/84) in each type. After the booster immunization, titers of neutralizing antibody against type 1, 2, 3 were increased as subjects with titer ≥ 1: 1024 accounted for 94% (78/84) , 95% (80/84) , 92% (77/84) , respectively.Safety was evaluated in 96 subjects, of which 16 subjects reported adverse events with the rate of 17%. The observed local events were mainly tenderness 3% (3/96) , redness/swelling and induration were not reported. The systemic adverse events included loss of appetite (8%, 8/96) , irritability (8%, 8/96) , fever (7%, 7/96) , abnormal crying (6%, 6/96) , drowsiness (6%, 6/96) and vomit (1%, 1/96) . All reported adverse events were mild or moderate. All of the local events occurred in the day of vaccination and lasted for 1-2 days, while systemic events almost developed within 2 days after vaccination and last less than 3 days.

CONCLUSIONIPV booster dose has good immunogenicity and safety profile, which provides effective protection against poliovirus.

Antibodies, Neutralizing ; blood ; Antibodies, Viral ; blood ; China ; Female ; Humans ; Immunization, Secondary ; adverse effects ; Infant ; Male ; Poliomyelitis ; prevention & control ; Poliovirus Vaccine, Inactivated ; adverse effects ; immunology ; therapeutic use

OBJECTIVETo analyze the polio immunity level of persistent population in Beijing, 2012.

METHODSA total of 1 676 subjects residing more than 6 months in Beijing were selected by stratified random cluster sampling design in 2012. Demographic characteristics, history of oral poliovirus vaccine (OPV) immunization were investigated by questionnaire. All 5 ml blood sample were collected for testing of polio neutralizing antibody using the method of microcell neutralization. The positive rate and the geometric mean titer (GMT) of polio neutralizing antibody type I, II and III were analyzed in different groups.

RESULTSThe positive rate of type I, II and III were 98.2% (1 645/1 676), 98.1% (1 644/1 676), 97.6% (1 635/1 676); The GMT were 1:130.2, 1: 113.4 and 1: 79.7. Three types of positive rates in<15 years group (99.7% (664/666), 99.8% (665/666), 99.5% (663/666)) were higher than those of ≥ 15 years group (97.1% (981/1 010), 96.9% (979/1 010), 96.2% (972/1 010)), the differences were significant (all the values of P < 0.01); The GMT in<15 years group (1:325.9, 1:250.5, 1:190.7) were higher than that of ≥ 15 years group (1: 71.1, 1: 67.2, 1: 44.8), the difference was significant (all the values of P < 0.01). The positive rate (99.0%-100%) and GMT (1: 128.8-1: 300.7) in vaccination information confirmed population were higher. The highest positive rate (all were 100%) and GMT(1: 409.7-1: 636.7) were observed in children who vaccinated three times.

CONCLUSIONThe polio antibody of healthy population was at a high level in Beijing in 2012; Especially the age groups of < 15 years which were covered by vaccines.Immunization barrier had been formed firmly to interrupt the transmission of wild poliovirus and vaccine-derived poliovirus.

Adaptive Immunity ; Adolescent ; Antibodies, Neutralizing ; Antibodies, Viral ; Child ; Humans ; Poliomyelitis ; Poliovirus ; Poliovirus Vaccine, Oral ; Vaccination ; statistics & numerical data

OBJECTIVETo evaluate the effect of outbreaks control in school settings after a 2 dose varicella vaccine immunization strategy implemented in Beijing.

METHODSEpidemiological data of varicella outbreaks in school and kindergarten settings, which were reported by all 16 districts (county) during 2007-2013 according to the technical management norms of Beijing, was collected. The first dose and second dose varicella vaccine coverage rate of eligible children after the 2 dose varicella vaccine immunization strategy implementation were estimated through BJIIMS. Based on above we analyzed the changes of outbreak quantity, case quantity and the distribution characteristics between the pre-adjustment era (2007-2011 years) and late adjustment era (2013) of the 2 dose immunization strategy.

RESULTSIn pre-adjustment era (2007-2011 years), an average of 74 (95% CI: 60-89) outbreaks was reported and 964 (95% CI: 812-1 116) cases were involved per year. In late adjustment era (2013): Outbreaks (35) declined 52.7%, involved cases (371) declined 61.5%; Outbreaks epidemic duration shortened from 22 days of pre-adjustment era to 18 days; Outbreaks involved 10-24 cases declined 64.7% (from 34 to 12); Outbreaks involved ≥ 25 cases declined 71.4% (from 7 to 2); Outbreaks of different school type as well as different regions without exception declined dramatically. Cumulative one-dose vaccine coverage in children of 2-6 yr of age was 89.6% (812 859/907 579), and cumulative second-dose vaccine coverage in children of 4-7 yr of age was 44.3% (289 764/647 732).

CONCLUSIONImplementation of a 2 dose varicella vaccine immunization strategy effectively controlled outbreaks in school and kindergarten settings.

Chickenpox ; Chickenpox Vaccine ; Child ; Child, Preschool ; Disease Outbreaks ; Epidemics ; Humans ; Schools ; Students ; Vaccination