Xinghuo Pang

Safety and Effectiveness of a 2009 H1N1 Vaccine in Beijing

BACKGROUNDnAfter the first monovalent 2009 pandemic influenza A (H1N1) vaccine became available in September 2009, Chinese officials conducted a mass vaccination program in Beijing. We evaluated the safety and effectiveness of the vaccine.nnnMETHODSnDuring a 5-day period in September 2009, a total of 95,244 children and adults received the PANFLU.1 vaccine (Sinovac Biotech), a monovalent split-virion vaccine of 15 μg of hemagglutinin antigen without adjuvant. We assessed adverse events after immunization through an enhanced passive-surveillance system and through active surveillance, using diary cards and telephone interviews. Active surveillance for neurologic diseases was implemented in hospitals citywide. To assess vaccine effectiveness, we compared the rates of reported laboratory-confirmed cases of 2009 H1N1 virus infection in students who received the vaccine with the rates in those who did not receive the vaccine, starting 2 weeks after the mass vaccination.nnnRESULTSnAs of December 31, 2009, adverse events were reported by 193 vaccine recipients. Through hospital-based active surveillance, 362 cases of incident neurologic diseases were identified within 10 weeks after the mass vaccination, including 27 cases of the Guillain-Barré syndrome. None of the neurologic conditions occurred among vaccine recipients. From 245 schools, 25,037 students participated in the mass vaccination and 244,091 did not. During the period from October 9 through November 15, 2009, the incidence of confirmed cases of 2009 H1N1 virus infection per 100,000 students was 35.9 (9 of 25,037) among vaccinated students and 281.4 (687 of 244,091) among unvaccinated students. Thus, the estimated vaccine effectiveness was 87.3% (95% confidence interval, 75.4 to 93.4).nnnCONCLUSIONSnAmong 95,244 children and adults in Beijing, the PANFLU.1 vaccine had a safety profile similar to those of seasonal influenza vaccines and appeared to be effective against confirmed H1N1 virus infection in school-age children. (Funded by the Beijing Municipal Health Bureau.).

A varicella outbreak in a school with high one-dose vaccination coverage, Beijing, China

BACKGROUNDnVaricella vaccine is available in the private sector in China, with a single dose currently recommended for children aged ≥12 months. We investigated a varicella outbreak in a school in Beijing with high varicella vaccination coverage to describe the outbreak, examine risk factors for vaccine failure, and calculate vaccine effectiveness.nnnMETHODSnA varicella case was defined as an acute generalized maculopapular rash without other apparent cause in a student without prior varicella attending the elementary school during August 30-December 28, 2010. Varicella among vaccinated students (breakthrough varicella) was defined as varicella occurring >42 days after vaccination. Students vaccination status was verified with immunization records and clinical presentations were collected from health care practitioners.nnnRESULTSnOf the 951 students, 934 (98%) had no prior varicella history. Among these students, 916 had received 1 dose of varicella vaccine and 2 had received 2 doses (98% vaccination coverage) before the outbreak. A total of 87 cases occurred during the outbreak; most had breakthrough varicella (86/87, 99%) and mild disease (83/87, 95%). Age at vaccination (<15 months vs. ≥15 months) and time since vaccination before outbreak (<5 years vs. ≥5 years) were not associated with development of breakthrough varicella. Single-dose varicella vaccination was 89% effective in preventing any varicella and 99% in preventing moderate/severe varicella.nnnCONCLUSIONnSingle-dose varicella vaccination is highly effective in reducing varicella incidence and mitigating disease severity, but not high enough to prevent outbreak. A two-dose program might help to prevent varicella outbreaks in Beijing.

Rubella epidemic caused by genotype 1E rubella viruses in Beijing, China, in 2007–2011

BackgroundA series of different rubella vaccination strategies were implemented to control rubella and prevent congenital rubella virus infection in Beijing, China. The rubella vaccine was available in 1995 in Beijing, and was introduced into the Beijing immunization program (vaccine recipients at their own expense vaccination) in 2000, and was introduced into the National Expanded Program on Immunization (vaccine recipients free vaccination) in 2006. Rubella virological surveillance started in Beijing in 2007.ResultsThe reported rubella incidence rate has decreased dramatically due to the introduction of the vaccine in Beijing since 1995. However, rubella epidemics occurred regardless in 2001 and 2007. The incidence rate among the floating population has gradually increased since 2002, reaching 2 or more times that in the permanent resident population. The peak age of rubella cases gradually changed from <15u2009years of age to adults after 2005. Phylogenetic analysis was performed and a phylogenetic tree was constructed based on the World Health Organization standard sequence window for rubella virus isolates. All Beijing rubella virus isolates belong to genotype 1E/cluster1 and were clustered interspersed with viruses from other provinces in China. The effective number of infections indicated by a Bayesian skyline plot remained constant from 2007 to 2011.ConclusionsThe proportion of rubella cases among the floating population has increased significantly in Beijing since 2002, and the disease burden gradually shifted to the older age group (15- to 39-year olds), which has become a major group with rubella infection since 2006. Genotype 1E rubella virus continuously caused a rubella epidemic in Beijing in 2007–2011 and was the predominant virus, and all Beijing genotype 1E viruses belong to cluster 1, which is also widely circulated throughout the country.

Varicella Disease in Beijing in the Era of Voluntary Vaccination, 2007 to 2010

Background: In China, varicella vaccine has been available in the private sector to children ≥12 months of age since 1998 with a single-dose indication. In December 2006, varicella became a notifiable disease in Beijing. We used surveillance data to describe varicella vaccine uptake from 2005 to 2010 and varicella epidemiology in Beijing from 2007 to 2010. Methods: Limited sociodemographic and clinical information was available from the passive surveillance system. Varicella vaccine coverage was estimated for each year for children born between 2004 and 2008 using the number of children in the immunization registry of each birth year as the denominator without adjustment for history of varicella. Results: Vaccine coverage increased within each birth cohort between 2005 and 2010. The coverage at 2 years of age increased from 62.4% in 2005 to 74.1% in 2010 and was 80.4% in children 3–6 years of age in 2010. Between 2007 and 2010, 15,544 to 18,256 varicella cases were reported annually with stable overall incidence (range: 1.0–1.1/1000 persons), but the incidence in children 1–4 years of age decreased significantly from 6.2 per 1000 children in 2007 to 4.4 per 1000 children in 2010 (P < 0.001). Among adults (≥20 years of age), there were significant increases in the number and proportion of cases from 2557 (16.5%) in 2007 to 4277 (23.4%) in 2010 (P < 0.001). Conclusions: Moderately high 1-dose vaccine coverage in young children has been achieved with declining disease incidence, but varicella remains a common, seasonal disease in the population. Current epidemiology suggests that a government-funded varicella vaccine program that includes catch-up vaccination for older children, adolescents and adults needs consideration.

A 60-year review on the changing epidemiology of measles in capital Beijing, China, 1951-2011

BackgroundChina pledged to join the global effort to eliminate measles by 2012. To improve measles control strategy, the epidemic trend and population immunity of measles were investigated in 1951–2011 in Beijing.MethodsThe changing trend of measles since 1951 was described based on measles surveillance data from Beijing Centre of Disease Control and Prevention (CDC). The measles vaccination coverage and antibody level were assessed by routinely reported measles vaccination data and twenty-one sero-epidemiological surveys.ResultsThe incidence of measles has decreased significantly from 593.5/100,000 in 1951 (peaked at 2721.0/100,000 in 1955), to 0.5/100,000 in 2011 due to increasing vaccination coverage of 95%-99%. Incidence rebounded from 6.6/100,000 to 24.5/100,000 since 2005 and decreased after measles vaccine (MV) supplementary immunization activities (SIAs) in 2010. Measles antibody positive rate was 85%-95% in most of years since 1981. High-risk districts were spotted in Chaoyang, Fengtai and Changping districts in recent 15 years. Age-specific incidence and proportion of measles varied over time. The most affected population were younger children of 1–4 years before 1978, older children of 5–14 years in 1978–1996, infant of <1 years and adults of ≥15 years in period of aim to measles elimination.ConclusionStrategies at different stages had a prevailing effect on the epidemic dynamics of measles in recent 60 years in Beijing. It will be essential to validate reported vaccination coverage, improve vaccination coverage in adults and strengthen measles surveillance in the anticipated elimination campaign for measles.

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

BACKGROUNDnOPV 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.nnnMETHODSn536 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.nnnRESULTSnBefore 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).nnnCONCLUSIONSnThe 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.

Surface antibody and cytokine response to recombinant Chinese hamster ovary cell (CHO) hepatitis B vaccine

OBJECTIVEnTo compare the immune responses of the 10 μg and 20 μg doses of CHO hepatitis B vaccine on adults.nnnMETHODSnAdults aged 18-45 years who gave a history of never having received hepatitis B vaccine and lacked serologic evidence of infection to hepatitis B virus (HBV) infection or previous vaccination were enrolled into the study. A total of 642 eligible participants were randomized to receive 3 doses of either the 10 μg or the 20 μg formulation of CHO hepatitis B vaccine in a 0-1-6 month schedule. Each study subject had a serologic specimen collected one month following the third vaccine dose that was tested for markers of HBV infection and anti-HBs by Abbott I2000. Persons who tested negative for anti-HBs negative persons were tested for HBV DNA. Logistic regression was used to identify factors associated with antibody response. Among the participants, 153 subjects had their lymphocytes cultivated and tested for cytokine production. Enzyme-linked immunospot (ELISPOT) was used to test spot numbers of IL-4, IFN-γ which produced by lymphocyte.nnnRESULTSnThe anti-HBs seroconversion rate was 88.8% (95% CI: 85.4-92.2%) and 95.3% (95% CI: 93.0-97.6%), respectively in 10 μg and 20 μg group. Geometric mean titers (GMT) were 173.42 mIU/ml and 585.51 mIU/ml, respectively in 10 μg and 20 μg groups. Multivariate analysis demonstrated that diabetes, spouse is hepatitis B virus infector, older age and receipt of the 10 μg dose were all negatively associated with antibody response (P<.05). Cellular immunity results showed: IL-4 immunity spot numbers in 20 μg group was higher than 10 μg group. With anti-HBs increased, the IL-4 immunity spot numbers increased significantly which had significant positive correlation (Spearman coefficient=0.538, P<0.0001). IFN-γ spot numbers had no statistical significant between the two groups.nnnCONCLUSIONnThe humoral immunity and cytokines response among the group that received the 20 μg CHO hepatitis B vaccine dose was superior compared to the group that received the 10 μg dose. The 20 μg dose of CHO hepatitis B vaccine should be prioritized for adult vaccination programs in China.

An expensive adult measles outbreak and response in office buildings during the era of accelerated measles elimination, Beijing, China

BACKGROUNDnFew measles outbreaks among adults are reported in China, and outbreak response costs are seldom documented. We report an adult measles outbreak and response in 4 linked office buildings in Beijing and its associated costs.nnnMETHODnThe World Health Organization measles case definitions were used to determine suspected and confirmed measles cases. Surveillance data were used to describe the outbreak, and records and interviews of response staff were used to describe the response. Costs were determined by use of retrospective surveys of cases, review of records, and interviews of staff.nnnRESULTSnThe outbreak lasted 19days, and involved 22 cases aged 23-49years. Nineteen cases had a local household registration. All cases were employed by 8 companies in 4 linked office buildings. Among the 22 cases, 8 had temperature less than 38.5 degree, 18 had no Koplik spots and none had complications or hospitalizations. A total of 7930 contacts were identified, and of these, 6869 were employees in the office buildings. All the child contacts aged 8months-14years had been up-to-date for measles-containing vaccine (MCV); no adult could document their vaccination or measles history. Of contacts, about 96% were offered post-exposure vaccination. The total household costs were

Rapid immunization effects of a new type of 60 μg hepatitis B vaccine compared with traditional 20 μg hepatitis B vaccines in adults

13,298, or

A case control study on family history as a risk factor for herpes zoster and associated outcomes, Beijing, China

605 per case. Control costs were