Chuanxi Fu

Antibodies against H5 and H9 avian influenza among poultry workers in China.

The authors assessed the risk of avian influenza virus infection among humans by conducting a serologic surveillance study in Guangzhou. The findings highlight the potential risk of H9 avian influenza virus to public health.

Effectiveness of the Lanzhou lamb rotavirus vaccine against gastroenteritis among children.

The Lanzhou lamb rotavirus (LLR) vaccine has been in use in China since 2000. This study evaluated this vaccines effectiveness using a case-control design in Guangzhou. In the study area, there were 3130 laboratory-confirmed rotavirus gastroenteritis cases in children between 2 and 35 months old from 2009 to 2011. A total of 3607 controls were also enrolled in this study. Of the subjects, 970 (14.4%) had received 1 dose of the LLR vaccine. Because of the low vaccination rate, we only obtained an effectiveness of 44.3% (95% CI, 28.4-56.7%) for children 9-11 months old, 52.8% (40.8-62.3%) for children 12-17 months old, and 51.8% (11.6-73.8%) for children 18-35 months old for one dose. This post-marketing study found that one dose of the LLR vaccine confers partial protection when given to children between 9 and 35 months old. Therefore, earlier immunization and the administration of the full immunization regimen should be encouraged.

The Effectiveness of Varicella Vaccine in China

Background: The attenuated live varicella vaccine had been shown to be effective in preventing varicella and reducing the disease burden in the United States. However, little work has been done on investigating vaccine effectiveness in China where 3 varicella vaccines are available. Although the vaccines contain the same strain of virus, the vaccines licensed in China were from manufacturers different from the one licensed in the United States. We conducted a matched case–control study to assess the effectiveness of the 3 varicella vaccines in use in China. Methods: In 2005, we enrolled 1000 cases from Guangzhou, China and 1000 controls matched by age and place of residence. The cases were children clinically diagnosed with acute onset of a diffuse maculopapulovesicular rash without other apparent cause. We interviewed the legal guardians of the participants for demographic information and disease history after obtaining informed consent. We collected information on vaccination status from electronic vaccination records. Results: The 3 varicella vaccines in China (Varilrix from GlaxoSmithKline, Changchun and Shanghai from Changchun and Shanghai Institutes of Biologic Products, respectively) had similar effectiveness: Varilrix 86.4% (95% confidence interval [CI]: 72.6, 93.2), Changchun 79.5% (95% CI: 58.1, 90.0), and Shanghai 92.6% (95% CI: 68.9, 98.2). Vaccine effectiveness was higher during the first year after vaccination than during the subsequent 5 years, but the differences did not reach statistical significance. Conclusions: The varicella vaccines in China are highly effective in preventing clinical varicella. Further studies on laboratory-confirmed cases are needed to verify the change of vaccine-induced immunity over time.

Emergence of dengue virus 4 genotype II in Guangzhou, China, 2010: Survey and molecular epidemiology of one community outbreak

BackgroundThe re-emergence of dengue virus 4 (DENV-4) has become a public health concern in South America, Southeast Asia and South Asia. However, it has not been known to have caused a local outbreak in China for the past 20 years. The purpose of this study was to elucidate the epidemiology of one local community outbreak caused by DENV-4 in Guangzhou city, China, in 2010; and to determine the molecular characteristics of the genotype II virus involved.Case presentationsDuring September and October of 2010, one imported case, a Guangzhou resident who travelled back from Thailand, resulted in 18 secondary autochthonous cases in Guangzhou City, with an incidence rate of 5.53 per 10,000 residents. In indigenous cases, 14 serum samples tested positive for IgM against DENV and 7 for IgG from a total of 15 submitted serum samples, accompanied by 5 DENV-4 isolates. With identical envelope gene nucleotide sequences, the two isolates (D10168-GZ from the imported index case and Guangzhou 10660 from the first isolate in the autochthonous cases) were grouped into DENV-4 genotype II after comparison to 32 previous DENV-4 isolates from GenBank that originated from different areas.ConclusionsBased on epidemiological and phylogenetic analyses, the outbreak, which was absent for 20 years after the DENV-4 genotype I outbreak in 1990, was confirmed as DENV-4 genotype II and initially traced to the imported index case, a Guangzhou resident who travelled back from Thailand.

The immunogenicity and safety of vaccination with purified Vero cell rabies vaccine (PVRV) in China under a 2-1-1 regimen.

Background. In China, rabies vaccine is only permitted to use under the Essen 5-dose regimen for the rabies post-exposure prophylaxis (PEP). However, Purified chick embryo cell vaccine made in India (Rabipur) has been approved in use under 2-1-1 immune program in 2010. Our objective is to confirm the immunogenicity and safety of PVRV manufactured in China (SPEEDA) under 2-1-1 program, compared with Rabipur and with the Essen 5-dose regimen. Methods. A total of 112 subjects were divided into three groups: 50 subjects in test group A, 32 subjects in control group B and 30 subjects in control group C. “Zagreb” 2-1-1 program was chosen for group A and B using SPEEDA and Rabipur, “Essen” 5-dose regimen was adopted for group C using SPEEDA, thus to observe the general and local reactions within 72h post vaccination. Serum samples were also collected at D0, D7, D14 and D45 to determine the rabies serum neutralizing antibody by rapid fluorescent focus inhibition test (RFFIT). Results. All groups showed similar immunogenicity. The neutralizing antibody titers at D14 and D45 of all subjects showed more than 0.5IU/ml. No moderate and severe adverse effects were observed, though mild adverse reactions may occur. Conclusions. PVRV (SPEEDA), under 2-1-1 regimen, is equally safe and immunogenic as the PCECV (Rabipur) for post-exposure prophylaxis vaccination.

Low measles seropositivity rate among children and young adults: A sero-epidemiological study in southern China in 2008

To obtain sero-epidemiological profile and develop optimal strategies to promote measles elimination, we conducted a measles seroprevalence study using stratified sampling method in Guangzhou, southern China in 2008. 4036 samples were analyzed by the enzyme-linked immunosorbent assay method and the overall sero-positive rate of measles antibody was 70.6% (95% CI 69.2-72.0%). Positive seroprevalences differed among age groups (P=0.000) and a W-curve distribution was observed. The 15-29 years group had the low positive rate of 58.8% (95% CI 54.9-62.7%). Catch-up vaccination campaigns should be promoted among susceptible population of ≤ 29 year olds including women of childbearing age.

Technical guidelines for the application of seasonal influenza vaccine in China (2014–2015)

Influenza, caused by the influenza virus, is a respiratory infectious disease that can severely affect human health. Influenza viruses undergo frequent antigenic changes, thus could spread quickly. Influenza causes seasonal epidemics and outbreaks in public gatherings such as schools, kindergartens, and nursing homes. Certain populations are at risk for severe illness from influenza, including pregnant women, young children, the elderly, and people in any ages with certain chronic diseases.

Matched case-control study of effectiveness of live, attenuated S79 mumps virus vaccine against clinical mumps.

ABSTRACT Mumps virus infection is a potentially serious viral infection of childhood and early adulthood. In China, live, attenuated S79 mumps virus vaccine has been licensed for pediatric use since 1990. There has been no assessment of its efficacy. Thus, the objective of this study was to determine the effectiveness of live, attenuated S79 mumps virus vaccine against clinical mumps. Cases were selected from the China Information System for Disease Control and Prevention during September 2004 to March 2005. Each case was matched to a control by gender, age, and area of residency. In all, 469 cases and 469 controls were enrolled in the study. Vaccination information was obtained from the Childrens EPI Administrative Computerized System. Vaccine effectiveness (VE) was calculated for one or two doses of S79 vaccine, with 95% confidence intervals (CI). VE of mumps virus vaccine for one dose versus none was protection of 86.0% (95% CI, 77.2% to 91.5%) of recipients, and VE was much higher in the first 4 years than in the 5 to 12 years after vaccination. The S79 vaccine can effectively prevent clinical mumps, and a second dose of mumps virus vaccine is necessary for the protection of children in China.

Seasonal Influenza Vaccine Effectiveness among Children Aged 6 to 59 Months in Southern China

In China the protective effect of seasonal influenza vaccine has only been assessed in controlled clinical trials and proven to be highly effective. However, the post-licensure effectiveness of influenza vaccine has not been examined. In our study all influenza cases from the 19 surveillance sites in Guangzhou were laboratory confirmed during 2009 and 2010. Controls were randomly selected from children aged 6 to 59 months in the Childrens Expanded Programmed Immunization Administrative Computerized System. 2529 cases and 4539 controls were finally enrolled. After adjusting for gender, age and area of residence, the vaccine effectiveness of full vaccination was 51.79% and 57.78% in the 2009 and 2010 influenza season, respectively. Partial vaccination provided 39.38% and 35.98% protection to children aged 24 to 59 months in 2009 and 2010, respectively, and no protective effect was observed among younger children. Full vaccination is highly protective and partial vaccination is protective for older children. Influenza vaccination in general should be encouraged, and full vaccination should be particularly encouraged because its protective effect is much stronger than that of partial vaccination.

Concurrent and cross-season protection of inactivated influenza vaccine against A(H1N1)pdm09 illness among young children: 2012-2013 case-control evaluation of influenza vaccine effectiveness.

In 2012-2013, we examined 1729 laboratory-confirmed A(H1N1)pdm09 influenza cases matched 1:1 with healthy controls and estimated influenza vaccine effectiveness (VE) for trivalent inactivated influenza vaccine (IIV3) to be 67% (95% confidence interval=58-74%) for ages 8 months to 6 years old. Among children aged 8-35 months old, VE for fully vaccinated children (73%, 60-81%) was significantly higher than VE for partially vaccinated children (55%, 33-70%). Significant cross-season protection from prior IIV3 was noted, including VE of 31% (8-48%) from IIV3 received in 2010-2011 against influenza illness in 2012--2013 without subsequent boosting doses.