Lei Cao

Safety of Influenza A (H1N1) Vaccine in Postmarketing Surveillance in China

BACKGROUNDnOn September 21, 2009, China began administering vaccines, obtained from 10 different manufacturers, against 2009 pandemic influenza A (H1N1) virus infection in priority populations. We aimed to assess the safety of this vaccination program.nnnMETHODSnWe designed a plan for passive surveillance for adverse events after immunization with the influenza A (H1N1) vaccine. Physicians or vaccination providers were required to report the numbers of vaccinees and all adverse events to their local Center for Disease Control and Prevention (CDC), which then reported the data to the Chinese CDC through the online National Immunization Information Systems National Adverse Event Following Immunization Surveillance System. Data were collected through March 21, 2010, and were verified and analyzed by the Chinese CDC.nnnRESULTSnA total of 89.6 million doses of vaccine were administered from September 21, 2009, through March 21, 2010, and 8067 vaccinees reported having an adverse event, for a rate of 90.0 per 1 million doses. The age-specific rates of adverse events ranged from 31.4 per 1 million doses among persons 60 years of age or older to 130.6 per 1 million doses among persons 9 years of age or younger, and the manufacturer-specific rates ranged from 4.6 to 185.4 per 1 million doses. A total of 6552 of the 8067 adverse events (81.2%; rate, 73.1 per 1 million doses) were verified as vaccine reactions; 1083 of the 8067 (13.4%; rate, 12.1 per 1 million doses) were rare and more serious (vs. common, minor events), most of which (1050) were allergic reactions. Eleven cases of the Guillain-Barré syndrome were reported, for a rate of 0.1 per 1 million doses, which is lower than the background rate in China.nnnCONCLUSIONSnNo pattern of adverse events that would be of concern was observed after the administration of influenza A (H1N1) vaccine, nor was there evidence of an increased risk of the Guillain-Barré syndrome.

Progress Toward Measles Elimination in the People's Republic of China, 2000–2009

In 2006, China set a goal of measles elimination by 2012. To describe progress toward this goal, we reviewed relevant policies and strategies and analyzed national data for 2000-2009. In response to implementation of these strategies, including increased routine measles vaccination coverage and province-specific supplementary immunization activities (SIAs), reported measles incidence decreased to a historically low level of 39.5 cases per million in 2009. A synchronized nationwide SIA was scheduled in 2010 to further decrease susceptibility to measles. However, reaching and maintaining measles elimination will require strong political commitment and efforts for strengthening surveillance, increasing 2-dose vaccine coverage to >95%, stricter enforcement of the requirement to check immunization status at school entry, and careful attention to measles susceptibility in those aged ≥15 years.

Human Infection with West Nile Virus, Xinjiang, China, 2011

To the Editor: West Nile virus (WNV) is a mosquito-borne flavivirus in the Japanese encephalitis serocomplex of the family Flaviviridae (1). It has been reported in Africa, Asia, Europe, Australia, and North America, and is recognized as the most globally widespread mosquito-borne flavivirus (2). Isolation of WNV has previously been attempted in China, Japan and South Korea; however, no virus has been isolated (3–5). We report isolation of WNVs from mosquitoes in Xinjiang Uyghur Autonomous Region in western China. We also provide evidence of WNV human infections confirmed by IgM ELISA and seroconversion by 90% plaque reduction neutralization tests of paired serum samples obtained from persons with febrile illness and viral encephalitis in 2011.

Enhanced surveillance of acute flaccid paralysis following importation of wild poliovirus in Xinjiang Uygur Autonomous Region, China

BackgroundAfter being polio free for more than 10 years, an outbreak occurred in China in 2011 in Xinjiang Uygur Autonomous Region (Xinjiang) following the importation of wild poliovirus (WPV) originating from neighboring Pakistan.MethodsTo strengthen acute flaccid paralysis (AFP) surveillance in Xinjiang, “zero case daily reporting” and retrospective searching of AFP cases were initiated after the confirmation of the WPV outbreak. To pinpoint all the polio cases in time, AFP surveillance system was expanded to include persons of all ages in the entire population in Xinjiang.ResultsTotally, 578 AFP cases were reported in 2011 in Xinjiang, including 21 WPV cases, 23 clinical compatible polio cases and 534 non-polio AFP cases. Of the 44 polio cases, 27 (61.4%) cases were reported among adults aged 15–53 years. Strengthening AFP surveillance resulted in an increase in the number of non-polio AFP cases in 2011 (148 children < 15 years) compared with 76 cases < 15 years in 2010. The AFP surveillance system in Xinjiang was sensitive enough to detect polio cases, with the AFP incidence of 3.28/100,000 among children < 15 years of age.ConclusionsIncorporating adult cases into the AFP surveillance system is of potential value to understand the overall characteristics of the epidemic and to guide emergency responses, especially in countries facing WPV outbreak following long-term polio free status. The AFP surveillance system in Xinjiang was satisfactory despite limitations in biological sample collection.

Identification of a Newly Isolated Getah Virus in the China-Laos Border, China

In this study, we isolated a virus strain (YN12031) from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic effect (CPE) 32 h post-infection. The virus particles were spherical, 70 nm in diameter, and enveloped; they also featured surface fibers. Molecular genetic analysis revealed that YN12031 was closely related to alpha viruses such as Chikungunya virus and Sindbis virus, and located in the same clade as MM2021, the prototype of Getahvirus (GETV) isolated in Malaysia in 1955. Phylogenetic analysis of the E2 and capsid genes further revealed that YN12031 was located in the same clade as the Russian isolate LEIV/16275/Mag. Analysis of the homology of nucleotides and amino acids in the coding area and E2 gene demonstrated that the YN12031 isolated from the China-Laos border (tropical region) was related closest to the LEIV/16275/Mag isolate obtained in Russia (North frigid zone area) among other isolates studied. These results suggest that GETV can adapt to different geographical environments to propagate and evolve. Thus, strengthening the detection and monitoring of GETV and its related diseases is very crucial.

Effect of aluminum hydroxide adjuvant on the immunogenicity of the 2009 pandemic influenza A/H1N1 vaccine: multi-level modeling of data with repeated measures.

OBJECTIVEnTo evaluate the effect of the aluminum hydroxide (Al-OH) adjuvant on the 2009 pandemic influenza A/H1N1 (pH1N1) vaccine.nnnMETHODSnIn a multicenter, double-blind, randomized, placebo-controlled trial, participants received two doses of split-virion formulation containing 15 μg hemagglutinin antigen, with or without aluminum hydroxide (Al-OH). We classified the participants into six age categories (>61 years, 41-60 years, 19-40 years, 13-18 years, 8-12 years, and 3-7 years) and obtained four blood samples from each participant on days 0, 21, 35, and 42 following the first dose of immunization. We assessed vaccine immunogenicity by measuring the geometric mean titer (GMT) of hemagglutination inhibiting antibody. We used a two-level model to evaluate the fixed effect of aluminum Al-OH and other factors, accounting for repeated measures.nnnRESULTSnThe predictions of repeated measurement on GMTs of formulations with or without Al-OH, were 80.35 and 112.72, respectively. Al-OH significantly reduced immunogenicity after controlling for time post immunization, age-group and gender.nnnCONCLUSIONnThe Al-OH adjuvant does not increase but actually reduces the immunogenicity of the split-virion pH1N1 vaccine.

Detection of West Nile Virus Infection in Viral Encephalitis Cases, China

This study detected West Nile virus (WNV) infection in serum samples of patients clinically diagnosed with viral encephalitis in the Japanese encephalitis virus (JEV) endemic area (seven provinces) and JEV nonendemic area (Xinjiang province) in China from 2011 to 2012. In JEV endemic areas, there were 22 positive cases of WNV immunoglobulin M (IgM) antibody in serum specimens of 65 JEV patients (JEV IgM antibody positive) in the acute phase, whereas WNV IgM antibodies were not detected in serum specimens of 63 non-JEV patients (JEV IgM antibody negative). However, the titer of JEV-neutralizing antibody was four times higher than that of WNV-neutralizing antibody in WNV-IgM-positive serum specimens. Detection was also conducted in serum specimens collected from 12 patients clinically diagnosed as viral encephalitis in Xinjiang; five serum specimens were WNV IgM antibody positive, and there were fourfold differences in WNV-neutralizing antibody titers between convalescent and acute serum. Meanwhile JEV-neutralizing antibody titer was negative or significantly lower than that of WNV-neutralizing antibody in the same specimens. WNV IgM antibodies positive were detected in acute serum specimens of patients clinically diagnosed with JEV infection in JEV-endemic areas, but no WNV neutralization antibodies were detected fourfold greater than that of the corresponding JEV antibodies. Clinical cases of WNV infection were detected in patients clinically diagnosed with viral encephalitis in Xinjiang.

Routine immunization services costs and financing in China, 2015

OBJECTIVEnTo estimate the costs of routine immunization (RI) services in China in 2015, to provide objective data relevant to investment in the Expanded Program on Immunization, and to contribute to global data on costing and financing of RI.nnnMETHODSnThe study was conducted between January and March 2016. We selected 276 villages, 138 townships, 46 counties, and 40 prefectures from 15 provinces as investigation sites at random, stratified by eastern, middle, and western regions. Direct cost items included vaccines, personnel, cold chain, surveillance, communication, training, and supervision at the national, provincial, prefecture, county, township, and village levels. We obtained financial data from governmental and external sources. Indirect costs of RI included parents transportation costs and productivity lost due to taking their children for vaccination.nnnRESULTSnTotal direct costs were

Evaluation of a school entry immunization record check strategy in 4 counties of Ningxia and Hubei provinces, China

92.42 for each child fully immunized (

Evaluation of the impact of Shandong illegal vaccine sales incident on immunizations in China

4.20/dose), which equates to