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1.  Varicella vaccine uptake in Shandong province, China 
Human Vaccines & Immunotherapeutics  2012;8(9):1213-1217.
Varicella vaccine has been licensed in China for decade to be used as single dose in children aged ≥ 12 mo of age in private sector. Little data were available on varicella uptake to date in China yet. A cross-sectional study was conducted in Shandong Province in May 2011 to examine varicella vaccination coverage among children aged 16–40 mo and examine factors associated with varicella vaccine uptake. The overall coverage among children eligible for varicella vaccine was 62% (range 16.7–94.7% by county), much lower than the coverage of the eight vaccines included in the national immunization program (all above 97%). Though proximity to immunization services (< 5 km) was linked with higher vaccine uptake (62.6 vs. 37.4%, p = 0.02), county-level economic development (77.8, 61.0 and 47.1% for developed, sub-developed and developing regions, respectively, p < 0.001) played an even more important role in varicella vaccination. Moreover, there was little variation in coverage of vaccines included in the national immunization program along with county-level economic development. Even though varicella vaccine uptake is relatively high for use on a private basis, the vaccination coverage is not high enough to prevent epidemiology shift to adolescents and adults who are more prone to develop severe outcomes to varicella. Further enhancement on varicella vaccination coverage is necessary and inclusion to national immunization program seems to be a promising option for achieving and maintaining high coverage.
PMCID: PMC3579900  PMID: 22894966
varicella; chickenpox; vaccine; uptake; coverage
2.  Rubella Epidemics and Genotypic Distribution of the Rubella Virus in Shandong Province, China, in 1999–2010 
PLoS ONE  2012;7(7):e42013.
The rubella vaccine was introduced into the immunization program in 1995 in the Shandong province, China. A series of different rubella vaccination strategies were implemented at different stages of measles control in Shandong province.
Methodology/Principal Findings
The average reported incidence rate of rubella cases remained at a low level in Shandong province after 1999. However, rubella epidemics occurred repeatedly in 2001/2002, 2006, and 2008/2009. The age of the onset of rubella cases gradually increased during 1999–2010, which showed that most cases were found among the 10 years old in 1999 and among the 17 years old in 2010. Phylogenetic analysis was performed and a phylogenetic tree was constructed based on the World Health Organization standard sequence window for rubella virus isolates. All rubella viruses isolated in Shandong province were divided into 4 genotypes: 1E, 1F, 2A, and 2B. Genotype 1E viruses accounted for the majority (79%) of all these viruses. The similarity of nucleotide and amino acid sequences among genotype 1E viruses was 98.2–100% and 99.1–100%, respectively. All Shandong genotype 1E strains, differed from international genotype 1E strains, belonged to cluster 1 and interdigitated with the viruses from other provinces in mainland China. The effective number of infections indicated by a Bayesian skyline plot remained constant from 2001 to 2009.
The gradual shift of disease burden to an older age group occurred after a rubella-containing vaccine was introduced into the childhood immunization schedule in 1995 in Shandong province. Four genotypes, including 1E, 1F, 2A, and 2B, were found in Shandong province during 2000–2009. Genotype 1E, rather than genotype 1F, became the predominant genotype circulating in Shandong province from 2001. All Shandong genotype 1E viruses belong to the genotype 1E/cluster 1; they have constantly circulated, and co-evolved and co-circulated, with those from other provinces.
PMCID: PMC3404038  PMID: 22911874
3.  Single Endemic Genotype of Measles Virus Continuously Circulating in China for at Least 16 Years 
PLoS ONE  2012;7(4):e34401.
The incidence of measles in China from 1991 to 2008 was reviewed, and the nucleotide sequences from 1507 measles viruses (MeV) isolated during 1993 to 2008 were phylogenetically analyzed. The results showed that measles epidemics peaked approximately every 3 to 5 years with the range of measles cases detected between 56,850 and 140,048 per year. The Chinese MeV strains represented three genotypes; 1501 H1, 1 H2 and 5 A. Genotype H1 was the predominant genotype throughout China continuously circulating for at least 16 years. Genotype H1 sequences could be divided into two distinct clusters, H1a and H1b. A 4.2% average nucleotide divergence was found between the H1a and H1b clusters, and the nucleotide sequence and predicted amino acid homologies of H1a viruses were 92.3%–100% and 84.7%–100%, H1b were 97.1%–100% and 95.3%–100%, respectively. Viruses from both clusters were distributed throughout China with no apparent geographic restriction and multiple co-circulating lineages were present in many provinces. Cluster H1a and H1b viruses were co-circulating during 1993 to 2005, while no H1b viruses were detected after 2005 and the transmission of that cluster has presumably been interrupted. Analysis of the nucleotide and predicted amino acid changes in the N proteins of H1a and H1b viruses showed no evidence of selective pressure. This study investigated the genotype and cluster distribution of MeV in China over a 16-year period to establish a genetic baseline before MeV elimination in Western Pacific Region (WPR). Continuous and extensive MeV surveillance and the ability to quickly identify imported cases of measles will become more critical as measles elimination goals are achieved in China in the near future. This is the first report that a single endemic genotype of measles virus has been found to be continuously circulating in one country for at least 16 years.
PMCID: PMC3332093  PMID: 22532829

Results 1-3 (3)