Calculating the Number of Pregnant Women Receiving Standardized Services for PMTCT of HIV in Liangshan Prefecture, Based on the Equivalent Method.

OBJECTIVE: To calculate the number of pregnant women who receive standardized prevention of mother-to-child transmission (PMTCT) services for HIV annually. METHODS: HIV-positive pregnant women in six counties of Liangshan Prefecture in 2017 were selected as study subjects. The entire process, from when the subjects first received the PMTCT of HIV services to the end, was divided into four stages, which were further divided into 25 phases. The equivalent coefficient was used to indicate the weight of workload in each phase. Seven experts were invited to score the equivalent coefficient; the number of pregnant women who received standardized services to prevent the transmission of HIV was calculated. RESULTS: A total of 663 HIV-positive pregnant women were registered in six Liangshan Prefecture counties in 2017. This figure was converted into 7,780 person-months devoted to HIV-positive pregnant women, with 260 person-months (3.34%) spent on the first antenatal care, 1,510 person-months (19.41%) during pregnancy, 378 person-months (4.86%) on delivery, and 5,632 person-months (72.39%) on post-partum period. The equivalent coefficient calculation showed that 314 HIV-positive pregnant women received standardized PMTCT services. CONCLUSION: The number of pregnant women receiving standardized services for the PMTCT of HIV can be calculated accurately using the equivalent method to identify the gap between the level of PMTCT of HIV intervention services needed and the actual workload.

Vaccine-derived poliovirus surveillance in China during 2001-2013: the potential challenge for maintaining polio free status.

BACKGROUND: The goal of polio eradication is to complete elimination and containment of all wild, vaccine-related and Sabin polioviruses. Vaccine-derived poliovirus (VDPV) surveillance in China from 2001-2013 is summarized in this report, which has important implications for the global polio eradication initiative. METHODS: Acute flaccid paralysis (AFP) cases and their contacts with VDPVs isolated from fecal specimens were identified in our AFP surveillance system or by field investigation. Epidemiological and laboratory information for these children were analyzed and the reasons for the VDPV outbreak was explored. RESULTS: VDPVs were isolated from a total of 49 children in more than two-thirds of Chinese provinces from 2001-2013, including 15 VDPV cases, 15 non-polio AFP cases and 19 contacts of AFP cases or healthy subjects. A total of 3 circulating VDPVs (cVDPVs) outbreaks were reported in China, resulting in 6 cVDPVs cases who had not been vaccinated with oral attenuated poliomyelitis vaccine. Among the 4 immunodeficiency-associated VDPVs (iVDPVs) cases, the longest duration of virus excretion was about 20 months. In addition, one imported VDPV case from Myanmar was detected in Yunnan Province. CONCLUSIONS: Until all wild, vaccine-related and Sabin polioviruses are eradicated in the world, high quality routine immunization and sensitive AFP surveillance should be maintained, focusing efforts on underserved populations in high risk areas.

Impact of Influenza on Outpatient Visits, Hospitalizations, and Deaths by Using a Time Series Poisson Generalized Additive Model.

BACKGROUND: The disease burden associated with influenza in developing tropical and subtropical countries is poorly understood owing to the lack of a comprehensive disease surveillance system and information-exchange mechanisms. The impact of influenza on outpatient visits, hospital admissions, and deaths has not been fully demonstrated to date in south China. METHODS: A time series Poisson generalized additive model was used to quantitatively assess influenza-like illness (ILI) and influenza disease burden by using influenza surveillance data in Zhuhai City from 2007 to 2009, combined with the outpatient, inpatient, and respiratory disease mortality data of the same period. RESULTS: The influenza activity in Zhuhai City demonstrated a typical subtropical seasonal pattern; however, each influenza virus subtype showed a specific transmission variation. The weekly ILI case number and virus isolation rate had a very close positive correlation (r = 0.774, P < 0.0001). The impact of ILI and influenza on weekly outpatient visits was statistically significant (P < 0.05). We determined that 10.7% of outpatient visits were associated with ILI and 1.88% were associated with influenza. ILI also had a significant influence on the hospitalization rates (P < 0.05), but mainly in populations <25 years of age. No statistically significant effect of influenza on hospital admissions was found (P > 0.05). The impact of ILI on chronic obstructive pulmonary disease (COPD) was most significant (P < 0.05), with 33.1% of COPD-related deaths being attributable to ILI. The impact of influenza on the mortality rate requires further evaluation. CONCLUSIONS: ILI is a feasible indicator of influenza activity. Both ILI and influenza have a large impact on outpatient visits. Although ILI affects the number of hospital admissions and deaths, we found no consistent influence of influenza, which requires further assessment.

An outbreak following importation of wild poliovirus in Xinjiang Uyghur Autonomous Region, China, 2011.

BACKGROUND: After more than 10 years without a case of wild poliovirus (WPV) in China, an outbreak occurred in 2011 in Xinjiang Uyghur Autonomous Region. METHODS: Acute flaccid paralysis (AFP) case surveillance was strengthened with epidemiological investigations and specimen collection and serological surveys were conducted among hospitalized patients. RESULTS: There were 21 WPV cases and 23 clinical compatible polio cases reported. WPV was isolated from 14 contacts of AFP cases and 13 in the healthy population. Incidence of WPV and clinical compatible polio cases were both highest among children <1 years, however, 24/44 (54.5%) polio cases were reported among adults aged 15-39 years. CONCLUSIONS: High coverage of routine immunization should be maintained among children until WPV transmission is globally eradicated. Expansion of AFP case surveillance and use of serologic surveys to estimate population immunity should be conducted rapidly to guide preparedness and response planning for future WPV outbreaks.

Cross-border collaboration between China and Myanmar for emergency response to imported vaccine derived poliovirus case.

BACKGROUND: This report describes emergency response following an imported vaccine derived poliovirus (VDPV) case from Myanmar to Yunnan Province, China and the cross-border collaboration between China and Myanmar. Immediately after confirmation of the VDPV case, China disseminated related information to Myanmar with the assistance of the World Health Organization. METHODS: A series of epidemiological investigations were conducted, both in China and Myanmar, including retrospective searches of acute flaccid paralysis (AFP) cases, oral poliovirus vaccine (OPV) coverage assessment, and investigation of contacts and healthy children. RESULTS: All children <2 years of age had not been vaccinated in the village where the VDPV case had lived in the past 2 years. Moreover, most areas were not covered for routine immunization in this township due to vaccine shortages and lack of operational funds for the past 2 years. CONCLUSIONS: Cross-border collaboration may have prevented a potential outbreak of VDPV in Myanmar. It is necessary to reinforce cross-border collaboration with neighboring countries in order to maximize the leverage of limited resources.

An outbreak of type π vaccine-derived poliovirus in Sichuan province, China: emergence and circulation in an under-immunized population.

BACKGROUND: During August 2011-February 2012, an outbreak of type Π circulating vaccine-derived poliovirus (cVDPVs) occurred in Sichuan Province, China. METHODS: A field investigation of the outbreak was conducted to characterize outbreak isolates and to guide emergency response. Sequence analysis of poliovirus capsid protein VP1 was performed to determine the viral propagation, and a coverage survey was carried out for risk assessment. RESULTS: One clinical compatible polio case and three VDPV cases were determined in Ngawa County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province. Case patients were unimmunized children, 0.8-1 years old. Genetic sequencing showed that the isolates diverged from the VP1 region of the type Π Sabin strain by 5-12 nucleotides (nt) and shared the same 5 nt VP1 substitutions, which indicate single lineage of cVDPVs. Of the 7 acute flaccid paralysis cases (all>6 months) reported in Ngawa Prefecture in 2011, 4 (57.1%) cases (including 2 polio cases) did not receive oral attenuated poliovirus vaccine. Supplementary immunization activities (SIAs) were conducted in February-May, 2012, and the strain has not been isolated since. CONCLUSION: High coverage of routine immunization should be maintained among children until WPV transmission is globally eradicated. Risk assessments should be conducted regularly to pinpoint high risk areas or subpopulations, with SIAs developed if necessary.

Poliomyelitis eradication in China: 1953-2012.

BACKGROUND: Poliomyelitis has historically been endemic in China and has been considered an important cause of disability and death. METHODS: We reviewed strategies and measures of poliomyelitis control and eradication from 1953 to 2012. Data from notifiable disease and routine immunization reporting systems and acute flaccid paralysis (AFP) surveillance were analyzed. RESULTS: About 20 000 poliomyelitis cases were reported annually in the prevaccine era. During 1965-1977, live, attenuated oral poliomyelitis vaccine (OPV) was administered to children through annual mass campaigns in the winter, and the number of poliomyelitis cases started to decline. A cold chain system was established during 1982, and OPV coverage increased during the early stage of the Expanded Programme on Immunization, from 1978 to 1988. Between 1989 and 1999, routine immunization was strengthened, supplementary immunization activities (SIAs) were conducted, and the AFP surveillance system was established. China reported a last indigenous poliomyelitis case in 1994 and was certified as free of polio in 2000. To maintain its polio-free status, China kept >90% coverage of 3 doses of OPV, conducted SIAs in high-risk areas, and maintained high-quality of AFP surveillance. China succeeded in stopping the outbreak in Xinjiang in 2011. CONCLUSIONS: China's polio-free status was achieved and maintained through strengthening routine immunization and implementing SIAs and AFP surveillance.

Sero-survey of polio antibodies during wild poliovirus outbreak in southern Xinjiang Uygur Autonomous Region, China.

BACKGROUND: After being polio free for more than 10 years, an outbreak following importation of wild poliovirus (WPV) was confirmed in Xinjiang Uygur Autonomous Region, China, in 2011. METHODS: A cross-sectional study was conducted prior to supplementary immunization activities (SIAs), immediately after the confirmation of the WPV outbreak. In selected prefectures, participants aged ≤ 60 years old who visited hospitals at county-level or above to have their blood drawn for reasons not related to the study, were invited to participate in our study. Antibody titers ≥ 8 were considered positive. RESULTS: Among the 2,611 participants enrolled, 2,253 (86.3%), 2,283 (87.4%), and 1,989 (76.2%) were seropositive to P1, P2 and P3 respectively, and 1744 (66.8%) participants were seropositive to all the three serotypes. Lower antibody seropositivities and geometric mean titers were observed in children <1 year of age and in adults aged 15-39 years. CONCLUSION: Serosurveys to estimate population immunity in districts at high risk of polio importation might be useful to gauge underlying population immunity gaps to polio and possibly to guide preparedness and response planning. Consideration should be given to older children and adults during polio risk assessment planning and outbreak response.

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

BACKGROUND: After 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. METHODS: To 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. RESULTS: Totally, 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. CONCLUSIONS: Incorporating 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 and control of a poliomyelitis outbreak in Xinjiang, China.

BACKGROUND: The last case of infection with wild-type poliovirus indigenous to China was reported in 1994, and China was certified as a poliomyelitis-free region in 2000. In 2011, an outbreak of infection with imported wild-type poliovirus occurred in the province of Xinjiang. METHODS: We conducted an investigation to guide the response to the outbreak, performed sequence analysis of the poliovirus type 1 capsid protein VP1 to determine the source, and carried out serologic and coverage surveys to assess the risk of viral propagation. Surveillance for acute flaccid paralysis was intensified to enhance case ascertainment. RESULTS: Between July 3 and October 9, 2011, investigators identified 21 cases of infection with wild-type poliovirus and 23 clinically compatible cases in southern Xinjiang. Wild-type poliovirus type 1 was isolated from 14 of 673 contacts of patients with acute flaccid paralysis (2.1%) and from 13 of 491 healthy persons who were not in contact with affected persons (2.6%). Sequence analysis implicated an imported wild-type poliovirus that originated in Pakistan as the cause of the outbreak. A public health emergency was declared in Xinjiang after the outbreak was confirmed. Surveillance for acute flaccid paralysis was enhanced, with daily reporting from all public and private hospitals. Five rounds of vaccination with live, attenuated oral poliovirus vaccine (OPV) were conducted among children and adults, and 43 million doses of OPV were administered. Trivalent OPV was used in three rounds, and monovalent OPV type 1 was used in two rounds. The outbreak was stopped 1.5 months after laboratory confirmation of the index case. CONCLUSIONS: The 2011 outbreak in China showed that poliomyelitis-free countries remain at risk for outbreaks while the poliovirus circulates anywhere in the world. Global eradication of poliomyelitis will benefit all countries, even those that are currently free of poliomyelitis.

Circulating serum trefoil factor 3 (TFF3) is dramatically increased in chronic kidney disease.

OBJECTIVES: Trefoil factor 3 (TFF3) is a small peptide that plays an important role in mucosal protection, cell proliferation, and cell migration. The aberrant expression of TFF3 is correlated with gastrointestinal inflammation, solid tumors, and other clinical diseases. The objective of this study was to identify the distribution characteristics of serum TFF3 in common clinical diseases. MATERIALS AND METHODS: A large prospective randomized study of 1,072 Chinese patients was performed using an enzyme-linked immunosorbent assay (ELISA) to examine the serum TFF3 concentrations in patients with different diseases. A matched case-control study was conducted on patients with chronic kidney disease (CKD) stages 1-5. Immunohistochemistry (IHC) was performed using renal tissues to determine the relationship between the severity of CKD and the serum and urine concentrations of TFF3 peptides. RESULTS: The mean serum concentrations of TFF3 in patients with CKD, metastatic and secondary carcinoma (MC) and acute gastroenteritis (AG) (200.9 ng/ml, 95.7 ng/ml and 71.7 ng/ml, respectively) were significantly higher than those in patients with other common clinical diseases. A positive correlation tendency was observed between the serum TFF3 concentrations and the severity of CKD. The mean serum TFF3 values for CKD stages 1-5 were 23.6 ng/ml, 29.9 ng/ml, 54.9 ng/ml, 85.0 ng/ml and 176.6 ng/ml, respectively. The same trend was observed in the urine TFF3 concentrations and the CKD stages. The creatinine(Cr)-corrected concentrations of TFF3 in urine were 367.1 ng/mg·Cr, 910.6 ng/mg·Cr, 1,149.0 ng/mg·Cr, 1,610.0 ng/mg·Cr and 3,475.0 ng/mg·Cr for CKD stages 1-5, respectively. IHC revealed that TFF3 expression was concentrated in tubular epithelial cells. CONCLUSIONS: The influence of kidney injuries must be fully considered when performing clinical TFF3 research. Further studies on TFF3 in CKD will contribute to our understanding of its pathological roles and mechanisms in other diseases.

[The method and efficacy for screening neonatal tetanus in high risk areas in China].

OBJECTIVES: To establish a method for screening neonatal tetanus (NT) in high risk areas in China using multi-sources data. METHODS: We adopted six NT-related indicators from National Notifiable Disease Report System (NNDRS) and National Maternal and Child Health Annual Report System, to calculate weighted high-risk score at prefecture level in 2010 and 2011. And we selected the top 30 high risk cities, and compared the scores with the actual NT incidence ranking and WHO scoring. RESULTS: The highest areas distributed in the Southwest of China with poor and minority population, and the Southeast part with high density of migrants. In the leading 30 prefectures with high score between the methods of weighted high-risk scoring and reported NT incidence ranking, there were 8 different. In comparison of the results of the methods of weighed high-risk scoring and WHO scoring, 276 prefectures in 340 distributed were divided into the same ranking groups, with Kappa coefficient 0.56 (P < 0.01). The Chi-Square association coefficient was 0.74 (P < 0.01), which showed a high correlation. But there were 10 different prefectures in the leading 36 prefectures between the two methods. CONCLUSION: The weighted scoring method included several possible factors influencing NT incidence and took their weights into consideration. Thereby, compared with WHO scoring method, this method could be more appropriate for the reality in China.

Genotype v Japanese encephalitis virus is emerging.

Japanese encephalitis (JE) is a global public health issue that has spread widely to more than 20 countries in Asia and has extended its geographic range to the south Pacific region including Australia. JE has become the most important cause of viral encephalitis in the world. Japanese encephalitis viruses (JEV) are divided into five genotypes, based on the nucleotide sequence of the envelope (E) gene. The Muar strain, isolated from patient in Malaya in 1952, is the sole example of genotype V JEV. Here, the XZ0934 strain of JEV was isolated from Culex tritaeniorhynchus, collected in China. The complete nucleotide and amino acid sequence of XZ0934 strain have been determined. The nucleotide divergence ranged from 20.3% to 21.4% and amino acid divergence ranged from 8.4% to 10.0% when compared with the 62 known JEV isolates that belong to genotype I-IV. It reveals low similarity between XZ0934 and genotype I-IV JEVs. Phylogenetic analysis using both complete genome and structural gene nucleotide sequences demonstrates that XZ0934 belongs to genotype V. This, in turn, suggests that genotype V JEV is emerging in JEV endemic areas. Thus, increased surveillance and diagnosis of viral encephalitis caused by genotype V JEV is an issue of great concern to nations in which JEV is endemic.

Safety of influenza A (H1N1) vaccine in postmarketing surveillance in China.

BACKGROUND: On 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. METHODS: We 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 System's National Adverse Event Following Immunization Surveillance System. Data were collected through March 21, 2010, and were verified and analyzed by the Chinese CDC. RESULTS: A 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. CONCLUSIONS: No 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.

[A sero-epidemiological study on hepatitis C in China].

OBJECTIVE: To better understand and measure the status of hepatitis C virus (HCV) infection, we conducted a sero-epidemiological study using the remaining blood samples and data of the nationwide survey of hepatitis B in Chinese residents which was carried out in 2006. METHODS: The anti-HCV reagent was screened out from the reagents by the HCV infection blood serum plate with anti-HCV positives or negatives. This plate recognized the Murex 3.0 and Ortho 3.0 reagents as gold standards. Anti-HCV in the blood samples were tested using this reagent and confirmed by Chiron HCV RIBA 3.0 reagents. RESULTS: Among the population aged 1 year to 59 year-olds, the overall prevalence rate of anti-HCV was 0.43% (95%CI: 0.33% - 0.53%), with the rates of anti-HCV among males and females as 0.46% and 0.40%, respectively. The prevalence rate of anti-HCV in urban area was 0.43%, and in rural area it was 0.43%. The prevalence rate of anti-HCV in the Eastern, Middle and Western areas were 0.37% (95%CI: 0.21% - 0.53%), 0.67% (95%CI: 0.40% - 0.94%) and 0.31% (95%CI: 0.20% - 0.42%) respectively. The prevalence rates of anti-HCV for the three areas did not show significant differences, statistically. The prevalence rate of anti-HCV in the South and North areas were 0.29% (95%CI: 0.21% - 0.52%) and 0.53% (95%CI: 0.38% - 0.64%) respectively. CONCLUSION: Our data revealed that China was in the low prevalence area for hepatitis C infection and the results also suggested that the comprehensive measures for HCV control and prevention had been successfully achieved in the country.

[Progress on rubella control and immunization strategies].

Rubella is one of the global public health problems, and the main harm is CRS which derives from pregnant women that infected rubella virus in the first pregnant periods. CRS could cause great economic burden to society. In order to decrease the incidence of Rubella and CRS, China has integrated MMR into Expanded Program on Immunization (EPI) in 2007. This article will provide some ideas on Rubella vaccine into EPI. The paper will review the rubella vaccine immunigation Strategy both at home and abroad.

[Epidemiological analysis of imported cases of dengue fever in Guangdong province and Hong Kong during 2004-2006 in China].

OBJECTIVE: To analyze the epidemiological characteristics of imported cases of dengue fever in Guangdong province (GD) and in Hong Kong (HK) during 2004-2006 to provide evidence for further cooperation in the prevention and control programs on dengue fever in the two places. METHODS: Descriptive statistical analysis was performed on data obtained from dengue fever surveillance and reporting network in GD and from Centre for Health Protection, Department of Health, HK. RESULTS: Both from GD and HK 44 and 93 imported cases of Dengue fever were reported during 2004-2006. Most patients from GD acquired their infection from Singapore (13 cases), Indonesia (9 cases) or Cambodia (6 cases) while patients in HK mainly were imported from Indonesia (31 cases), the Philippines (16 cases) and Thailand (15 cases). The peak seasons of the two places were both from July to September. During the non-peak season period, the number of cases in Hong Kong was higher than that in Guangdong. Male/ female ratio was 1.2:1 in GD and 1.1:1 in HK. Age of patients in GD appeared to range from 6-80 years, with 63.6% (28/44) of them aged 20-39 years. 40.9% (18/44) of the cases were engaged in business, services, housework or unemployed. Those cases in HK were between 10-72 years of age, with 63.6% (28/ 44) of them aged 20-39 years while 47.3% (44/93) of the patients were with the occupation of business, services and industry. More cases in GD had a onset of disease before entering the border (27:17) than the cases in HK (35:57). The average time interval between onset and diagnosis were 7 and 9 days for GD and HK respectively. CONCLUSION: Frequent travel between Southeast Asia in summer among the working class appeared to be the main factor, causing imported cases of dengue fever in GD and HK. It is crucial to provide health education targeted at these high risk groups in order to prevent importation of dengue fever in the two areas.

[Meta-analysis on serological effect of the primary vaccination for Japanese encephalitis of the literatures].

OBJECTIVES: To summary and compare the different seroconversion rates after the primary vaccination for the Japanese encephalitis (JE), and to evaluate the serological effect of 3 kinds of JE vaccines. METHOD: Searching "CHKD", "Wanfang" database and "EMCC" databases, the studies of the immunogenicity after the primary JEV vaccination, all randomized controlled trials or non-randomized controlled trials were included, and statistical analysis were made by RevMan 4.2.10 software. RESULTS: A total of 12 literatures were included, 7 studies had control groups. The seroconversion rates after the primary vaccination, JEV-L, JEV-I (Vero) and JEV-I (PHK), were 86% (95% CI: 80%-91%), 83% (95% CI: 72% -94%) and 64% (95% CI: 58%-69%) respectively. Comparing the seroconversion rates of the 3 kinds of vaccines after primary immunization, the rate of JEV-I (Vero) was significantly higher than the rate of JEV-I (PHK), other comparisons were no significant difference. CONCLUSION: The serological effects of JEV-L and JEV-I (Vero) after the primary vaccination were higher than that of JEV-I (PHK).