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1.
MMWR Morb Mortal Wkly Rep ; 68(48): 1112-1116, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31805034

RESUMO

In 2005, the World Health Organization (WHO) Western Pacific Region countries, including China, resolved to eliminate measles by 2012 or as soon as feasible thereafter (1). As of 2018, nine* of the 37 Western Pacific Region countries or areas† had eliminated§ measles. China's Measles Elimination Action Plan 2006-2012 included strengthening routine immunization; conducting measles risk assessments, followed by supplementary immunization activities (SIAs) with measles-containing vaccine (MCV) at national and subnational levels; strengthening surveillance and laboratory capacity; and investigating and responding to measles outbreaks. Most recently, progress toward measles elimination in China was described in a 2014 report documenting measles elimination efforts in China during 2008-2012 and a resurgence in 2013 (2). This report describes progress toward measles elimination in China during January 2013-June 2019.¶ Measles incidence per million persons decreased from 20.4 in 2013 to 2.8 in 2018; reported measles-related deaths decreased from 32 in 2015 to one in 2018 and no deaths in 2019 through June. Measles elimination in China can be achieved through strengthening the immunization program's existing strategy by ensuring sufficient vaccine supply; continuing to improve laboratory-supported surveillance, outbreak investigation and response; strengthening school entry vaccination record checks; vaccinating students who do not have documentation of receipt of 2 doses of measles-rubella vaccine; and vaccinating health care professionals and other adults at risk for measles.


Assuntos
Erradicação de Doenças , Surtos de Doenças/prevenção & controle , Sarampo/prevenção & controle , Vigilância da População , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Feminino , Humanos , Programas de Imunização , Incidência , Lactente , Masculino , Sarampo/epidemiologia , Sarampo/mortalidade , Vacina contra Sarampo/administração & dosagem
2.
Hum Vaccin Immunother ; : 1-10, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31589548

RESUMO

Influenza vaccination coverage in pregnant women in China remains low. In this review, we first provide an overview of the evidence for the use of influenza vaccination during pregnancy. Second, we discuss influenza vaccination policy and barriers to increased seasonal influenza vaccination coverage in pregnant women in China. Third, we provide case studies of successes and challenges of programs for increasing seasonal influenza vaccination in pregnant women from other parts of Asia with lessons learned for China. Finally, we assess opportunities and challenges for increasing influenza vaccination coverage among pregnant women in China.

3.
Vaccine ; 37(35): 4928-4936, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31326253

RESUMO

BACKGROUND: The pace of global progress must increase if the Global Vaccine Action Plan (GVAP) goals are to be achieved by 2020. We administered a two-phase survey to key immunization stakeholders to assess the utility and application of GVAP, including how it has impacted country immunization programs, and to find ways to strengthen the next 10-year plan. METHODS: For the Phase I survey, an online questionnaire was sent to global immunization stakeholders in summer 2017. The Phase II survey was sent to regional and national immunization stakeholders in summer 2018, including WHO Regional Advisors on Immunization, Expanded Programme on Immunization managers, and WHO and UNICEF country representatives from 20 countries. Countries were selected based on improvements (10) versus decreases (10) in DTP3 coverage from 2010 to 2016. RESULTS: Global immunization stakeholders (n = 38) cite global progress in improving vaccine delivery (88%) and engaging civil society organizations as advocates for vaccines (83%). Among regional and national immunization stakeholders (n = 58), 70% indicated reaching mobile and underserved populations with vaccination activities as a major challenge. The top ranked activities for helping country programs achieve progress toward GVAP goals include improved monitoring of vaccination coverage and upgrading disease surveillance systems. Most respondents (96%) indicated GVAP as useful for determining immunization priorities and 95% were supportive of a post-2020 GVAP strategy. CONCLUSIONS: Immunization stakeholders see GVAP as a useful tool, and there is cause for excitement as the global immunization community looks toward the next decade of vaccines. The next 10-year plan should attempt to increase political will, align immunization activities with other health system agendas, and address important issues like reaching mobile/migrant populations and improving data reporting systems.

4.
Infect Dis Poverty ; 8(1): 57, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31269994

RESUMO

BACKGROUND: Mother to child transmission of hepatitis B virus (HBV) remains the most common form of HBV infection in China. Prevention of HBV vertical transmission involves timely administration of the complete hepatitis B vaccine (HepB) series and hepatitis B immunoglobulin. Post-vaccination serological testing (PVST) is utilized to determine an infant's outcome after HBV exposure and completion of HepB series. We aim to determine the frequency of compliance with a PVST testing cascade for HBV infected mothers and analyze factors associated with infant lost to follow up (LTFU). METHODS: We conducted a retrospective cohort review of previously collected data in Fujian, Jiangxi, Zhejiang and Chongqing provinces in China from 1 June 2016-31 December 2017. The study population included all HBV-exposed infants and their mothers. SAS software was used for statistical analyses. Bivariate and multivariate regression analyses (presented in odds ratio [OR] with 95% confidence intervals [CI]) were used to compare the proportional differences of factors associated with PVST not being completed. RESULTS: Among enrolled 8474 target infants, 40% of them transferred out of the study provinces without further information and 4988 were eligible for PVST. We found 20% (994) of infants were not compliant with the testing cascade: 55% of LTFU occurred because parents refused venous blood sample collection or failure of sample collection in the field, 16% transferred out after 6 months of age, and 10% of families chose to have independent, confidential PVST completed without reporting results. High PVST noncompliance rates were more likely to be from Fujian (aOR = 17.0, 95% CI: 9.7-29.9), Zhejiang (aOR = 5.7, 95% CI: 3.2-10.1) and Jiangxi (aOR = 1.9, 95% CI: 1.0-3.4), and from HBV e antigen positive mother (aOR = 1.2, 95% CI: 1.1-1.4). CONCLUSIONS: This study found that the LTFU rate reached 20% in PVST program, which was a significant problem. We recommend implementing a national electronic information system for tracking HBV at risk mother-infant pairs; encourage further research in developing a less invasive means of completing PVST, and take effective measures nationally to reduce HBV stigma. Without reducing the loss to follow up rate among infants eligible for PVST, elimination of vertical HBV transmission will be impossible.


Assuntos
Vírus da Hepatite B/fisiologia , Hepatite B/tratamento farmacológico , Cooperação do Paciente/estatística & dados numéricos , Testes Sorológicos/estatística & dados numéricos , Vacinação/estatística & dados numéricos , China , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Perda de Seguimento , Masculino , Estudos Retrospectivos
6.
Int J Epidemiol ; 48(4): 1240-1251, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30977801

RESUMO

BACKGROUND: Measles is among the most highly infectious human diseases. By virtue of increasingly effective childhood vaccination, together with targeted supplemental immunization activities (SIAs), health authorities in the People's Republic of China have reduced measles' reproduction number from about 18 to 2.3. Despite substantial residual susceptibility among young adults, more in some locales than others, sustained routine childhood immunization likely would eliminate measles eventually. To support global eradication efforts, as well as expedite morbidity and mortality reductions in China, we evaluated alternative SIAs via mechanistic mathematical modelling. METHODS: Our model Chinese population is stratified by immune status (susceptible to measles infection; infected, but not yet infectious; infectious; and recovered or immunized), age (0, 1-4, 5-9, …, 65+ years) and location (31 provinces). Contacts between sub-populations are either empirical or a mixture of preferential and proportionate with respect to age and decline exponentially with distance between locations at age-dependent rates. We estimated initial conditions and most parameters from recent cross-sectional serological surveys, disease surveillance and demographic observations. Then we calculated the reproduction numbers and gradient of the effective number with respect to age- and location-specific immunization rates. We corroborated these analytical results by simulating adolescent and young adult SIAs using a version of our model in which the age-specific contact rates vary seasonally. RESULTS: Whereas the gradient indicates that vaccinating young adults generally is the optimal strategy, simulations indicate that a catch-up campaign among susceptible adolescent schoolchildren would accelerate elimination, with timing dependent on uptake. CONCLUSIONS: These results are largely due to indirect effects (i.e. fewer infections than immunized people might otherwise cause), which meta-population models with realistic mixing are uniquely capable of reproducing accurately.

7.
Lancet Infect Dis ; 19(4): 402-409, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30833160

RESUMO

BACKGROUND: In China, measles-rubella vaccine and live attenuated SA 14-14-2 Japanese encephalitis vaccine (LJEV) are recommended for simultaneous administration at 8 months of age, which is the youngest recommended age for these vaccines worldwide. We aimed to assess the effect of the co-administration of these vaccines at 8 months of age on the immunogenicity of measles-rubella vaccine. METHODS: We did a multicentre, open-label, non-inferiority, two-group randomised controlled trial in eight counties or districts in China. We recruited healthy infants aged 8 months who had received all scheduled vaccinations according to the national immunisation recommendations and who lived in the county of the study site. Enrolled infants were randomly assigned (1:1) to receive either measles-rubella vaccine and LJEV simultaneously (measles-rubella plus LJEV group) or measles-rubella vaccine alone (measles-rubella group). The primary outcome was the proportion of infants with IgG antibody seroconversion for measles 6 weeks after vaccination, and a secondary outcome was the proportion of infants with IgG antibody seroconversion for rubella 6 weeks after vaccination. Analyses included all infants who completed the study. We used a 5% margin to establish non-inferiority. This trial was registered at ClinicalTrials.gov (NCT02643433). FINDINGS: 1173 infants were assessed for eligibility between Aug 13, 2015, and June 10, 2016. Of 1093 (93%) enrolled infants, 545 were randomly assigned to the measles-rubella plus LJEV group and 548 to the measles-rubella group. Of the infants assigned to each group, 507 in the measles-rubella plus LJEV group and 506 in the measles-rubella group completed the study. Before vaccination, six (1%) of 507 infants in the measles-rubella plus LJEV group and one (<1%) of 506 in the measles-rubella group were seropositive for measles; eight (2%) infants in the measles-rubella plus LJEV group and two (<1%) in the measles-rubella group were seropositive for rubella. 6 weeks after vaccination, measles seroconversion in the measles-rubella plus LJEV group (496 [98%] of 507) was non-inferior to that in the measles-rubella group (499 [99%] of 506; difference -0·8% [90% CI -2·6 to 1·1]) and rubella seroconversion in the measles-rubella plus LJEV group (478 [94%] of 507) was non-inferior to that in the measles-rubella group (473 [94%] of 506 infants; difference 0·8% [90% CI -1·8 to 3·4]). There were no serious adverse events in either group and no evidence of a difference between the two groups in the prevalence of any local adverse event (redness, rashes, and pain) or systemic adverse event (fever, allergy, respiratory infections, diarrhoea, and vomiting). Fever was the most common adverse event (97 [19%] of 507 infants in the measles-rubella plus LJEV group; 108 [21%] of 506 infants in the measles-rubella group). INTERPRETATION: The evidence of similar seroconversion and safety with co-administered LJEV and measles-rubella vaccines supports the co-administration of these vaccines to infants aged 8 months. These results will be important for measles and rubella elimination and the expansion of Japanese encephalitis vaccination in countries where it is endemic. FUNDING: US Centers for Disease Control and Prevention, US Department of Health and Human Services; China-US Collaborative Program on Emerging and Re-emerging Infectious Diseases.

8.
BMC Infect Dis ; 18(1): 502, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30286735

RESUMO

BACKGROUND: Vaccine regulation in China meets World Health Organization standards, but China's vaccine industry and immunization program have some characteristics that differ from other countries. We described the history, classification, supply and prices of vaccines available and used in China, compared with high-and middle-incomes countries to illustrate the development of Chinese vaccine industry and immunization program. METHODS: Immunization policy documents were obtained from the State Council and the National Health and Family Planning Commission (NHFPC). Numbers of doses of vaccines released in China were obtained from the Biologicals Lot Release Program of the National Institutes for Food and Drug Control (NIFDC). Vaccine prices were obtained from Chinese Central Government Procurement (CCGP). International data were collected from US CDC, Public Health England, European CDC, WHO, and UNICEF. RESULTS: Between 2007 and 2015, the annual supply of vaccines in China ranged between 666 million and 1,190 million doses, with most doses produced domestically. The government's Expanded Program on Immunization (EPI) prevents 12 vaccine preventable diseases (VPD) through routine immunization. China produces vaccines that are in common use globally; however, the number of routinely-prevented diseases is fewer than in high- and middle-income countries. Contract prices for program (EPI) vaccines ranged from 0.1 to 5.7 US dollars per dose - similar to UNICEF prices. Contract prices for private-market vaccines ranged from 2.4 to 102.9 US dollars per dose - often higher than prices for comparable US, European, and UNICEF vaccines. CONCLUSION: China is a well-regulated producer of vaccines, but some vaccines that are important globally are not included in China's EPI system in China. Sustained and coordinated effort will be required to bring Chinese vaccine industry and EPI into an era of global leadership.


Assuntos
Assistência à Saúde , Vacinação/estatística & dados numéricos , Vacinas/economia , China , Controle de Doenças Transmissíveis , História do Século XX , História do Século XXI , Humanos , Programas de Imunização/economia , Programas de Imunização/história , Programas de Imunização/estatística & dados numéricos , Vacinação/classificação , Vacinação/história , Vacinas/imunologia , Vacinas/provisão & distribução
9.
Emerg Infect Dis ; 24(7): 1178-1187, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29916350

RESUMO

The need for closer linkages between scientific and programmatic areas focused on addressing vaccine-preventable and acute respiratory infections led to establishment of the National Center for Immunization and Respiratory Diseases (NCIRD) at the Centers for Disease Control and Prevention. During its first 10 years (2006-2015), NCIRD worked with partners to improve preparedness and response to pandemic influenza and other emergent respiratory infections, provide an evidence base for addition of 7 newly recommended vaccines, and modernize vaccine distribution. Clinical tools were developed for improved conversations with parents, which helped sustain childhood immunization as a social norm. Coverage increased for vaccines to protect adolescents against pertussis, meningococcal meningitis, and human papillomavirus-associated cancers. NCIRD programs supported outbreak response for new respiratory pathogens and oversaw response of the Centers for Disease Control and Prevention to the 2009 influenza A(H1N1) pandemic. Other national public health institutes might also find closer linkages between epidemiology, laboratory, and immunization programs useful.


Assuntos
Doenças Respiratórias/epidemiologia , Doenças Respiratórias/prevenção & controle , Vacinação , Vacinas , Saúde Global , História do Século XXI , Humanos , Programas de Imunização , Doenças Respiratórias/história , Estados Unidos/epidemiologia , Vacinação/métodos , Vacinas/imunologia
10.
Vaccine ; 36(21): 3041-3047, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29685593

RESUMO

OBJECTIVE: To 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. METHODS: The 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. RESULTS: Total direct costs were $92.42 for each child fully immunized ($4.20/dose), which equates to $1529.55 million per birth cohort. RI costs were higher in the eastern region than in the western region, and higher than that of the central region. Vaccination coverage was positively associated with direct routine immunization costs. The cost of the recommended vaccines was $19.08/child and vaccine only accounted for 20.64% of total costs. Operational cost, including surveillance, communication, training and supervision, was $217.31/child, accounting for 14.21% of total cost. The indirect cost per child was $72.86; the total indirect cost was $1205.83 million for the birth cohort. Government investment in RI accounted for about 70% of total costs. Revenue from sales of private-sector vaccine supported the remaining 30% of RI costs. CONCLUSIONS: While government financing has increased, some operating costs continue to be provided from revenue generated by sales of Category 2 (private-sector) vaccines to families. China could benefit from bringing new and underutilized vaccines into the EPI system based on evidence that includes routine immunization vaccine and operations costs.


Assuntos
Financiamento de Capital , Programas de Imunização/economia , Adolescente , Criança , Pré-Escolar , China , Política de Saúde , Humanos , Lactente , Recém-Nascido
11.
Vaccine ; 36(17): 2307-2313, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29567035

RESUMO

BACKGROUND: Hepatitis B virus (HBV) can cause chronic HBV infection, which may lead to advanced cirrhosis and liver cancer. Healthcare workers (HCWs) are at risk HBV infection as an occupational hazard. Hepatitis B vaccination of HCWs is recommended by WHO, but the status of hepatitis B vaccination among HCWs in China is seldom reported. METHODOLOGY: We conducted a cross-sectional study in 22 hospitals of 3 developed cities in China. We interviewed managers in infectious diseases and occupational health departments, and at least 40 HCWs per hospital. RESULTS: We interviewed 929 HCWs; 80.8% were vaccinated against hepatitis B and 96.7% were willing to be vaccinated; 38.2% of HCWs reported having at least one needle stick or sharps injury. Three hospitals provide free hepatitis B vaccination for HCWs; hospitals with a hepatitis B vaccination policy, more HCWs reported being vaccinated (91.7% vs 79.0%, P < 0.001). HCWs in high risk departments (P = 0.011), with more knowledge of hepatitis B vaccine (P < 0.001), and with fewer working years (P = 0.002) were more likely to be vaccinated against HBV. Infectious diseases and occupational health managers had positive attitudes towards hepatitis B vaccination. CONCLUSIONS: Hepatitis B vaccination was well accepted among HCWs. Hospital provision of free vaccine, greater HCW knowledge of HBV, and working in higher-risk settings were associated with being vaccinated. A national policy of offering hepatitis B vaccine to HCWs should be considered in China. Provision of free hepatitis B vaccine for HBsAb negative HCWs may be acceptable. Education about HBV and hepatitis B vaccine may help promote policy implementation.


Assuntos
Pessoal de Saúde/estatística & dados numéricos , Vacinas contra Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Hepatite B/prevenção & controle , Vacinação/estatística & dados numéricos , Adolescente , Adulto , China , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/prevenção & controle , Inquéritos e Questionários , Adulto Jovem
12.
BMC Infect Dis ; 18(1): 36, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29329528

RESUMO

BACKGROUND: As China approaches the elimination of measles, outbreaks of measles continue to occur. Healthcare workers (HCWs) are known to be at high risk of infection and transmission of measles virus. A measles outbreak occurred in a hospital in Xinjiang Uighur Autonomous Region of the People's Republic of China. We report an investigation of this outbreak and its implications for measles elimination and outbreak preparedness. METHODS: We conducted a retrospective search for measles cases using hospital records. Information on cases was collected by interview, and was used to determine epidemiological linkages. We surveyed HCWs to determine their demographic characteristics, disease history and vaccination status, and knowledge about measles. RESULTS: We identified 19 cases, ages 18 to 45 years, in Hospital W between December 2015 and January 2016; 14 were laboratory-confirmed, and 5 were epidemiologically linked. The primary case was a 25-year-old neurology department nurse who developed a rash on 22 December 2015 that was reported on 11 January 2016. She continued working and living with her workmates in a dormitory during her measles transmission period. Among the 19 infected HCWs, 2 had received a dose of measles-containing vaccine (MCV) before the outbreak, and 16 had unknown vaccination status. Outbreak response immunization activities were started on 8 January in a non-selective manner by offering vaccine regardless of vaccination history; 605(68%) of 890 HCWs were vaccinated. The HCW survey had a 73% response rate (646/890); 41% of HCWs reported that they had received MCV before outbreak, and 56% exhibited good knowledge of measles symptoms, transmission, complications, and vaccination. CONCLUSIONS: Low MCV coverage, low measles knowledge among HCWs, delayed reporting of measles cases, and absence of proper case management were associated with this outbreak. Training and vaccinating HCWs against measles are essential activities to prevent measles virus transmission among HCWs.


Assuntos
Pessoal de Saúde , Sarampo/transmissão , Adulto , China/epidemiologia , Surtos de Doenças , Exantema/virologia , Feminino , Hospitais , Habitação , Humanos , Masculino , Sarampo/epidemiologia , Vacina contra Sarampo/administração & dosagem , Pessoa de Meia-Idade , Doenças Profissionais/epidemiologia , Estudos Retrospectivos , Vacinação/estatística & dados numéricos , Adulto Jovem
13.
Vaccine ; 34(51): 6539-6544, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-27329182

RESUMO

INTRODUCTION: Following implementation of China's 2006-2012 Action Plan for measles elimination, which led to a nadir of measles in 2012, a resurgence started in 2013 that continued into 2014. Measles typically is a disease that mainly affects children. We investigated a community outbreak in 2014 with measles virus transmission among adults without children serving as virus reservoirs. Our investigation highlights adult susceptibility to measles. METHODS: We conducted a retrospective active case search, and analyzed confirmed case data to describe person, place, and time characteristics of the outbreak. All individuals with measles with onset during the first 2 months of the outbreak were interviewed face-to-face to determine source(s) of infection and transmission route (from whom and to whom). RESULTS: Among the 280 cases, 220 (77.6%) were among ≥20-year-old adults, 24 (8.6%) were among 8-23 month olds, 22 (7.9%) were among <8-month-old infants, and the remaining 14 (5.9%) were among 2-19 year olds. Of the 83 cases in the early stage of the outbreak, 41 (49.4%) were acquired in the community, 24 (28.9%) were acquired nosocomially, 13 (15.7%) were acquired by family contact, and 5 were imported. Among 44 clearly determined transmission linkages, 37 (84.1%) were adult to other age-group (these include 29 adult-to-adult, seven adult-to-child, and one adult-to-infant), six were from infants to adult and children, and one was child-to-child. Outbreak response immunization activities were implemented by non-selective supplementary immunization activities, with 51.3% of targeted 5-19-year-old children and adolescents, and 30.2% of targeted 20-49-year-old adults being vaccinated. CONCLUSIONS: Despite high population immunity among children and adolescents following three rounds of measles vaccine supplementary immunization activities, sustained measles virus transmission still occurred among adults in this community. Adult measles immunity gaps might threaten measles elimination, highlighting the importance targeting susceptible adults during outbreak response immunization.


Assuntos
Surtos de Doenças , Transmissão de Doença Infecciosa , Sarampo/epidemiologia , Sarampo/transmissão , Adolescente , Adulto , Criança , Pré-Escolar , China/epidemiologia , Reservatórios de Doenças , Suscetibilidade a Doenças , Feminino , Humanos , Lactente , Recém-Nascido , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
14.
Int J Epidemiol ; 45(2): 441-9, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-27174834

RESUMO

BACKGROUND: China reduced hepatitis B virus (HBV) infection by 90% among children under 5 years old with safe and effective hepatitis B vaccines (HepB). In December 2013, this success was threatened by widespread media reports of infant deaths following HepB administration. Seventeen deaths and one case of anaphylactic shock following HBV vaccination had been reported. METHODS: We conducted a telephone survey to measure parental confidence in HepB in eleven provinces at four points in time; reviewed maternal HBV status and use of HepB for newborns in birth hospitals in eight provinces before and after the event; and monitored coverage with hepatitis B vaccine and other programme vaccines in ten provinces. RESULTS: HepB from the implicated company was suspended during the investigation, which showed that the deaths were not caused by HepB vaccination. Before the event, 85% respondents regarded domestic vaccines as safe, decreasing to 26.7% during the event. During the height of the crisis, 30% of parents reported being hesitant to vaccinate and 18.4% reported they would refuse HepB. Use of HepB in the monitored provinces decreased by 18.6%, from 53 653 doses the week before the event to 43 688 doses during the week that Biokangtai HepB was suspended. Use of HepB within the first day of life decreased by 10% among infants born to HBsAg-negative mothers, and by 6% among infants born to HBsAg-positive mothers. Vaccine refusal and HepB birth dose rates returned to baseline within 2 months; confidence increased, but remained below baseline. CONCLUSIONS: The HBV vaccine event resulted in the suspension of a safe vaccine, which was associated with a decline of parental confidence, and refusal of vaccination. Suspension of a vaccine can lead to loss of confidence that is difficult to recover. Timely and credible investigation, accompanied by proactive outreach to stakeholders and the media, may help mitigate negative impact of future coincidental adverse events following immunization.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/mortalidade , Vacinas contra Hepatite B/efeitos adversos , Hepatite B/prevenção & controle , Programas de Imunização , Morte do Lactente , Vacinação , Sistemas de Notificação de Reações Adversas a Medicamentos , Causas de Morte , Criança , China/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etnologia , Feminino , Hepatite B/diagnóstico , Hepatite B/etnologia , Anticorpos Anti-Hepatite B/administração & dosagem , Anticorpos Anti-Hepatite B/efeitos adversos , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/imunologia , Humanos , Lactente , Recém-Nascido , Masculino , Meios de Comunicação de Massa , Inquéritos e Questionários , Vacinação/estatística & dados numéricos , Vacinação/tendências
15.
Vaccine ; 34(51): 6553-6560, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-27013438

RESUMO

INTRODUCTION: Endemic measles persists in China, despite >95% reported coverage of two measles-containing vaccine doses and nationwide campaign that vaccinated more than 100 million children in 2010. We performed a case-control study in six Chinese provinces during January 2012 through June 2013 to identify risk factors for measles infection among children aged 0-7 months. METHODS: Children with laboratory-confirmed measles were neighborhood matched with three controls. We interviewed parents of case and control infants on potential risk factors for measles. Adjusted matched odds ratios (mOR) and 95% confidence intervals (CIs) were calculated by multivariable conditional logistic modeling. We calculated attributable fractions for risk factors that could be interpreted as causal. RESULTS: Eight hundred thirty cases and 2303 controls were enrolled. In multivariable analysis, male sex (mOR 1.6 [1.3, 2.0]), age 5-7 months (mOR 3.9 [3.0, 5.1]), migration between counties (mOR 2.3 [1.6, 3.4]), outpatient hospital visits (mOR 9.4 [6.6, 13.3]) and inpatient hospitalization (mOR 107.1 [48.8, 235.1]) were significant risk factors. The calculated attributable fractions for hospital visits was 43.1% (95% CI: 40.1, 47.5%) adjusted for age, sex and migration. CONCLUSIONS: Hospital visitation was the largest risk factor for measles infection in infants. Improved hospital infection control practices would accelerate measles elimination in China.


Assuntos
Sarampo/epidemiologia , Estudos de Casos e Controles , China/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fatores de Risco
16.
Lancet Infect Dis ; 16(5): 599-605, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26852723

RESUMO

BACKGROUND: Vaccination programmes to prevent outbreaks after introductions of infectious people aim to maintain the average number of secondary infections per infectious person at one or less. We aimed to assess heterogeneity in vaccine uptake and other characteristics that, together with non-random mixing, could increase this number and to evaluate strategies that could mitigate their impact. METHODS: Because most US children attend elementary school in their own neighbourhoods, surveys of children entering elementary school (age 5 years before Sept 1) allow assessment of spatial heterogeneity in the proportion of children immune to vaccine-preventable diseases. We used data from a 2008 school-entry survey by the Immunization Division of the California Department of Public Health to obtain school addresses; numbers of students enrolled; proportions of enrolled students who had received one or two doses of the measles, mumps, and rubella (MMR) vaccine; and proportions with medical or personal-belief exemptions. Using a mixing model suitable for spatially-stratified populations, we projected the expected numbers of secondary infections per infectious person for measles, mumps, and rubella. We also mapped contributions to this number for measles in San Diego County's 638 elementary schools and its largest district, comprising 200 schools (31%). We then modelled the effect on measles' realised reproduction number (RV) of the following plausible interventions: vaccinating all children with personal-belief exemptions, increasing uptake by 10% to 50% in all low-immunity schools (<90% of students immune) or in only influential (effective daily contact rates >3 or contacts inter-school >30%) low-immunity schools, and increasing private school uptake to the public school average. FINDINGS: In 2008, 39 132 children began elementary school in San Diego County, CA, USA. At entry to school, 97% had received at least one dose of the MMR vaccine, with 2·5% having personal-belief exemptions. We note substantial heterogeneity in immunity throughout the county. Although the average population immunities for measles, mumps, and rubella (92%, 87%, 92%) were similar to the population-immunity thresholds in homogeneous, randomly-mixing populations (91%, 88%, 76%), after accounting for heterogeneity and non-random mixing, the basic reproduction numbers increased by 70%, meaning that introduced pathogens could cause outbreaks. The impact of our modelled interventions ranged from negligible to a nearly complete reduction in the outbreak potential of measles. The most effective intervention to lower the realised reproduction number (RV 3·39) was raising immunity by 50% in 114 schools with low immunity (RV 1·02), but raising immunity by this level in only influential, low-immunity schools also was effective (RV 2·02). The effectiveness of vaccinating the 972 children with personal-belief exemptions was similar to that of targeting all low-immunity schools (RV 1·11). Targeting only private schools had little effect. INTERPRETATION: Our findings suggest that increasing vaccine uptake could prevent outbreaks such as that of measles in San Diego in 2008. Vaccinating children with personal-belief exemptions was one of the most effective interventions that we modelled, but further research on mixing in heterogeneous populations is needed. FUNDING: None.


Assuntos
Surtos de Doenças/prevenção & controle , Imunização/estatística & dados numéricos , Vacina contra Sarampo-Caxumba-Rubéola/administração & dosagem , Sarampo/epidemiologia , Sarampo/prevenção & controle , Modelos Estatísticos , California , Criança , Pré-Escolar , Humanos , Instituições Acadêmicas , Vacinação/métodos
17.
Vaccine ; 34(51): 6545-6552, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-26876440

RESUMO

INTRODUCTION: Endemic measles persists in China, despite >95% reported coverage of two measles-containing vaccine doses and nationwide campaign that vaccinated more than 100 million children in 2010. In 2011, almost half of the 9943 measles cases in China occurred in children eligible for measles vaccination. We conducted a case-control study during 2012-2013 to identify risk factors for measles infection in children aged 8 months-14 years. METHODS: Children with laboratory-confirmed measles were age- and neighborhood-matched with three controls. We interviewed parents of case and control infants on potential risk factors for measles. We calculated adjusted matched odds ratios and 95% confidence intervals of risk factors. We calculated attributable fractions for risk factors that could be interpreted as causal and vaccine efficacy (VE) for the measles containing vaccine (MCV) used in the Chinese immunization program. RESULTS: In all, 969 case-patients and 2845 controls were enrolled. In multivariable analysis, lack of measles vaccination both overall (mOR 22.7 [16.6, 31.1] and when stratified by region (east region, mOR 74.2 [27.3, 202]; central/western regions mOR 17.4 [12.5, 24.3]), hospital exposure (mOR 63.0, 95% CI [32.8, 121]), and migration among counties (overall mOR 3.0 [2.3, 3.9]) were significant risk factors. The calculated VE was 91.9-96.1% for a single dose of MCV and 96.6-99.5% for 2 doses. CONCLUSIONS: Lack of vaccination was the leading risk factor for measles infection, especially in children born since the 2010 supplementary immunization activity. Reducing missed vaccination opportunities, improving immunization access for migrant children, and strengthening school/kindergarten vaccine checks are needed to strengthen the routine immunization program and maintain progress toward measles elimination in China.


Assuntos
Vacina contra Sarampo/administração & dosagem , Sarampo/epidemiologia , Sarampo/prevenção & controle , Vacinação/estatística & dados numéricos , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Lactente , Masculino , Fatores de Risco
18.
Emerg Infect Dis ; 21(3): 477-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25695536

RESUMO

In 2013, a resurgence of measles occurred in Beijing, China. The outbreaks occurred among adults and were associated with endemic genotype H1 and imported genotype D8 viruses. Migrant workers were disproportionately represented in the outbreaks; thus, vaccinating such workers against measles may be an effective strategy toward the elimination of this disease.


Assuntos
Surtos de Doenças , Vírus do Sarampo/genética , Sarampo/epidemiologia , Adulto , China/epidemiologia , Genótipo , Humanos , Sarampo/prevenção & controle , Sarampo/transmissão , Vírus do Sarampo/classificação , Vigilância da População
19.
BMC Infect Dis ; 15: 23, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25608672

RESUMO

BACKGROUND: China is approaching measles elimination, but indigenous measles still circulates. County L in China has reported measles-containing vaccine (MCV) coverage rates >95% since 2000. Despite high reported coverage, a large measles outbreak occurred among young children in L County. We measured MCV coverage using 5 different methods during an investigation on this outbreak and compared our estimates with reported rates. METHODS: Reported coverage rates are determined by aggregating clinic-based data across the county: doses administered in each clinic divided by the number of children registered in each clinic. Our methods estimated coverage for the 2010-2012 birth cohort, and were (1) administrative method: doses administered in clinics divided by the birth cohort recorded in the Statistical Year Book, (2) house-to-house convenience-sample survey of children living near cases, (3) vaccination clinic records review, (4) determination of a convenience sample of measles outbreak cases' vaccination statuses and using the field vaccine efficacy outbreak equation to estimate population coverage, and (5) a seroprevalence survey using a convenience sample of residual blood samples from hospitals. RESULTS: The measles outbreak totaled 215 cases, representing an incidence of 195.8 per million population. Our estimated MCV coverage rates were: (1) administrative method: 84.1%-87.0% for MCV1 and 80.3%-90.0% for MCV2, (2) in-house survey: 83.3% of 9-17 month children received MCV1, and 74.5% of 24-47 month children received MCV2, (3) clinic record review: 85.5% of 9-17 month children received MCV1, and 73.2% of 24-59 month children received MCV2, (4) field VE method: 83.6% of 9-47 month children received one or more MCV doses, and (5) serology: seropositive rates were <80% in the 12-17 and 18-23 month age cohorts. CONCLUSIONS: Compared with reported coverage >95%, our 5 coverage assessments all showed substantially lower coverage. China should evaluate guidelines for reporting vaccination coverage and identify feasible improvements to the assessment methods.


Assuntos
Surtos de Doenças/prevenção & controle , Vacina contra Sarampo/administração & dosagem , Sarampo/epidemiologia , Vacinação/estatística & dados numéricos , Adolescente , Criança , Serviços de Saúde da Criança , Pré-Escolar , China/epidemiologia , Feminino , Promoção da Saúde , Humanos , Lactente , Masculino , Sarampo/prevenção & controle , Estudos Soroepidemiológicos
20.
Bull World Health Organ ; 92(5): 340-7, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24839323

RESUMO

OBJECTIVE: To analyse the epidemiology of measles in China and determine the progress made towards the national elimination of the disease. METHODS: We analysed measles surveillance data - on the age, sex, residence and vaccination status of each case and the corresponding outcome, dates of onset and report and laboratory results - collected between January 2005 and October 2013. FINDINGS: Between 2005 and October 2013, 596 391 measles cases and 368 measles-related deaths were reported in China. Annual incidence, in cases per 100 000 population, decreased from 9.95 in 2008 to 0.46 in 2012 but then rose to more than 1.96 in 2013. The number of provinces that reported an annual incidence of less than one case per million population increased from one in 2009 to 15 in 2012 but fell back to one in 2013. Median case age decreased from 83 months in 2005 to 14 months in 2012 and 11 months in January to October 2013. Between 2008 and 2012, the incidence of measles in all age groups, including those not targeted for vaccination, decreased by at least 93.6%. However, resurgence started in late 2012 and continued into 2013. Of the cases reported in January to October 2013, 40% were aged 8 months to 6 years. CONCLUSION: Although there is evidence of progress towards the elimination of measles from China, resurgence in 2013 indicated that many children were still not being vaccinated on time. Routine immunization must be strengthened and the remaining immunity gaps need to be identified and filled.


Assuntos
Sarampo/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Criança , Pré-Escolar , China/epidemiologia , Erradicação de Doenças , Notificação de Doenças , Surtos de Doenças/prevenção & controle , Feminino , Genótipo , Humanos , Incidência , Lactente , Masculino , Sarampo/mortalidade , Sarampo/prevenção & controle , Vacina contra Sarampo , Vírus do Sarampo/genética , Vigilância da População , Distribuição por Sexo , Adulto Jovem
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