An Observational Prospective Cohort Study of Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 Infection of an Aerosolized, Inhaled Adenovirus Type 5-Vectored Coronavirus Disease 2019 Vaccine Given as a Second Booster Dose in Guangzhou City, China.

Using a prospective, observational cohort study during the post-"dynamic COVID-zero" wave in China, we estimated short-term relative effectiveness against Omicron BA.5 infection of inhaled aerosolized adenovirus type 5-vectored ancestral strain coronavirus disease 2019 (COVID-19) vaccine as a second booster dose approximately 1 year after homologous boosted primary series of inactivated COVID-19 vaccine compared with no second booster. Participants reported nucleic acid or antigen test results weekly until they tested positive or completed predesignated follow-up. After excluding participants infected <14 days after study entry, relative effectiveness among the 6576 participants was 61% in 18- to 59-year-olds and 38% in ≥60-year-olds and was sustained for 12 weeks.

Real-World Effectiveness of Primary Series and Booster Doses of Inactivated Coronavirus Disease 2019 Vaccine Against Omicron BA.2 Variant Infection in China: A Retrospective Cohort Study.

BACKGROUND: China has been using inactivated coronavirus disease 2019 (COVID-19) vaccines as primary series and booster doses to protect the population from severe to fatal COVID-19. We evaluated primary and booster vaccine effectiveness (VE) against Omicron BA.2 infection outcomes. METHODS: This was a 13-province retrospective cohort study of quarantined close contacts of BA.2-infected individuals. Outcomes were BA.2 infection, COVID-19 pneumonia or worse, and severe/critical COVID-19. Absolute VE was estimated by comparison with an unvaccinated group. RESULTS: There were 289 427 close contacts ≥3 years old exposed to Omicron BA.2 cases; 31 831 turned nucleic acid amplification test-positive during quarantine, 97.2% with mild or asymptomatic infection, 2.6% with COVID-19 pneumonia, and 0.15% with severe/critical COVID-19. None died. Adjusted VE (aVE) against any infection was 17% for primary series and 22% when boosted. Primary series aVE in adults >18 years was 66% against COVID-19 pneumonia or worse and 91% against severe/critical COVID-19. Booster dose aVE was 74% against pneumonia or worse, and 93% against severe/critical COVID-19. CONCLUSIONS: Inactivated COVID-19 vaccines provided modest protection from infection, very good protection against pneumonia, and excellent protection against severe/critical COVID-19. Booster doses are necessary to provide strongest protection.

Changing Epidemiology of Hepatitis A in China: Evidence From Three National Serological Surveys and the National Notifiable Disease Reporting System.

BACKGROUND AND AIMS: China has conducted surveillance for hepatitis A since 1990, and hepatitis A was highly-to-intermediately endemic in 1992 when a Chinese hepatitis A vaccine (HepA) was licensed and introduced as a family-pay vaccine. In 2008, HepA was introduced into the Expanded Program on Immunization as a free childhood vaccine. APPROACH AND RESULTS: Three nationally representative surveys conducted in 1992, 2006, and 2014 assessed hepatitis B serology. The 1992 survey included hepatitis A virus (HAV) serology, and we tested sera from the 2006 and 2014 surveys for HAV antibodies. We used surveillance, seroprevalence, and vaccination status data to describe the changing epidemiology of hepatitis A in China from 1990 through 2014. Before HepA licensure, anti-HAV seroprevalence was 60% at 4 years of age, 70% at 10 years, and 90% at 59 years; incidence was 52/100,000 and peaked at 4 years. In 2006, after >10 years of private sector vaccination, HepA coverage was <30% among children <5 years, and incidence was 5.4/100,000 with a peak at 10 years. In 2014, coverage was >90% among children under 5 years; incidence was 1.9/100,000. Individuals born before the national introduction of HepA (1988-2004) had lower anti-HAV seroprevalence than earlier and later birth cohorts. CONCLUSIONS: The incidence of hepatitis A declined markedly following HepA introduction and improvement of sanitation and hygiene. The emerging epidemiology is consistent with disease-induced immunity having been replaced by vaccine-induced immunity, resulting in a low incidence of hepatitis A. Catch-up HepA campaigns to close the immunity gap among the 1998-2004 birth cohorts should be considered.

Detection of a Highly Divergent Type 3 Vaccine-Derived Poliovirus in a Child with a Severe Primary Immunodeficiency Disorder - Chongqing, China, 2022.

Oral poliovirus vaccine (OPV) has proven to be highly effective in the global effort to eradicate poliomyelitis because of its ability to induce both humoral and intestinal immunity, ease of administration, and low cost (1). Sabin-strain OPV contains live attenuated virus and induces immunity by replicating in the intestinal tract, triggering an immune response that clears the vaccine virus. However, among undervaccinated communities and persons with immunodeficiency, OPV mutations that arise during prolonged replication can result in the emergence of genetically divergent, neurovirulent vaccine-derived polioviruses (VDPVs). In addition, OPV has resulted in rare cases of vaccine-associated paralytic poliomyelitis (VAPP) among vaccine recipients or their close contacts (1). Identification of circulating polioviruses relies on surveillance of acute flaccid paralysis (AFP) and environmental surveillance of wastewater (i.e., sewage). In 2022, type 3 VDPV (VDPV3) was detected in stool specimens from an infant with primary immunodeficiency disorder (PID) through a pilot surveillance program to identify VDPVs in children with PIDs. Integrated AFP, environmental, and immunodeficiency-associated VDPV (iVDPV) surveillance is critical to detecting and containing all polioviruses and achieving the goal of global polio eradication.

Investment Case for a Comprehensive Package of Interventions Against Hepatitis B in China: Applied Modeling to Help National Strategy Planning.

BACKGROUND: In 2016, the first global viral hepatitis elimination targets were endorsed. An estimated one-third of the world's population of individuals with chronic hepatitis B virus (HBV) infection live in China and liver cancer is the sixth leading cause of mortality, but coverage of first-line antiviral treatment was low. In 2015, China was one of the first countries to initiate a consultative process for a renewed approach to viral hepatitis. We present the investment case for the scale-up of a comprehensive package of HBV interventions. METHODS: A dynamic simulation model of HBV was developed and used to simulate the Chinese HBV epidemic. We evaluated the impact, costs, and return on investment of a comprehensive package of prevention and treatment interventions from a societal perspective, incorporating costs of management of end-stage liver disease and lost productivity costs. RESULTS: Despite the successes of historical vaccination scale-up since 1992, there will be a projected 60 million people still living with HBV in 2030 and 10 million HBV-related deaths, including 5.7 million HBV-related cancer deaths between 2015 and 2030. This could be reduced by 2.1 million by highly active case-finding and optimal antiviral treatment regimens. The package of interventions is likely to have a positive return on investment to society of US$1.57 per US dollar invested. CONCLUSIONS: Increases in HBV-related deaths for the next few decades pose a major public health threat in China. Active case-finding and access to optimal antiviral treatment are required to mitigate this risk. This investment case approach provides a real-world example of how applied modeling can support national dialog and inform policy planning.

Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 to Close Contacts, China, January-February 2020.

We estimated the symptomatic, PCR-confirmed secondary attack rate (SAR) for 2,382 close contacts of 476 symptomatic persons with coronavirus disease in Yichang, Hubei Province, China, identified during January 23-February 25, 2020. The SAR among all close contacts was 6.5%; among close contacts who lived with an index case-patient, the SAR was 10.8%; among close-contact spouses of index case-patients, the SAR was 15.9%. The SAR varied by close contact age, from 3.0% for those <18 years of age to 12.5% for those >60 years of age. Multilevel logistic regression showed that factors significantly associated with increased SAR were living together, being a spouse, and being >60 years of age. Multilevel regression did not support SAR differing significantly by whether the most recent contact occurred before or after the index case-patient's onset of illness (p = 0.66). The relatively high SAR for coronavirus disease suggests relatively high virus transmissibility.

Progress in Vaccine-Preventable and Respiratory Infectious Diseases-First 10 Years of the CDC National Center for Immunization and Respiratory Diseases, 2006-2015.

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.

Transmission of measles among healthcare Workers in Hospital W, Xinjiang Autonomous Region, China, 2016.

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.

Advancing the National Immunization Program in an era of achieving universal vaccine coverage in China and beyond.

BACKGROUND: Immunization is a cornerstone of public health. Despite great success, China's National Immunization Program (NIP) faces challenges, such as the integration of several World Health Organization-recommended vaccines and other systemic issues. The Innovation Laboratory for Vaccine Delivery Research (VaxLab), supported by the Bill & Melinda Gates Foundation and established in 2021 at Duke Kunshan University, focuses on enhancing China's NIP through research and policy advocacy. This editorial aims to summarize the key findings of the manuscripts published in the collection contributed by VaxLab team and set the future research agenda. KEY FINDINGS: The collection contains eleven manuscripts discussing China's immunization landscape and strategies to improve coverage, particularly for non-NIP vaccines like human papillomavirus vaccine (HPV), pneumococcal conjugate vaccine (PCV), Haemophilus influenzae type b vaccine (Hib), and rotavirus vaccines. Key findings include: (i) The COVID-19 vaccination campaign demonstrated China's capacity for rapid, large-scale immunization efforts, suggesting potential for broader vaccine coverage improvements; (ii) Efforts in combating cervical cancer through the HPV vaccine indicate progress but also highlight challenges like vaccine supply and equitable access; (iii) The lag in adopting higher-valent paediatric combination vaccines in China needs attention to address regulatory and health system hurdles; (iv) Disparities in access to non-NIP vaccines underscore the need for government initiatives to improve vaccine coverage, especially for remote areas and marginalized populations; (v) Original studies emphasize the influence of caregivers' knowledge, health workers' financial incentives, and concerns about vaccine efficacy on immunization rates; (vi) Case studies from the Weifang City of China and Indonesia to introduce PCV offer insights on successful vaccine introduction strategies and the impact of innovative financing and government support. CONCLUSION: The articles emphasize the need for government leadership, strategic policymaking, and public awareness to enhance vaccine coverage and equity. The VaxLab will continue strengthening China's NIP by focusing on vaccine financing, emphasizing diversity, equity, and inclusion, and improving maternal vaccination coverage. Research will extend to Southeast Asian and Western Pacific regions, especially in middle-income countries facing challenges in vaccine financing and delivery. The collective efforts outlined in this collection show a commitment to evolving and adapting immunization strategies to meet global health goals and to provide equitable access to vaccines for all.

Thirty Years of Experience of Acute Flaccid Paralysis Surveillance for Polio - China, 1993-2022.

Introduction: Detecting poliovirus infections proves to be highly challenging due to their asymptomatic nature and infectious potential, highlighting the crucial importance of effective detection methods in the context of polio eradication efforts. In many countries, including China, the primary approach for identifying polio outbreaks has been through acute flaccid paralysis (AFP) surveillance. In this study, we conducted an evaluation spanning three decades (1993-2022) to assess the effectiveness of AFP surveillance in China. Methods: Data on all AFP cases identified since 1993 and national-level AFP surveillance system quality indicators aligned with the World Health Organization (WHO) standards were collected for analysis. The quality indicators assess surveillance sensitivity, completeness, timeliness of detection notification, case investigation, and laboratory workup. Surveillance sensitivity is determined by the non-polio AFP (NPAFP) detection rate among children under 15 years of age. Results: Between 1993 and 2022, a total of 150,779 AFP cases were identified and reported. Within this pool, surveillance identified 95 cases of wild poliovirus (WPV) and 24 cases due to vaccine-derived poliovirus. From 1995 onwards, the detection rate of NPAFP cases consistently adhered to the WHO and national standards of ≥1 case per 100,000, falling between 1.38 and 2.76. Starting in 1997, all timeliness indicators consistently achieved the criteria of 80%, apart from the consistency in meeting standards set for the rate of positive specimens sent to the national laboratory. Conclusions: AFP surveillance has been instrumental in China's accomplishment of maintaining a polio-free status. The ongoing adherence to key performance indicators, ensuring sensitivity and prompt specimen collection, demonstrates that AFP surveillance is proficient in detecting poliovirus in China. As we move into the post-eradication phase, AFP surveillance remains crucial for the sustained absence of polioviruses in the long term.

Accelerating into Immunization Agenda 2030 with momentum from China's successful COVID-19 vaccination campaign during dynamic COVID Zero.

China's immunization programs conducted a unified, tightly coordinated COVID-19 vaccination campaign during the dynamic COVID Zero period that reached well over 90% of the population with vaccines having > 90% effectiveness against serious-to-fatal COVID-19. The campaign was eight times the size of the annual routine national immunization program, administering 3.4 billion doses of vaccines while monitoring vaccine coverage, acceptability, safety, and effectiveness. Every asset of the routine immunization program had to be strengthened and expanded to attain high coverage and reach hundreds of millions of adults who had not been vaccinated since childhood. Program strengthening and expansion were in directions aligned with the World Health Organization's Immunization Agenda 2030, which has a vision that "everyone, everywhere, at every age fully benefits from vaccines for good health and well-being" and requires reaching all children, adolescents, and adults with lifesaving vaccines. Momentum from this campaign should not be lost but should be invested into achieving what is possible with a properly resourced national immunization program that is now proven to be capable of reaching everyone in the world's largest country throughout the life course, and to do so with all vaccines recommended by the World Health Organization.

Effectiveness of DTaP Against Pertussis in ≤2-Year-Old Children - Linyi Prefecture, Shandong Province, China, 2017-2019.

What is already known about this topic?: Vaccine effectiveness (VE) is positively correlated with the number of administered co-purified diphtheria, tetanus, and acellular pertussis vaccine (DTaP) doses. A matched case-control study conducted in Zhongshan City revealed that the co-purified DTaP VE against pertussis-related illnesses in children aged 4-11 months was 42% for one dose, 88% for two doses, and 95% for three doses, respectively. What is added by this report?: The results of this study contribute to the current body of research. We found that the VE of co-purified DTaP against pertussis-related illness and hospitalization increased substantially, ranging from 24%-26% after one dose to 86%-87% after four doses. What are the implications for public health practice?: The results of this study underscore the significance of prompt and comprehensive immunization using co-purified DTaP to decrease the incidence of pertussis. Additionally, these findings offer evidence supporting the modification of China's pertussis vaccination approach.

Analysis of a Sabin-Strain Inactivated Poliovirus Vaccine Response to a Circulating Type 2 Vaccine-Derived Poliovirus Event in Sichuan Province, China 2019-2021.

Importance: The Sabin-strain inactivated poliovirus vaccine (IPV) may be a tool for polio outbreak response in certain situations. Objective: To investigate the response to a type 2 vaccine-derived poliovirus (VDPV2) outbreak. Design, Setting, and Participants: This case series was conducted in China after a VDPV2 was detected in stool specimens from a child with acute flaccid paralysis (AFP) in Sichuan Province in 2019, 3 years after the global withdrawal of live, attenuated type 2 oral poliovirus vaccine (OPV). Investigation followed National Health Commission and World Health Organization guidance and included searching hospitals for unreported AFP cases; testing stool specimens from the child, his contacts, and local children; enhanced environmental surveillance for VDPV2s in wastewater; and measuring vaccination coverage. Sabin-strain IPV campaigns were conducted in a wide geographic area. Main Outcomes and Measures: Any VDPV2 detection after completion of the supplementary immunization activities. Results: A 28-nucleotide-change VDPV2 was isolated from a young boy. Three VDPV2s were detected in healthy children; 2 were contacts of the original child, and none had paralysis. A search of 31 million hospital records found 10 unreported AFP cases; none were polio. No type 2 polioviruses were found in wastewater. Prior to the event, polio vaccine coverage was 65% among children younger than 5 years. Sabin-strain IPV campaigns reached more than 97% of targeted children, administering 1.4 million doses. No transmission source was identified. More than 1 year of enhanced poliovirus environmental and AFP surveillance detected no additional VDPVs. Conclusions and Relevance: These findings suggest that the circulating VPDV2 outbreak in 2019 was associated with low vaccine coverage. An investigation discovered 3 infected but otherwise healthy children and no evidence of the virus in wastewater. Following Sabin-strain IPV-only campaigns expanding from county to prefecture, the poliovirus was not detected, and the outbreak response was considered by an expert panel and the World Health Organization to have been successful. This success suggests that the Sabin-strain IPV may be a useful tool for responding to circulating VDPV2 outbreaks when high-quality supplementary immunization activities can be conducted and carefully monitored in settings with good sanitation.

Safety, immunogenicity, and immune persistence of two inactivated COVID-19 vaccines replacement vaccination in China: An observational cohort study.

BACKGROUND: To mitigate a national shortage of WIBP-CorV COVID-19 vaccine, China's regulator approved administering BBIBP-CorV after WIBP-CorV for completion of a primary series. In a pragmatic observational study, we compared immunogenicity and safety of a primary series of WIBP-CorV followed by BBIBP-CorV with a primary series of two doses of BBIBP-CorV. METHODS: We invited healthy 18-59-years-old adults who had already received either WIBP-CorV or BBIBP-CorV as their first dose in a primary series to participate in this observational cohort study. Subjects who had received WIBP-CorV as their first dose became the observation group; subjects who had received BBIBP-CorV as their first dose became the control group. All participants received BBIBP-CorV as their second dose. We obtained sera 1, 2, and 6 months after second doses for nAb titer measurement by micro-neutralization cytopathic effect assay with SARS-CoV-2 strain HB01, standardized with WHO International Standard for anti-SARS-CoV-2 immunoglobulin. Safety was assessed for the 7 days after administration of second doses. RESULTS: Between March and December 2021, 275 subjects were included in the observation group and 133 in the control group. Neutralizing seropositivity (≥1:4) rates were 98.91 % and 99.25 % at 1 month and 53.16 % and 70.69 % at 6 months. One-month geometric mean titers (GMTs) were 21.33 and 22.45; one-month geometric mean concentrations (GMCs) were 227.71 IU/mL and 273.27 IU/mL. One to two months after vaccination, observation group seropositivity rates and titers were not significantly different to the control group's. Adverse reaction rates were 11.27 % and 18.80 %, all mild or moderate in severity. CONCLUSIONS: Both primary series were immunogenic; immunogenicity of WIBP-CorV followed by BBIBP-CorV was not different than immunogenicity following two doses of BBIBP-CorV for two months after vaccination; safety profiles were acceptable for both regimens. BBIBP-CorV can be used to complete a primary series that started with WIBP-CorV.

Factors associated with neutralizing antibody levels induced by two inactivated COVID-19 vaccines for 12 months after primary series vaccination.

Background: BBIBP-CorV and CoronaVac inactivated COVID-19 vaccines are widely-used, World Health Organization-emergency-listed vaccines. Understanding antibody level changes over time after vaccination is important for booster dose policies. We evaluated neutralizing antibody (nAb) titers and associated factors for the first 12 months after primary-series vaccination with BBIBP-CorV and CoronaVac. Methods: Our study consisted of a set of cross-sectional sero-surveys in Zhejiang and Shanxi provinces, China. In 2021, we enrolled 1,527 consenting 18-59-year-olds who received two doses of BBIBP-CorV or CoronaVac 1, 3, 6, 9, or 12 months earlier and obtained blood samples and demographic and medical data. We obtained 6-month convalescent sera from 62 individuals in Hebei province. Serum nAb titers were measured by standard micro-neutralization cytopathic effect assay in Vero cells with ancestral SARS-CoV-2 strain HB01. We used the first WHO International Standard (IS) for anti-SARS-CoV-2 immunoglobulin (NIBSC code 20/136) to standardized geometric mean concentrations (IU/mL) derived from the nAb geometric mean titers (GMT over 1:4 was considered seropositive). We analyzed nAb titer trends using Chi-square and factors related to nAb titers with logistic regression and linear models. Results: Numbers of subjects in each of the five month-groupings ranged from 100 to 200 for each vaccine and met group-specific target sample sizes. Seropositivity rates from BBIBP-CorV were 98.0% at 1 month and 53.5% at 12 months, and GMTs were 25.0 and 4.0. Respective seropositivity rates from CoronaVac were 90.0% and 62.5%, and GMTs were 20.2 and 4.1. One-, three-, six-, nine-, and twelve-month GMCs were 217.2, 84.1, 85.7, 44.6, and 10.9 IU/mL in BBIBP-CorV recipients and 195.7, 94.6, 51.7, 27.6, and 13.4 IU/mL in CoronaVac recipients. Six-month convalescent seropositivity was 95.2%; GMC was 108.9 IU/mL. Seropositivity and GMCs were associated with age, sex, and time since vaccination. Conclusions: Neutralizing Ab levels against ancestral SARS-CoV-2 from BBIBP-CorV or CoronaVac vaccination were similar and decreased with increasing time since vaccination; over half of 12-month post-vaccination subjects were seropositive. Seropositivity and GMCs from BBIBP-CorV and CoronaVac six and nine months after vaccination were similar to or slightly lower than in six-month convalescent sera. These real-world data suggest necessity of six-month booster doses.

Vaccination coverage among U.S. adolescents aged 13-17 years eligible for the Vaccines for Children program, 2009.

OBJECTIVES: We compared (1) characteristics of adolescents who are and are not entitled to receive free vaccines from the Vaccines for Children (VFC) program and (2) vaccination coverage with meningococcal conjugate (MCV4), quadrivalent human papillomavirus (HPV4), and tetanus-diphtheria-acellular pertussis (Tdap) vaccines among VFC-eligible and non-VFC-eligible adolescents. METHODS: We analyzed data from the 2009 National Immunization Survey-Teen, a nationally representative, random-digit-dialed survey of households with adolescents aged 13-17 years (n = 20,066). Differences in sociodemographic characteristics and provider-reported vaccination coverage were evaluated using t-tests. RESULTS: Overall, 32.1% (+/- 1.2%) of adolescents were VFC-eligible. VFC-eligible adolescents were significantly less likely than non-VFC-eligible adolescents to be white and to live in suburban areas, and more likely to live in poverty and to have younger and less educated mothers. Nationally, coverage among non-VFC-eligible adolescents was 57.1% (+/-1.5%) for > or = 1 dose of Tdap, 55.4% (+/-1.5%) for > or = 1 dose of MCV4, and 43.2% (+/- 2.2%) for > or = 1 dose of HPV4. Coverage among VFC-eligible adolescents was 52.5% (+/- 2.4%) for > or = 1 dose of Tdap, 50.1% (+/- 2.4%) for > or = 1 dose of MCV4, and 46.6% (+/- 3.5%) for > or =1 dose of HPV4. Only 27.5% (+/- 1.8%) of non-VFC-eligible adolescents and 25.0% (+/- 2.9%) of VFC-eligible adolescents received > or = 3 doses of HPV4. Vaccination coverage was significantly higher among non-VFC-eligible adolescents for Tdap and MCV4, but not for one-dose or three-dose HPV4. Conclusions. Coverage with some recommended vaccines is lower among VFC-eligible adolescents compared with non-VFC-eligible adolescents. Continued monitoring of adolescent vaccination rates, particularly among VFC-eligible populations, is needed to ensure that all adolescents receive all routinely recommended vaccines.

Vaccination coverage among U.S. children aged 19-35 months entitled by the Vaccines for Children program, 2009.

OBJECTIVES: Following the measles outbreaks of the late 1980s and early 1990s, vaccination coverage was found to be low nationally, and there were pockets of underimmunized children primarily in inner cities. We described the percentage and demographics of children who were entitled to the Vaccines for Children (VFC) program in 2009 and evaluated whether Healthy People 2010 (HP 2010) vaccination coverage objectives of 90% were achieved among these children. METHODS: We analyzed data from 16,967 children aged 19-35 months sampled by the National Immunization Survey in 2009. VFC-entitled children included children who were (1) on Medicaid, (2) not covered by health insurance, (3) of American Indian/Alaska Native race/ethnicity, or (4) covered by private health insurance that did not pay all of the costs of vaccines, but who were vaccinated at a Federally Qualified Health Center or a Rural Health Center. RESULTS: An estimated 49.7% of all children aged 19-35 months were entitled to VFC vaccines. Compared with children who did not qualify for VFC, the VFC-entitled children were significantly more likely to be Hispanic or non-Hispanic black; to have a mother who was widowed, divorced, separated, or never married; and to live in a household with an annual income below the federal poverty level. Mothers of VFC-entitled children were significantly less likely to have some college experience or to be college graduates. Of nine vaccines analyzed, two vaccines--polio at 91.7% and hepatitis B at 92.2%--achieved the HP 2010 90% coverage objective for VFC-entitled children, and four others, including measles-mumps-rubella at 88.8%, achieved greater than 80% coverage. Conclusions. Today, children with demographic characteristics like those of children who were at the epicenter of the measles outbreaks two decades ago are entitled to VFC vaccines at no cost, and have achieved high vaccination coverage levels.

Assessing the burden of congenital rubella syndrome in China and evaluating mitigation strategies: a metapopulation modelling study.

BACKGROUND: A rubella vaccine was licensed in China in 1993 and added to the Expanded Programme on Immunization in 2008, but a national cross-sectional serological survey during 2014 indicates that many adolescents remain susceptible. Maternal infections during the first trimester often cause miscarriages, stillbirths, and, among livebirths, congenital rubella syndrome. We aimed to evaluate possible supplemental immunisation activities (SIAs) to accelerate elimination of rubella and congenital rubella syndrome. METHODS: We analysed residual samples from the national serological survey done in 2014, data from monthly rubella surveillance reports from 2005 and 2016, and additional publications through a systematic review. Using an age-structured population model with provincial strata, we calculated the reproduction numbers and evaluated the gradient of the metapopulation effective reproduction number with respect to potential supplemental immunisation rates. We corroborated these analytical results and estimated times-to-elimination by simulating SIAs among adolescents (ages 10-19 years) and young adults (ages 20-29 years) using a model with regional strata. We estimated the incidence of rubella and burden of congenital rubella syndrome by simulating transmission in a relatively small population lacking only spatial structure. FINDINGS: By 2014, childhood immunisation had reduced rubella's reproduction number from 7·6 to 1·2 and SIAs among adolescents were the optimal elimination strategy. We found that less than 10% of rubella infections were reported; that although some women with symptomatic first-trimester infections might have elected to terminate their pregnancies, 700 children could have been born with congenital rubella syndrome during 2014; and that timely SIAs would avert outbreaks that, as susceptible adolescents reached reproductive age, could greatly increase the burden of this syndrome. INTERPRETATION: Our findings suggest that SIAs among adolescents would most effectively reduce congenital rubella syndrome as well as eliminate rubella, owing both to fewer infections in the immunised population and absence of infections that those immunised would otherwise have caused. Metapopulation models with realistic mixing are uniquely capable of assessing such indirect effects. FUNDING: WHO and National Science Foundation.

Long-term seropositivity, safety, and impact of inactivated and live, attenuated hepatitis a vaccines in China - A cross-sectional study.

BACKGROUND: In 2008, China introduced live, attenuated hepatitis A vaccine (L-HepA, licensed in 1992) and inactivated hepatitis A vaccine (I-HepA, licensed in 2002) nationwide, and is currently the only country using L-HepA in routine immunization. We assessed seropositivity and its duration following vaccination, safety, and association with hepatitis A incidence and population seroprevalence for I-HepA and L-HepA. METHODS: We obtained seroprevalence data from two nationwide serosurveys (in 1992 and 2014), vaccination status from the 2014 serosurvey, and vaccine safety and disease incidence data from the national surveillance system. We compared long-term HAV seropositivity among vaccine recipients and described safety profiles of both vaccines. We categorized the 31 provinces into those predominately using I-HepA and achieving high coverage (n = 4), those predominately using L-HepA achieving high coverage (n = 4), and those predominately using L-HepA achieving lower coverage (n = 23). We compared population HAV seropositivity, coverage, and disease incidence among the three groups. RESULTS: One year after vaccination, seropositivity from I-HepA was significantly higher than from L-HepA (97.8% vs 90.7%), and seropositivity declined to 73.5% for L-HepA and 75.4% for I-HepA after 10 years - not significantly different by vaccine. The annual incidence of serious AEFI was <0.5/100 000 for both vaccines. Prior to licensure of either HepA vaccine, provinces that would go on to predominantly use I-HepA had lower incidences of hepatitis A and lower seropositivity levels to HAV than provinces that would go on to use L-HepA. By 2014, these differences were significantly diminished. Regardless of vaccine selection, all three province groups had lower immunity to HAV among individuals born during the 10 years prior to nationwide vaccine introduction - individuals who were 10 to 24 years old in 2014. CONCLUSION: Evidence of good immunogenicity, safety, and impact on incidence supports continued use of both I-HepA and L-HepA in the EPI system. These results may be useful for countries considering integrating HepA vaccines into their routine programs.

Review of the status and challenges associated with increasing influenza vaccination coverage among pregnant women in China.

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.