Estimate Vaccination Coverage Research Articles

Influenza vaccination coverage among persons seeking outpatient medical care for acute respiratory illness in five states in the United States, 2011–2012 through 2018–2019

BackgroundIn the United States (U.S.), annual influenza vaccination has been recommended for all persons aged ≥6 months with the Healthy People 2020 coverage target of 70%. However, vaccination coverage has remained around 42–49% during the past eight influenza seasons. We sought to quantify influenza vaccination coverage and factors associated with vaccination in persons seeking outpatient medical care for an acute respiratory illness (ARI). MethodsWe enrolled outpatients aged ≥6 months with ARI from >50 U.S. clinics from 2011 to 2012 through 2018–2019 influenza seasons and tested for influenza with molecular assays. Vaccination status was based on documented receipt of the current season’s influenza vaccine. We estimated vaccination coverage among influenza-negative study participants by study site, age, and season, and compared to state-level influenza coverage estimates in the general population based on annual immunization surveys. We used multivariable logistic regression to examine factors independently associated with receipt of influenza vaccines. ResultsWe enrolled 45,424 study participants with ARI who tested negative for influenza during the study period. Annual vaccination coverage among influenza-negative ARI patients and the general population in the participating states averaged 55% (range: 47–62%), and 52% (range: 46–54%), respectively. Among enrollees, coverage was highest among adults aged ≥65 years (82%; range, 80–85%) and lowest among adolescents aged 13–17 years (38%; range, 35–41%). Factors significantly associated with non-vaccination included non-White race, no college degree, exposure to cigarette smoke, absence of high-risk conditions, and not receiving prior season influenza vaccine. ConclusionsInfluenza vaccination coverage over eight seasons among outpatients with non-influenza respiratory illness was slightly higher than coverage in the general population but 15% lower than national targets. Increased efforts to promote vaccination especially in groups with lower coverage are warranted to attain optimal health benefits of influenza vaccine.

Using the health belief model to identify barriers to seasonal influenza vaccination among Australian adults in 2019.

BackgroundEach year tens of thousands of Australians become ill with influenza, resulting in thousands of severe infections that require hospitalisation. However, only 40% of adults receive the annual influenza vaccine. We surveyed Australian adults to provide up to date, population‐specific data on the predictors and barriers of seasonal influenza vaccination.MethodsWe administered an online survey to a nationally representative sample of Australian adults. We designed survey questions using the theoretical constructs of the health belief model. Using simple and multivariable Poisson regression, we identified attitudes and beliefs associated with influenza vaccination in 2019.ResultsAmong 1,444 respondents, 51.7% self‐reported influenza vaccination in 2019. We estimated vaccine coverage to be 44% for adults under 45, 46% for adults aged 45 to 64 and 77% for adults aged 65 and over. The strongest individual predictors of self‐reported vaccination were believing the vaccine is effective at preventing influenza (APR = 3.71; 95% CI = 2.87‐4.80), followed by recalling their doctor recommending the vaccine (APR = 2.70; 95% CI = 2.31‐3.16). Common perceived barriers that predicted self‐reported vaccination included believing the vaccine could give you influenza (APR = 0.59; 95% CI = 0.52‐0.67), believing the vaccine can make you ill afterwards (APR = 0.68; 95% CI = 0.62‐0.74) and preferring to develop immunity “naturally” (APR = 0.38; 95% CI = 0.32‐0.45).ConclusionAlthough vaccine uptake in 2019 appears to be higher than previous years, there are perceived barriers which may limit uptake among Australians. Tailored interventions are needed to combat widespread influenza vaccine hesitancy, particularly among high‐risk groups.

Loss of protective immunity of two-dose mumps-containing vaccine over time: concerns with the new strategy of the mumps immunization program in China

ABSTRACT Background: Currently, children aged 6–9 years have the highest incidence rate of mumps in China. Although China has introduced a two-dose schedule of measles-mumps-rubella vaccine into routine immunization (at 8 months and 18 months), the incidence rate of mumps in high-risk populations might not decrease due to waning immunity. Here we report a mumps outbreak supporting this hypothesis. Methods: The descriptive epidemiological method was used to summarize the overall characteristics of the course of the outbreak. We conducted a retrospective cohort study to evaluate the vaccine effectiveness (VE) of mumps-containing vaccine (MuCV). Results: A total of 78 cases were identified during the outbreak and the estimated vaccination coverage was 84.7%. Of 454 vaccinated students, 335 (73.8%) had received one-dose MuCV, 93 (20.5%) two-dose, and 26 (5.7%) three-dose. The VEs for both the one-dose (−17.0%, 95%CI: −120.3–38.2%) and two-dose groups (−10.0%, 95%CI: −138.0–48.8%) were not performed well, whereas the VE for the three-dose group was 100%. However, we found that the overall VE was 74.2% (95% CI: 9.7–92.6%) for students vaccinated within 5 years. We also observed that there was a broadly linear increase in mumps infection risk in both one-dose and two-dose group when the time since last dose vaccination was more than 5 years. Conclusions: The overall VE for both one-dose and two-dose MuCV was discouraging, but it appeared to be moderately effective within 5 years after vaccination. Further surveillance and seroepidemiological data are needed to understand the impact of the new vaccination strategy on mumps in China.

District-level estimation of vaccination coverage: Discrete vs continuous spatial models.

Health and development indicators (HDIs) such as vaccination coverage are regularly measured in many low‐ and middle‐income countries using household surveys, often due to the unreliability or incompleteness of routine data collection systems. Recently, the development of model‐based approaches for producing subnational estimates of HDIs using survey data, particularly cluster‐level data, has been an active area of research. This is mostly driven by the increasing demand for estimates at certain administrative levels, for example, districts, at which many development goals are set and evaluated. In this study, we explore spatial modeling approaches for producing district‐level estimates of vaccination coverage. Specifically, we compare discrete spatial smoothing models which directly model district‐level data with continuous Gaussian process (GP) models that utilize geolocated cluster‐level data. We adopt a fully Bayesian framework, implemented using the INLA and SPDE approaches. We compare the predictive performance of the models by analyzing vaccination coverage using data from two Demographic and Health Surveys (DHS), namely the 2014 Kenya DHS and the 2015‐16 Malawi DHS. We find that the continuous GP models performed well, offering a credible alternative to traditional discrete spatial smoothing models. Our analysis also revealed that accounting for between‐cluster variation in the continuous GP models did not have any real effect on the district‐level estimates. Our results provide guidance to practitioners on the reliability of these model‐based approaches for producing estimates of vaccination coverage and other HDIs.

Association of vaccine awareness and confidence on the influenza vaccination status of Al Ahsa, Saudi Arabia residents

ABSTRACT While the Saudi Arabian Ministry of Health has made seasonal influenza vaccination available for several years, there remains a scarcity of vaccination coverage reports outside of the capital city. Understanding factors that affect vaccine uptake is important in developing strategies to improve coverage. This analytic cross-sectional study utilized data from 1377 adult residents randomly selected through a multi-stage sampling procedure from the three administrative sectors of Al Ahsa, Saudi Arabia. Estimates of influenza vaccine coverage were determined for various demographic groups. Logistic regression was applied to determine the associations among the respondents’ awareness on influenza vaccination services, their confidence on the influenza vaccine efficacy and safety and their vaccination status. The estimated influenza vaccination coverage was 44.15% (95% CI = 41.55; 46.79). The proportion of residents who received the influenza vaccine differed between demographic groups. Al Ahsa residents who were aware that influenza vaccine is available and those who were aware that it is available for free were 2.7 and 6.3 times more likely to be immunized (p < .001) compared to those who were unaware. Residents who were confident that it is effective in preventing influenza and its complications were 3.6 times more like to be vaccinated while those who were confident that the vaccine is safe were 4.5 times more likely to be immunized (p < .001). Seasonal influenza coverage in Al Ahsa remains low despite the availability of free immunization in the government health facilities. Awareness about vaccine availability and confidence in vaccine efficacy and safety were important determinants of vaccination status.

Pairs of independent nationally representative vaccination coverage surveys conducted within one year of each other: A global overview covering 2000–2019

BackgroundPopulation-based surveys play an important role in measuring vaccination coverage. Surveys measuring vaccination coverage may be commissioned by the Expanded Programme on Immunization (EPI surveys) or part of multi-domain non-EPI surveys such as Demographic and Health Surveys (DHS) or Multiple Indicator Cluster Surveys (MICS). Surveys conducted too close in time to each other may not only be an inefficient use of resources but may also create problems for programme staff when results suggest inconsistent patterns of programme performance for similar time periods. ObjectiveTo summarize the occurrence of vaccination coverage surveys conducted close in time during 2000–2019 and compare results of EPI and non-EPI coverage surveys when the surveys were conducted within one year of each other. MethodsUsing a database of published national-level vaccination coverage survey results compiled by the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF), the authors abstracted information on survey field work dates, sample size, percentage of children with documented history of vaccination and the percent coverage, as well as published uncertainty intervals from DHS and MICS, for the first and third doses of diphtheria-tetanus toxoid-pertussis containing vaccine (DTP1, DTP3) and first dose of measles containing vaccine (MCV1). Survey results of EPI and non-EPI surveys were compared. ResultsThe authors identified 646 surveys with final reports and estimates of national-level vaccination coverage for DTP1, DTP3, or MCV1 from a total of 687 surveys with data collection start date from 2000 to 2019. Of the 140 countries with at least one vaccination coverage survey, a median of four surveys was observed. Most countries were Gavi-eligible and located in the WHO Africa Region. Sixty-six survey dyads were identified where an EPI survey occurred within one year of a non-EPI survey. For the 66 dyads, in 49 of 59 with information available, EPI surveys reported higher proportion of documented evidence of vaccination and EPI survey results tended to suggest higher levels of vaccination coverage compared to the non-EPI surveys; quite often, differences were substantial. Surveys that found higher proportions of children with documented vaccination evidence tended to also find higher proportions of children who had been vaccinated. SummaryOpportunities exist to improve overall planning of vaccination coverage measurement in population-based household surveys so that both EPI and non-EPI surveys are more comparable and survey coverage estimates are more appropriately spaced in time. When surveys occur too close in time, careful attention is warranted to ensure comparability and assess sources of documented evidence of vaccination and related coverage differences.

Determinants and coverage of seasonal influenza vaccination among women of childbearing age in Poland.

Vaccination is the most effective method of controlling influenza in the human population, where pregnant women belong to a risk group that is especially vulnerable to influenza-related morbidity and mortality. The objectives of the survey were to report estimates of maternal vaccination coverage and assess reasons for the lack of influenza vaccination among Polish women of childbearing age. The survey analysis included 564 pregnant women who had been surveyed in a self-reported questionnaire during the 2017-2018 influenza season in Warsaw, Poland. Over 95% of Polish women of childbearing age did not vaccinate against influenza due to the low perception of risk and a lack of providing evidence-based information on vaccine by physicians and midwives. General practitioners were most often indicated as healthcare workers who educated women about influenza risk factors and recommended influenza vaccine to them. The results of the survey suggest that women of childbearing age did not vaccinate against influenza due to the low perception of risk and a lack of providing evidence-based information by healthcare workers (including obstetrician-gynaecologists and midwives), while their recommendations appear to be a powerful method of overcoming barriers to influenza vaccination among patients.

Measles outbreak among children ≤15 years old, Jaintia Hills District, Meghalaya, India, 2017.

Of 1115 measles outbreaks during 2015 in India, 61,255 suspected measles cases were reported. In 2016, a measles outbreak was reported at East and West Jaintia Hills districts in Meghalaya State, India. The outbreak was investigated to describe the epidemiology, estimate vaccination coverage and vaccine effectiveness (VE), determine risk factors for the disease, and recommend control and prevention measures. A measles case was defined as new-onset fever with maculopapular rash occurring between May 1, 2016, and January 21, 2017, in a resident of East and West Jaintia Hills. Cases were identified by active and passive surveillance. Serum and urine samples were collected from cases with laboratory diagnosis for confirmation. A retrospective cohort study was conducted to estimate vaccination coverage, VE, and risk factors for the disease. We identified 382 cases (51% female). The attack rate was 24% with three deaths. The case fatality rate was <1%. The median age was 4 years (range: 3 months-12 years). Among children 12-60 months, 128 (56%) received measles-containing-vaccine first-dose (MCV1), 85 (37%) received measles-containing-vaccine second-dose (MCV2), and 80 (35%) received Vitamin A. VE for MCV1 was 78% and for MCV2 94%. Being unvaccinated for MCV1 (relative risk [RR] = 9.7, 95% confidence interval [CI] = 4.6-20.5) and MCV2 (RR = 17.4, 95% CI = 4.3-69.4) were both strongly associated with illness. Poor vaccination coverage led to the measles outbreak in East and West Jaintia Hills districts of Meghalaya. Strengthening the routine immunization systems and improving Vitamin A uptake is essential to prevent further outbreaks.

Vaccination timeliness and completeness among preterm and low birthweight infants: a national cohort study

ABSTRACT Vaccinating premature and low birthweight (LBW) infants according to chronological age has been found safe and effective. Although these infants are susceptible to infections, vaccinations are often delayed. We estimated vaccination coverage (VC) in preterm and LBW infants compared to term infants in a cohort study (2016 Israel birth cohort, n = 181,543) using the National Immunization Registry. Vaccinations included Hepatitis B, Diphtheria-Tetanus-acellular Pertussis-IPV-Haemophilus influenzae B, Oral Polio Bivalent, Rotavirus, Pneumococcal Conjugate, Measles-Mumps-Rubella-Varicella and Hepatitis A. Inclusion criteria: (1) born in Israel; (2) having a unique identifier (allowing data matching); and (3) surviving to 24 months. VC at 24 months and timeliness of vaccine doses were evaluated according to infants’ birthweight (BW) and gestational age (GA). Preterm infants (GA < 37 weeks) comprised 7.0% (n = 12,264); LBW infants (BW< 2500 g) were 7.7% (n = 13,950); BW was 1500–2499 g in 6.8%, 1000–1499 g in 0.6% and below 1000 g in 0.3%. Compared to normal birthweight (NBW) infants (BW≥2500 g), LBW infants showed delayed initiation of vaccinations. Odds ratio (OR) for delay: DTaP-IPV-Hib 1 OR = 1.26 [95%CI 1.19–1.33]; Rota 1, OR = 1.22 [95%CI 1.16–1.29]. Vaccination delay rates were higher among smaller new-borns (below 1000 g). At 24 months there was no significant difference regarding vaccination status. This national cohort VC analysis focused on preterm/LBW infants. Vaccinating preterm and LBW infants according to the recommended schedule induces protection against life-threatening infectious diseases. Vaccination initiation among LBW infants showed considerable delay. Health practitioners and parents should cooperate to improve timely vaccination initiation.

Mapping routine measles vaccination in low- and middle-income countries

The safe, highly effective measles vaccine has been recommended globally since 1974, yet in 2017 there were more than 17 million cases of measles and 83,400 deaths in children under 5 years old, and more than 99% of both occurred in low- and middle-income countries (LMICs)1–4. Globally comparable, annual, local estimates of routine first-dose measles-containing vaccine (MCV1) coverage are critical for understanding geographically precise immunity patterns, progress towards the targets of the Global Vaccine Action Plan (GVAP), and high-risk areas amid disruptions to vaccination programmes caused by coronavirus disease 2019 (COVID-19)5–8. Here we generated annual estimates of routine childhood MCV1 coverage at 5 × 5-km2 pixel and second administrative levels from 2000 to 2019 in 101 LMICs, quantified geographical inequality and assessed vaccination status by geographical remoteness. After widespread MCV1 gains from 2000 to 2010, coverage regressed in more than half of the districts between 2010 and 2019, leaving many LMICs far from the GVAP goal of 80% coverage in all districts by 2019. MCV1 coverage was lower in rural than in urban locations, although a larger proportion of unvaccinated children overall lived in urban locations; strategies to provide essential vaccination services should address both geographical contexts. These results provide a tool for decision-makers to strengthen routine MCV1 immunization programmes and provide equitable disease protection for all children.

Religion and measles vaccination in Indonesia, 2007–2017

Background: Some Muslim religious councils in Indonesia have ruled that the measles vaccine contains haram materials, and there is concern that vaccination coverage may decrease as a result. The aims of this study are to (1) evaluate changes in measles vaccination coverage between 2007 and 2017, and (2) compare vaccination coverage between Muslims and non-Muslims in Indonesia. Methods and materials: Three cross-sectional datasets of mothers of children 12–23 months old were used: The Demographic and Health Surveys from 2007, 2012, and 2017 in Indonesia. Participants were only asked about religion in 2007, and so 100 datasets of religion were imputed for 2012 and 2017, with the probability being Muslim calculated as the proportion of individuals who were Muslim in the participant's province as of 2007. In this multiple imputation analysis, Poisson regression models output prevalence differences (PD) and 95% confidence intervals (CI), adjusted for wealth index and age of the child in months. An interaction term between year and religion evaluated changes in vaccination over time by religion. Results: Across the three datasets, there were 10,524 children, of whom 78.9% were vaccinated against measles. Across 32 provinces, the unweighted prevalence of Islam in 2007 ranged from 8% in East Nusa Tenggara to 100% in South Sumatra, for a weighted average of 85.4%. In the main effects model, non-Muslims had 3.5% higher vaccination coverage (95% CI: 1.1%, 6.0%), and compared to 2007, vaccination coverage increased in 2012 (PD: 3.6%, 95% CI: 1.7%, 6.0%) and 2017 (PD: 4.6%, 95% CI: 2.6%, 6.5%). In the models with an interaction term between year and religion, the estimated vaccination coverage for children 12 months old in the highest wealth quintile was 79.3% (95% CI: 76.5%, 82.1%) in 2007 and 82.9% (80.1%, 85.8%) in 2017. In contrast, vaccination coverage increased more for non-Muslims from 81.4% (95% CI: 77.6%, 85.2%) in 2007 to 89.6% (85.0%, 94.3%) in 2017. Conclusion: Measles vaccination coverage has been increasing in non-Muslims, but not Muslims, in Indonesia. Because further proclamations about vaccine products were issued after 2017, future studies should continue to examine the relationship between religion and vaccine uptake in Indonesia.

Abstract PO-273: Human papillomavirus vaccination: California state-level mapping to identify gaps and inform practice and policy

Abstract Background: The human papillomavirus (HPV) virus is a known pathogen and carcinogen causing deadly cancers of the genitalia and head and neck. The HPV vaccine is a safe, effective cancer-preventing vaccine recommended for girls and boys at ages 11-12. Full HPV vaccine coverage is available through health insurance plans and the state of California, yet no data were readily available to describe California state-wide coverage of HPV vaccination. The Data Workgroup of the California HPV Vaccination Roundtable aimed to map State-level HPV vaccine coverage. Methods: Workgroup collected, analyzed, and mapped 2018 HPV vaccination data from the NIS-T survey, quality performance metrics from public and private health plans, and the statewide CAIR. NIS-T provides state-level estimates of routine adolescent vaccines, including HPV. Performance data were obtained from Medi-Cal and commercial health plans, administrative claims, and medical records. CAIR contains individual-level, provider-reported immunizations. HPV vaccination coverage for adolescents were estimated at the state and county level. Maps of county-level HPV vaccination and HPV-related cancer rates were built. Results: Rates of HPV-related cancers ranged from 6-12 per 100,000. Regarding HPV vaccination, there were considerable variation in the metrics and limitations of each data source, therefore estimates are not easily comparable. CAIR estimates of HPV vaccination coverage (28%) are lower than those for Medi-Cal managed care (45%) and commercial HMO members (50%). In 2018, aggregated results showed that overall 50% of 13 year old were vaccinated. We observed in the CAIR data that boys and girls are vaccinated at similar rates. However, significant county/regional HPV vaccination rates exist ranging from 9% (rural, northern) to 55% (urban, western). Northern, rural country have both the lowest HPV vaccination completion rates for 13-year-olds (9%), and the highest HPV-attributable cancer rates in the state (12 cases per 100,000 persons. Race/ethnic variations exist for HPV vaccination and HPV- related cancers–especially cervical cancer. Conclusions: This state-level data report approach may facilitate practice and policy action and help other states in developing their own reports for HPV vaccine improvements. Stakeholders are encouraged to utilize this Report when planning HPV vaccination interventions. We recommend that health systems: 1) assess HPV vaccination rates for 13-year-olds, 2) establish data exchange with CAIR, 3) implement recommended strategies to improve coverage, 4) collaborate with health plans and clinicians and 5) partner with community advocacy groups and clinic/hospital parent/patient advisory groups to improve data accuracy, as well as reduce HPV vaccine hesitance and promote at least 80% HPV vaccination completion by 2026. Citation Format: Jaime Adler, Raquel Arias, Kimlin Tam Ashing, Shauntay Davis-Patterson, Hilary Gillette-Walch, Jeffrey Klausner, Jim Knox, Beverly Mitchell, Autumn Ogden-Smith, Jane Pezua, Rita Singhal, Hoa Su. Human papillomavirus vaccination: California state-level mapping to identify gaps and inform practice and policy [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-273.

Implications of gestational age at antenatal care attendance on the successful implementation of a maternal respiratory syncytial virus (RSV) vaccine program in coastal Kenya

BackgroundMaternal immunisation to boost respiratory syncytial virus (RSV) specific antibodies in pregnant women is a strategy to enhance infant protection. The timing of maternal vaccination during pregnancy may be critical for its effectiveness. However, Kenya has no documented published data on gestational age distribution of pregnant women attending antenatal care (ANC), or the proportion of women attending ANC during the proposed window period for vaccination, to inform appropriate timing for delivery or estimate potential uptake of this vaccine.MethodsA cross-sectional survey was conducted within the Kilifi Health and Demographic Surveillance System (KHDSS), coastal Kenya. A simple random sample of 1000 women who had registered pregnant in 2017 to 2018 and with a birth outcome by the time of data collection was taken. The selected women were followed at their homes, and individually written informed consent was obtained. Records of their antenatal attendance during pregnancy were abstracted from their ANC booklet. The proportion of all pregnant women from KHDSS (55%) who attended for one or more ANC in 2018 was used to estimate vaccine coverage.ResultsOf the 1000 women selected, 935 were traced with 607/935 (64.9%) available for interview, among whom 470/607 (77.4%) had antenatal care booklets. The median maternal age during pregnancy was 28.6 years. The median (interquartile range) gestational age in weeks at the first to fifth ANC attendance was 26 (21–28), 29 (26–32), 32 (28–34), 34 (32–36) and 36 (34–38), respectively. The proportion of women attending for ANC during a gestational age window for vaccination of 28–32 weeks (recommended), 26–33 weeks and 24–36 weeks was 76.6% (360/470), 84.5% (397/470) and 96.2% (452/470), respectively. Estimated vaccine coverage was 42.1, 46.5 and 52.9% within the narrow, wide and wider gestational age windows, respectively.ConclusionsIn a random sample of pregnant women from Kilifi HDSS, Coastal Kenya with card-confirmed ANC clinic attendance, 76.6% would be reached for maternal RSV vaccination within the gestational age window of 28–32 weeks. Widening the vaccination window (26–33 weeks) or (24–36 weeks) would not dramatically increase vaccine coverage and would require consideration of antibody kinetics data that could affect vaccine efficacy.

Routine Vaccination Coverage - Worldwide, 2019.

Endorsed by the World Health Assembly in 2020, the Immunization Agenda 2030 strives to reduce morbidity and mortality from vaccine-preventable diseases across the life course (1). This report, which updates previous reports (2), presents global, regional,* and national vaccination coverage estimates and trends as of 2019 and describes the number of surviving infants who did not receive the first dose of diphtheria and tetanus toxoids and pertussis-containing vaccine (DTP1) during the first year of life (i.e., zero-dose children), which serves as a proxy for children with poor access to immunization and other health services. Global estimates of coverage with the third dose of DTP (DTP3), the first dose of measles-containing vaccine (MCV1), and the third dose of polio vaccine (Pol3) ranged from 84% to 86% during 2010-2019. Worldwide, 19.7 million children (15%) were not vaccinated with DTP3 in 2019, 13.8 million (70%) of whom were zero-dose children. During 2010-2019, the number of zero-dose children increased in the African, Americas, and Western Pacific regions. Global coverage with the second MCV dose (MCV2) increased from 42% in 2010 to 71% in 2019. During 2010-2019, global coverage with underused vaccines increased for the completed series of rotavirus vaccine (rota), pneumococcal conjugate vaccine (PCV), rubella-containing vaccine (RCV), Haemophilus influenzae type b vaccine (Hib), hepatitis B vaccine (HepB), and human papillomavirus vaccine (HPV). Achieving universal coverage with all recommended vaccines will require tailored, context-specific strategies to reach communities with substantial proportions of zero-dose and incompletely vaccinated children, particularly those in remote rural, urban poor, and conflict-affected communities (3).

Estimated influenza illnesses and hospitalizations averted by influenza vaccination among children aged 6–59 months in Suzhou, China, 2011/12 to 2015/16 influenza seasons

BackgroundThere are few estimates of vaccination-averted influenza-associated illnesses in China. MethodsWe used a mathematical model and Monte Carlo algorithm to estimate numbers and 95% confidence intervals (CI) of influenza-associated outcomes (hospitalization, illness, and medically-attended (MA) illness) averted by vaccination among children aged 6–59 months in Suzhou from October 2011–September 2016. Influenza illnesses included non-hospitalized MA influenza illnesses and non-MA influenza illnesses. The numbers of influenza-associated outcomes averted by vaccination were the difference between the expected burden if there were no vaccination given and the observed burden with vaccination. The model incorporated the disease burden estimated based on surveillance data from Suzhou University Affiliated Children’s Hospital (SCH) and data from health utilization surveys conducted in the catchment area of SCH, age-specific estimates of influenza vaccination coverage in Suzhou from the Expanded Program on Immunization database, and influenza vaccine effectiveness estimates from previous publications. Averted influenza estimations were presented as absolute numbers and in terms of the prevented fraction (PF). A hypothetical scenario with 50% coverage (but identical vaccine effectiveness) over the study period was also modeled. ResultsIn ~250,000 children, influenza vaccination prevented an estimated 731 (CI: 549–960) influenza hospitalizations (PF: 6.2% of expected, CI: 5.8–6.6%) and 10,024 (7593–12,937) influenza illnesses (PF: 6.5%, 6.4–6.7%), of which 8342 (6338–10,768) were MA (PF: 6.6%, 6.4–6.7%) from 2011 to 2016. The PFs declined each year along with decreasing influenza vaccination coverage. If 50% of the study population had been vaccinated over time, the estimated numbers of averted cases during the study period would have been 4059 (3120–5762) influenza hospitalizations (PF: 27.2%, 26.4–27.9%) and 56,215 (42,925–78,849) influenza illnesses (PF: 28.5%, 28.3–28.7%), of which 46,596 (35,662–65,234) would be MA (PF: 28.5%, 28.3–28.7%). ConclusionInfluenza vaccination is estimated to have averted influenza-associated illness outcomes even with low coverage in children aged 6–59 months in Suzhou. Increasing influenza vaccination coverage in this population could further reduce illnesses and hospitalizations.

Vaccination Coverage by Age 24 Months Among Children Born in 2016 and 2017 — National Immunization Survey-Child, United States, 2017–2019

Immunization has been described as a "global health and development success story," and worldwide is estimated to prevent 2-3 million deaths annually.* In the United States, the Advisory Committee on Immunization Practices (ACIP) currently recommends vaccination against 14 potentially serious illnesses by the time a child reaches age 24 months (1). CDC monitors coverage with ACIP-recommended vaccines through the National Immunization Survey-Child (NIS-Child); data from the survey were used to estimate vaccination coverage at the national, regional, state, territorial, and selected local area levels† among children born in 2016 and 2017. National coverage by age 24 months was ≥90% for ≥3 doses of poliovirus vaccine, ≥3 doses of hepatitis B vaccine (HepB), and ≥1 dose of varicella vaccine (VAR); national coverage was ≥90% for ≥1 dose of measles, mumps, and rubella vaccine (MMR), although MMR coverage was <90% in 14 states. Coverage with ≥2 doses of influenza vaccine was higher for children born during 2016-2017 (58.1%) than for those born during 2014-2015 (53.8%) but was the lowest among all vaccines studied. Only 1.2% of children had received no vaccinations by age 24 months. Vaccination coverage among children enrolled in Medicaid or with no health insurance was lower than that among children who were privately insured. The prevalence of being completely unvaccinated was highest among uninsured children (4.1%), lower among those enrolled in Medicaid (1.3%), and lowest among those with private insurance (0.8%). The largest disparities on the basis of health insurance status occurred for ≥2 doses of influenza vaccine and for completion of the rotavirus vaccination series. Considering the disruptions to health care provider operations caused by the coronavirus disease 2019 (COVID-19) pandemic, extra effort will be required to achieve and maintain high levels of coverage with routine childhood vaccinations. Providers, health care entities, and public health authorities can communicate with families about how children can be vaccinated safely during the pandemic, remind parents of vaccinations that are due for their children, and provide all recommended vaccinations to children during clinic visits. This will be especially important for 2020-21 seasonal influenza vaccination to mitigate the effect of two potentially serious respiratory viruses circulating in the community simultaneously.

How much does it cost to measure immunity? A costing analysis of a measles and rubella serosurvey in southern Zambia.

Serosurveys are a valuable surveillance tool because they provide a more direct measure of population immunity to infectious diseases, such as measles and rubella, than vaccination coverage estimates. However, there is concern that serological surveys are costly. We adapted a framework to capture the costs associated with conducting a serosurvey in Zambia. We costed a nested serosurvey in Southern Province, Zambia that collected dried blood spots from household residents in a post-campaign vaccine coverage survey. The financial costs were estimated using an ingredients-based costing approach. Inputs included personnel, transportation, field consumable items, social mobilization, laboratory supplies, and capital items, and were classified by serosurvey function (survey preparation, data collection, biospecimen collection, laboratory testing, and coordination). Inputs were stratified by whether they were applicable to surveys in general or attributable specifically to serosurveys. Finally, we calculated the average cost per cluster and participant. We estimated the total nested serosurvey cost was US $68,558 to collect dried blood spots from 658 participants in one province in Zambia. A breakdown of the cost by serosurvey phase showed data collection accounted for almost one third of the total serosurvey cost (32%), followed by survey preparation (25%) and biospecimen collection (20%). Analysis by input categories indicated personnel costs were the largest contributing input to overall serosurvey costs (51%), transportation was second (23%), and field consumables were third (9%). By combining the serosurvey with a vaccination coverage survey, there was a savings of $43,957. We estimated it cost $4,285 per average cluster and $104 per average participant sampled. Adding serological specimen collection to a planned vaccination coverage survey provided a more direct measurement of population immunity among a wide age group but increased the cost by approximately one-third. Future serosurveys could consider ways to leverage existing surveys conducted for other purposes to minimize costs.

Genomic Characterization of Invasive Meningococcal Serogroup B Isolates and Estimation of 4CMenB Vaccine Coverage in Finland.

Invasive meningococcal disease (IMD) caused by Neisseria meningitidis is a significant cause of morbidity and mortality worldwide. In Finland, the incidence rate of IMD is low, with meningococcal serogroup B (MenB) accounting for around one-third of IMD cases annually. The aim of this study was to investigate the genetic variability of invasive MenB isolates collected in Finland between 2010 and 2017 (n = 81), including the genes encoding the 4-component MenB vaccine (4CMenB; Bexsero; GSK) antigens and their promoters, and to evaluate the 4CMenB potential coverage. Whole-genome sequencing was performed. The meningococcal antigen typing system (MATS) was used to characterize MenB isolates and predict the potential coverage of 4CMenB. MATS was complemented by genetic MATS (gMATS) through association of antigen genotyping and phenotypic MATS results. Multilocus sequence typing revealed predominance of the ST-41/44 clonal complex among which sequence type (ST)-303 was the most common and was predicted to be covered by 4CMenB. Of the 4 major vaccine antigens, the factor H-binding protein variant 1, neisserial heparin binding antigen peptide 2, and the PorA P1.4 antigen were predominant, whereas Neisseria adhesin A was present in only 4% of the 81 isolates. MATS and gMATS 4CMenB strain coverage predictions were 78% and 86%, respectively, in a subpanel of 60 isolates collected during 2010 to 2014, with a gMATS prediction of 84% for all 81 isolates. The results suggest that 4CMenB could reduce the burden of IMD in Finland and that gMATS could be applied to monitor vaccine strain coverage and predict vaccine effectiveness.IMPORTANCE 4CMenB is a 4-component vaccine used against invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup B (MenB). We investigated the genetic variability of MenB in Finland and evaluated 4CMenB strain coverage by 2 different methods: MATS (meningococcal antigen typing system) and gMATS (genetic MATS). In a set of MenB isolates, 78% (MATS) and 86% (gMATS) were predicted as covered by 4CMenB, suggesting that use of 4CMenB would help reduce IMD incidence in Finland. MATS has been used in 13 countries worldwide, generating information on phenotypic characteristics that could infer protection by 4CMenB. Based on these data and genetic information, gMATS coverage predictions can be made. gMATS predicts coverage consistent with MATS for about 94% of tested strains. Unlike MATS, gMATS does not require live isolates, thus allowing the analysis also of noncultivable strains, making the coverage predictions more accurate. Therefore, gMATS can replace MATS to assess 4CMenB coverage, including in regions with no prior MATS data.

Coberturas de vacunación en tiempos de COVID-19: Un análisis desde la epidemiología social en la región del Cusco

Introducción: La pandemia por COVID-19 podría haber afectado la cobertura de vacunación. Objetivo: Estimar las coberturas de vacunación para los años 2018-2020 y analizar las condiciones sociales, económicas y educativas relacionadas a este indicador. Material y Métodos: Estudio epidemiológico social realizado en la región Cusco con reporte de cobertura de vacunación en los años 2018-2020 para el periodo enero – mayo y con indicadores económicos y educativos para el 2019. Se estimaron tasas de cobertura de vacunación (pentavalente, antipoliomielítica, antineumocócica y SPR) así como variables de desigualdad. Se expresaron métricas de brecha a través de índices de Kuznets absoluto (ika) y Kuznets relativo (ikr). Resultados: De 112 distritos, las coberturas de vacunación para las 4 vacunas fueron en promedio de 39%, 38% y 24% para el 2018, 2019 y 2020; respectivamente. Las coberturas de vacunación acumulada son similares entre el 2018 y 2019 según estratificador educativo y económico, pero en todos los quintiles del 2020 hubo disminución de las coberturas en un 40% aproximadamente. En los años 2019 y 2020 según escolaridad, las diferencias absolutas y relativas entre los quintiles extremos se invierten, siendo mayor las coberturas en los quintiles con menor escolaridad en comparación con los de mayor escolaridad. Conclusión: Existe disminución de tasas de cobertura de vacunación acumulada para el 2020 y se diferencian según quintiles de escolaridad e ingreso, lo cual se atribuye al estado de emergencia sanitaria debido a COVID-19. Es crítico vigilar las actividades de recuperación de cobertura de vacunación para evitar brotes de enfermedades inmunoprevenibles.

Impact of population aging on the burden of vaccine-preventable diseases among older adults in the United States

ABSTRACT Despite vaccination recommendations, the burden of vaccine-preventable diseases remains high in older adults in the United States (US), contributing to substantial morbidity, mortality, and health care resource use and costs. To adequately plan for health care resource needs and to help inform vaccination policies, burden of disease projections that account for population aging over the coming decades are needed. As a first step, this exploratory study projects the burden of influenza, pertussis, herpes zoster, and pneumococcal disease in adults aged 50 y and older in the US, using a population-based modeling framework with separate decision trees for each vaccine-preventable disease. The model uses projected population estimates from the US Census Bureau to account for changes in the US population over time and then calculates expected numbers of cases and associated costs for each disease, keeping current estimates of age-specific disease incidence, vaccine coverage, and efficacy constant over time. This approach was used to focus the exploratory analysis on the burden of disease that may be expected due to population changes alone, assuming that all else remains unchanged. Due to population growth and the shifting age distribution over the next 30 y, the annual societal economic burden for the four vaccine-preventable diseases is projected to increase from approximately $35 billion to $49 billion, resulting in cumulative costs of approximately $1.3 trillion, as well as more than 1 million disease-related deaths. Given such notable burden, further efforts to increase vaccination coverage and effectiveness in older adults are needed.