Estimating global changes in routine childhood vaccination coverage during the COVID-19 pandemic, 2020–2021

ObjectivesThe COVID-19 pandemic has disrupted the distribution of routine immunizations globally. Multi-country studies assessing a wide spectrum of vaccines and their coverage rates are needed to determine global performance in achieving vaccination goals.MethodsGlobal vaccine coverage data for 16 antigens were obtained from WHO/UNICEF Estimates of National Immunization Coverage. Tobit regression was performed for all country-antigen pairs for which data were continuously available between 2015–2020 or 2015–2021 to predict vaccine coverage in 2020/2021. Vaccines for which multi-dose data were available were assessed to determine whether vaccine coverage for subsequent doses were lower than that of first doses.ResultsVaccine coverage was significantly lower-than-predicted for 13/16 antigens in 2020 and all assessed antigens in 2021. Lower-than-predicted vaccine coverage was typically observed in South America, Africa, Eastern Europe, and Southeast Asia. There was a statistically significant coverage drop for subsequent doses of the diphtheria-tetanus-pertussis, pneumococcus, and rotavirus vaccines compared to first doses in 2020 and 2021.ConclusionThe COVID-19 pandemic exerted larger disruptions to routine vaccination services in 2021 than in 2020. Global efforts will be needed to recoup vaccine coverage losses sustained during the pandemic and broaden vaccine access in areas where coverage was previously inadequate.     

The impact of the COVID-19 pandemic on vaccine coverage in Kilifi,Kenya: A retrospective cohort study

The COVID-19 pandemic caused unprecedented disruption in health service delivery, globally. This study sought to provide evidence on the impact of the pandemic on vaccine coverage in Kilifi County, Kenya. We conducted a vaccine coverage survey between April and June 2021 within the Kilifi Health and Demographic Surveillance System (KHDSS). Simple random sampling was used to identify 1500 children aged 6 weeks–59 months. Participants were grouped into three retrospective cohorts based on when they became age-eligible for vaccination: before the pandemic, during the first year, or during the second year of the pandemic. Survival analysis with Cox regression was used to evaluate the association between the time-period at which participants became age-eligible for vaccination and the rate of vaccination within a month of age-eligibility for the third dose of pentavalent vaccine (Pentavalent-3) and within three months of age-eligibility for the first dose of Measles vaccine (MCV-1). A total of 1,341 participants were included in the survey. Compared to the pre-COVID-19 baseline period, the rate of vaccination within a month of age-eligibility for Pentavalent-3 was not significantly different in the first year of the pandemic (adjusted hazard ratio [aHR] 1.03, 95 % confidence interval [CI] 0.90–1.18) and was significantly higher during the second year of the pandemic (aHR 1.33, 95 % CI 1.07–1.65). The rate of vaccination with MCV-1 within three months of age-eligibility was not significantly different among those age-eligible for vaccination during the first year of the pandemic (aHR 1.04, 95 % CI 0.88–1.21) and was 35 % higher during the second year of the pandemic (95 % CI 1.11–1.64), compared to those age-eligible pre-COVID-19. After adjusting for known determinants of vaccination, the COVID-19 pandemic did not adversely affect the rate of vaccination within the KHDSS.     

Routine childhood vaccination programme coverage,El Salvador, 2011—In search of timeliness

While assessing immunization programmes, not only vaccination coverage is important, but also timely receipt of vaccines. We estimated both vaccination coverage and timeliness, as well as reasons for non-vaccination, and identified predictors of delayed or missed vaccination, for vaccines of the first two years of age, in El Salvador.     

The impact of the COVID-19 pandemic on parents’ perceptions and acceptance of routine childhood vaccination in Canada: A national longitudinal study

BackgroundA decline in routine vaccination was reported by some countries early in the COVID-19 pandemic. In the context of the pandemic, determinants of routine childhood vaccination may have changed. Changes over time in parents’ perceptions of routine vaccines and intentions for their children during the pandemic have not been fully explored. Understanding changes provides opportunities to promote routine childhood vaccines and address factors that may compromise parents’ acceptance.MethodsWe conducted longitudinal analysis of two sequential national surveys during the pandemic (Dec 2020 and Oct/Nov 2021) to assess changes over time in Canadian parents’ perceptions of routine childhood vaccines, intentions to vaccinate, access for their children ≤ 17 years, and differences among sociodemographic characteristics. McNemar-Bowker tests were used to determine changes in parents’ responses collected at two time points.ResultsOf the 650 parents in the sample, 25.1% with a child ≤ 6 years and 20.5% with a child 7–17 years perceived that routine childhood vaccines were more important because of the pandemic. Between the two time points, parents’ confidence in the safety (72.8% to 80.2%, p <.001) and effectiveness (81.7% to 85.2%, p =.007) of routine vaccines increased, parents were more engaged in vaccine decision-making (73.4% to 79.8%, p =.006), and everyday stress preventing vaccination decreased (78.8% to 68.5%, p <.001). Acceptance of routine vaccines increased (82.9% to 86.5%, p =.021), but more parents were undecided about influenza vaccination (12.6% to 20.3%, p =.002). Compared to parents with 1 child, those with 2 children reported increased vaccination acceptance (82.6% to 87.4%, p =.024).InterpretationUnder the spotlight of COVID-19, parents’ confidence in routine vaccines, engagement in decision-making, and vaccination acceptance increased. Vaccination providers should support parents’ decision-making as they navigate routine childhood vaccine uncertainties. Differences in parents’ acceptance of routine and influenza vaccines for their children highlight the need for targeted communication strategies for specific vaccines.     

Routine childhood vaccination in India from 2005–2006 to 2015–2016: Temporal trends and geographic variation

ObjectiveIndia has experienced a substantial increase in the coverage of routine childhood vaccines in recent years. However, a large fraction of these vaccines is not delivered in a timely manner, i.e., at the recommended age. Further, substantial disparities exist in both coverage and timeliness across states. We aim to quantify the changes in coverage and timeliness of routine childhood vaccination in India over time, their variation across states, and changes in these variations over time.MethodsWe used data from two rounds of India’s National Family Health Surveys, NFHS-3 (2005–06) and NFHS-4 (2015–16) on bacille Calmette–Guerin vaccine (BCG), three doses of diphtheria, pertussis, and tetanus vaccine (DPT1, DPT2, DPT3), and measles-containing vaccine (MCV). We used the Turnbull estimator to estimate the cumulative distribution function (CDF) of administering each vaccine by a certain age while accounting for two-sided censoring in the survey data. We then used these estimated CDFs to calculate coverage and timeliness at the national and state levels.FindingsAt the national level, both vaccination coverage and timeliness estimates increased from NFHS-3 to NFHS-4 for all vaccines. The increase in timeliness ranging from 27.3% for DPT3 to 74.0% for MCV continued to be lower than coverage, ranging from 75.3% (95% CI 57.7–87.2) for DPT3 to 74.0% (95% CI 42.2–33.0) for MCV, for all vaccines. Cross-state variation in timeliness was greater than the variation in coverage. Variation in both timeliness and coverage reduced from NFHS-3 to NFHS-4. However, this reduction was greater for timeliness than for coverage.ConclusionsA large fraction of the children in India receive vaccines later than the recommended age thereby keeping them exposed to vaccine-preventable diseases. Interventions that specifically focus on improving the timely delivery of vaccines are needed to improve the overall effectiveness of the routine immunization program.     

Short term impact of the COVID-19 pandemic on incidence of vaccine preventable diseases and participation in routine infant vaccinations in the Netherlands in the period March-September 2020

We aimed to assess the impact of the COVID-19 pandemic on the incidence of vaccine-preventable diseases (VPDs) and participation in the routine infant vaccination programme in the Netherlands. The incidence of various VPDs initially decreased by 75–97% after the implementation of the Dutch COVID-19 response measures. The participation in the first measles-mumps-rubella vaccination among children scheduled for vaccination in March-September 2020 initially dropped by 6–14% compared with the previous year. After catch-up vaccination, a difference in MMR1 participation of ?1% to ?2% still remained. Thus, the pandemic has reduced the incidence of several VPDs and has had a limited impact on the routine infant vaccination programme.     

武进区儿童免疫规划疫苗接种率调查

目的 了解武进区儿童免疫规划疫苗接种率.方法 PPS,调查30个行政村的适龄儿童,应用SPSS13.0进行统计分析.结果 共调查1142名适龄儿童,本地儿童464人,流动儿童678人.建卡率99.56％,5苗合格接种率BCG95.27％,OPV 94.05％,DPT 92.29％,MV 91.24％,HepB 91.94％.4苗及时接种率BCG 73.73％,MV 81.61％,OPV82.40％,HepB首针82.84％.结论 本地儿童5苗合格接种率、4苗及时接种率高于流动儿童,差异有统计学意义.父亲或母亲文化程度不同、家庭经济情况不同,儿童5苗合格接种率有差异.     

重庆市2002年常规免疫接种率报告及监测情况分析

目的：了解重庆市儿童常规免疫接种情况，对全市2002年常规免疫接种率报告监测系统提供的数据进行分析评价。结果：2002年全市常规免疫接种卡介苗、口服脊髓灰质炎疫苗、百白破混合制剂、麻疹疫苗、乙型肝炎疫苗等5种疫苗的报告接种率均在90％以上，估算接种率为55．6％～85．4％；部分区县报告接种率可信性较低。结论：进一步搞好常规免疫接种率报告的同时，需加强常规免疫薄弱地区的计划免疫工作。     

内蒙古自治区2011年常规免疫接种率监测结果评价

目的了解内蒙古自治区2011年常规免疫接种情况,对常规免疫接种率监测结果进行评价。方法通过差值法和比值法对监测结果进行比较分析。结果内蒙古全区卡介苗(BCG)、百白破疫苗(DPT)、乙肝疫苗(HepB)、脊髓灰质炎疫苗(PV)、麻类疫苗(MCV)和乙脑疫苗(JE)六苗常规免疫报告接种率均高于99%,估算接种率均小于95%。全区D值评价为不可信,R值评价为可信。结论内蒙古常规免疫接种率报告真实性、准确性有待提高。     

湖北省2004年常规免疫监测结果评价

目的评价湖北省2004年常规免疫接种率监测结果。方法对湖北省2004年常规免疫监测报表进行估计接种率、差值评价、比值评价和报表及时性、完整性分析。结果湖北省2004年常规免疫监测报表及时性、完整性较以往明显提高;四苗基础和加强免疫报告接种率为92．34％（麻疹疫苗,MV2）～98．98％（口服脊髓灰质炎疫苗,OPV）,（乙型肝炎疫苗,HBV）报告接种率为98．67％;四苗基础免疫估计接种率为78．73％（卡介苗,BCG）～83．65％（MV）,HBV为74．57％;加强免疫估计接种率分别为7．35％（MV2）～73．05％（白喉、百日咳、破伤风混合疫苗,DPT）。结论差值评价说明湖北省报告接种率可信性较低,比值评价说明数据可疑;今后需加强常规免疫规范化管理。     

Vaccination coverage in Haiti: results from the 2009 national survey

Introduction

Since 1977, vaccinations to protect against tuberculosis, diphtheria, tetanus, pertussis, polio, and measles (and rubella since 2009) have been offered to children in Haiti through the routine immunization program. From April to July 2009, a national vaccination coverage survey was conducted to assess the success of the routine immunization program at reaching children in Haiti.

Methods

A multi-stage cluster survey was conducted using a modified WHO method for household sampling. A standardized questionnaire was administered to collect vaccination histories, demographic information, and reasons for under-vaccination of children aged 12–23 months. A child who received the eight recommended routine vaccinations was considered fully vaccinated. The routine vaccination schedule was used to define valid doses and estimate the percentage of children vaccinated on time.

Results

Among 1345 children surveyed, 40.4% (95% CI: 36.6–44.2) of the 840 children with vaccination cards had received all eight recommended vaccinations. Coverage was highest for the Bacille Calmette–Guérin vaccine (87.3%), the first doses of the diphtheria–tetanus–pertussis vaccine (92.0%), and oral poliovirus vaccine (93.4%) and lowest for measles vaccine (46.9%). Timely vaccination rates were lower. Assuming similar coverage for the 505 children without cards, coverage with the complete vaccination series among all surveyed children 31.9%. Reasons for under-vaccination included not having enough time to reach the vaccination location (24.8%), having a child who was ill (13.8%), and not knowing when, or forgetting, to go for vaccination (12.8%).

Conclusions and recommendations

Coverage for early-infant vaccines was high; however, most children did not complete the full vaccination series, and many children received vaccinations later than recommended. Efforts to improve the immunization program should include increasing the frequency of outreach services, training for vaccination staff to minimize missed opportunities, and better communicating the timing of vaccinations to encourage caregivers to bring their children for vaccinations at the recommended age. Efforts to promote the benefits of vaccination and card retention are also needed.     

2012年潍坊市1～6岁儿童11种免疫规划疫苗接种率调查

目的了解潍坊市儿童免疫规划疫苗的接种状况,为进一步做好免疫规划工作提供科学依据。方法2012年12月,采用分层随机抽样方法,在潍坊市所辖12个县（市、区）抽取2006年1月1日至2011年12月31日出生的儿童进行11种免疫规划疫苗的接种状况调查。结果调查儿童2160名（常住儿童1440名、流动儿童720名）,BCG、HepB、OPV123、DPT123、MV初种、MenA、JE—11、MMR、DPT4、HepA—I、JE—12、OPV4、MenAC1、MenAC2、DT、MV3合格接种率,分别为98．89％、99．26％、99．03％、98．94％、99．03％、98．70％、98．56％、98．61％、98．67％、96．61％、96．50％、95．09％、95．49％、85．56％、84．17％、87．50％。6岁年龄组MenACz、DT、MV3常住儿童与流动儿童合格接种率差异均有统计学意义（P〈0．01）。BCG、HepB、OPV123、DPT123、MV初种、MenA、JE—I1、MMR、DPT4、HepA—I、JE—12、0PV4、MenACl合格接种率,常住儿童与流动儿童接种率差异均无统计学意义（P〉o．05）。结论2012年潍坊市1～6岁儿童11种免疫抑训瘩苗的椿种室掂高     

2008—2012年淄博市张店区马尚镇入托入学儿童接种证查验情况调查

目的了解2008—2012年淄博市张店区马尚镇入托入学接种证查验情况,为做好免疫规划管理提供依据。方法收集2008—2012年入托入学儿童预防接种证现场查验相关资料,采用Excel、SPSS 19.0进行统计分析。结果共查验本地入托儿童8023名,持证率98.99%,持卡率95.26%,外地入托儿童670名,持证率94.18%,持卡率89.85%。查验本地入学儿童6591名,持证率94.10%,持卡率91.62%,外地入学儿童735名,持证率90.34%,持卡率87.35%。结论加强儿童家长免疫规划知识教育,提高长期保存接种证、接种卡意识,及时、全程接种疫苗。