Increasing vaccination coverage: The school entry vaccination record check program in Guizhou Province China, 2003–2018

BackgroundGuizhou Province of China implements a vaccination program specifying that children’s vaccination records are to be checked upon entry to kindergarten and primary school; children missing one or more recommended vaccinations are to be offered the missed vaccinations; school-level vaccination coverage levels are assessed at the time of school enrollment and six months later to monitor compliance rates.MethodsWe obtained the number of doses of each vaccine in the national immunization schedule that were administered before and six months after kindergarten and school enrollment and reported to Guizhou Province during 2004 through 2018. We determined temporal trends in coverage of the second dose of measles-containing vaccine (MCV2) and other vaccines, incidence of measles, and number of school-based measles outbreaks.ResultsMCV2 coverage at kindergarten entry increased from 53% in 2004 to 98% in 2018. Among children missing one or more vaccinations, the six-month catch-up rate of MCV2 increased from 80% in 2004 to 99% in 2018. Among primary school children, coverage of MCV2 and other recommended vaccines had similar increases. The annual incidence of measles among Guizhou’s total population declined from 280 per million in 2003 to 0.3 per million in 2018. There have been no measles outbreaks in kindergartens or schools since 2015.ConclusionsChecking vaccination record at kindergartens and primary schools and providing necessary catch-up vaccination was associated with increased coverage of measles and other vaccines, lower incidence of measles, and an apparent end to school-based measles outbreaks. Guizhou’s experience of checking vaccination records at school enrollment led to implementation of this strategy in other provinces. In 2019, the kindergarten and school entry vaccination record check program was incorporated into China’s national vaccine law.     

Trends in school-level vaccination coverage from 2015 to 2018: Increases in exemption rates and declines in herd immunity in Arizona

Vaccination enrollment requirements are an important tool used to improve vaccination coverage among school-aged children. However, all states permit varying exemptions that allow students to stay enrolled without receiving some (or all) vaccinations. In Arizona, schools are required to report vaccination data on their kindergarten and 6th grade students annually to the Arizona Department of Health Services (ADHS). We analyzed trends in herd immunity and personal belief exemptions in Arizona schools from 2015 to 2018. We also identified multiple correlates of herd immunity at the school level. Our results demonstrate decreased herd immunity statewide and by school type and an increased rate of personal belief exemptions during this period. These findings contribute to the body of literature suggesting that vaccine hesitancy is growing, resulting in suboptimal vaccination coverage for children. Moreover, this research has several policy implications, especially for states permitting multiple exemption types and lax exemption criteria.     

Vaccination coverage and immunity levels against vaccine-preventable diseases in male Air Force recruits in Greece

AimData about susceptibility rates in young adults are scarce. We estimated the complete vaccination rates, timeliness of vaccinations and susceptibility rates among male military recruits in Greece.MethodsA standardized form was used to collect data. Immunity against measles, rubella, varicella, hepatitis A and hepatitis B was serologically estimated.ResultsWe studied 385 recruits with a mean age of 23.5 years (range: 18.3–29.9 years). Complete vaccination rates were 94.3% for measles, 100% for rubella, 15% for varicella, 73.9% for hepatitis A and 96.5% for hepatitis B. Only 10.8% of participants were fully vaccinated against all five diseases. Timely vaccination was 47.2% for measles, 89.3% for rubella and 48.1% for hepatitis B. Recruits >23 years had a 1.5-fold increased probability for incomplete vaccinations compared to younger recruits. Laboratory-confirmed immunity rates were 80% against measles, 85.7% against rubella, 85.2% against varicella, 69.4% against hepatitis A and 77.1% against hepatitis B. It is estimated that approximately 388,696 persons aged 18–30 years are susceptible to measles, 277,640 persons to rubella, 287,736 persons to varicella, 595,664 persons to hepatitis A and 444,224 persons to hepatitis B in Greece.ConclusionOur study showed that young adults have significant immunity gaps against measles, rubella, varicella, hepatitis A and hepatitis B. Complete vaccination rates were suboptimal against hepatitis A and varicella. Strategies to access young adults and increase immunity rates through catch-up vaccination services should be investigated. A third dose of MMR vaccine should be considered for young adolescents in Greece.     

Mandatory vaccination of infants in France: Is that the way forward?

In this opinion paper, the authors argue that the extension of mandatory immunization of infants up to two years of age from three diseases (diphtheria, tetanus, poliomyelitis) to 11 diseases, introduced in France in January 2018, is not a sustainable response to the challenge of controlling vaccine-preventable diseases. In France in 2017, infant immunization coverage (IC) rates were sufficiently high or increasing (hepatitis B), except for measles, mumps and rubella (MMR) and meningococcus C disease. Even if vaccination obligation makes it possible to achieve the MMR IC objectives among infants, communication programmes and supported advice from GPs are essential for the catch-up of susceptible adults to obtain herd immunity. The impact of mandatory immunization on hesitancy remains uncertain, and it contradicts the evolution of the patient’s role in the governance of his own health and the principle of autonomy. Numerous studies have shown that interventions and advice from health professionals improve vaccine acceptance. To correct the poor implementation of some vaccination programmes by health professionals, strong communication and resources from health authorities are needed, rather than a retreat towards obligation. Reducing missed opportunities and increasing access to immunization are essential objectives. Finally, an immunization policy based on primary care and a patient-centred approach to each vaccination are more likely to reduce vaccine hesitancy, sustainably.     

Sero-epidemiology of measles and mumps in Korea: impact of the catch-up campaign on measles immunity

A catch-up campaign targeting children aged 8–16 years using measles–rubella (MR) vaccine was conducted during 2001 in Korea. To evaluate the impact of the campaign and assess mumps immunity, human IgG antibodies were detected using ELISA for measles (5826 samples) and mumps (5890 samples) in a national sample of opportunistically collected sera from a population aged 0–34 years. The measles immunity increased by 5–10% following the catch-up campaign in the targeted age group. Infants lost maternal antibodies rapidly and about 90% of infants were susceptible to measles and mumps at 6–8 months of life. The sero-prevalence of mumps antibody increased slowly with age and stabilized at a lower level when compared with that of measles. Despite an immediate reduction in susceptibility among the targeted age group of the catch-up campaign, continuous efforts to increase immunization coverage are needed to interrupt indigenous measles transmission. Furthermore, our results suggest continuous mumps outbreaks could occur because of the accumulation of susceptible individuals.     

Use of catch-up vaccinations in the second year of life (2YL) platform to close immunity gaps: A secondary DHS analysis in Pakistan,Philippines, and South Africa

BackgroundImmunity gaps caused by COVID-19-related disruptions highlight the importance of catch-up vaccination. Number of countries offering vaccines in second year of life (2YL) has increased, but use of 2YL for catch-up vaccination has been variable. We assessed pre-pandemic use of 2YL for catch-up vaccination in three countries (Pakistan, the Philippines, and South Africa), based on existence of a 2YL platform (demonstrated by offering second dose of measles-containing vaccine (MCV2) in 2YL), proportion of card availability, and geographical variety.MethodsWe conducted a secondary data analysis of immunization data from Demographic and Health Surveys (DHS) in Pakistan (2017–2018), the Philippines (2017), and South Africa (2016). We conducted time-to-event analyses for pentavalent vaccine (diphtheria-tetanus-pertussis-Hepatitis B-Haemophilus influenzae type b [Hib]) and MCV and calculated use of 2YL and MCV visits for catch-up vaccination.ResultsAmong 24–35-month-olds with documented dates, coverage of third dose of pentavalent vaccine increased in 2YL by 2%, 3%, and 1% in Pakistan, Philippines, and South Africa, respectively. MCV1 coverage increased in 2YL by 5% in Pakistan, 10% in the Philippines, and 3% in South Africa. In Pakistan, among 124 children eligible for catch-up vaccination of pentavalent vaccine at time of a documented MCV visit, 45% received a catch-up dose. In the Philippines, among 381 eligible children, 38% received a pentavalent dose during an MCV visit. In South Africa, 50 children were eligible for a pentavalent vaccine dose before their MCV1 visit, but only 20% received it; none with MCV2.ConclusionSmall to modest vaccine coverage improvements occurred in all three countries through catch-up vaccination in 2YL but many missed opportunities for vaccination continue to occur. Using the 2YL platform can increase coverage and close immunity gaps, but immunization programmes need to change policies, practices, and monitor catch-up vaccination to maximize the potential.     

Sero-epidemiology of measles and mumps in Korea: impact of the catch-up campaign on measles immunity

A catch-up campaign targeting children aged 8-16 years using measles-rubella (MR) vaccine was conducted during 2001 in Korea. To evaluate the impact of the campaign and assess mumps immunity, human IgG antibodies were detected using ELISA for measles (5826 samples) and mumps (5890 samples) in a national sample of opportunistically collected sera from a population aged 0-34 years. The measles immunity increased by 5-10% following the catch-up campaign in the targeted age group. Infants lost maternal antibodies rapidly and about 90% of infants were susceptible to measles and mumps at 6-8 months of life. The sero-prevalence of mumps antibody increased slowly with age and stabilized at a lower level when compared with that of measles. Despite an immediate reduction in susceptibility among the targeted age group of the catch-up campaign, continuous efforts to increase immunization coverage are needed to interrupt indigenous measles transmission. Furthermore, our results suggest continuous mumps outbreaks could occur because of the accumulation of susceptible individuals.     

Identifying immunity gaps for measles using Belgian serial serology data

Vaccine-preventable diseases, such as measles, have been re-emerging in countries with moderate to high vaccine uptake. It is increasingly important to identify and close immunity gaps and increase coverage of routine childhood vaccinations, including two doses of the measles-mumps-rubella vaccine (MMR). Here, we present a simple cohort model relying on a Bayesian approach to evaluate the evolution of measles seroprevalence in Belgium using the three most recent cross-sectional serological survey data collections (2002, 2006 and 2013) and information regarding vaccine properties. We find measles seroprevalence profiles to be similar for the different regions in Belgium. These profiles exhibit a drop in seroprevalence in birth cohorts that were offered vaccination at suboptimal coverages in the first years after routine vaccination has been started up. This immunity gap is observed across all cross-sectional survey years, although it is more pronounced in survey year 2013. At present, the COVID-19 pandemic could negatively impact the immunization coverage worldwide, thereby increasing the need for additional immunization programs in groups of children that are impacted by this. Therefore, it is now even more important to identify existing immunity gaps and to sustain and reach vaccine-derived measles immunity goals.     

Evaluating the impact of the HIV pandemic on measles control and elimination

OBJECTIVE: To estimate the impact of the HIV pandemic on vaccine-acquired population immunity to measles virus because high levels of population immunity are required to eliminate transmission of measles virus in large geographical areas, and HIV infection can reduce the efficacy of measles vaccination. METHODS: A literature review was conducted to estimate key parameters relating to the potential impact of HIV infection on the epidemiology of measles in sub-Saharan Africa; parameters included the prevalence of HIV, child mortality, perinatal HIV transmission rates and protective immune responses to measles vaccination. These parameter estimates were incorporated into a simple model, applicable to regions that have a high prevalence of HIV, to estimate the potential impact of HIV infection on population immunity against measles. FINDINGS: The model suggests that the HIV pandemic should not introduce an insurmountable barrier to measles control and elimination, in part because higher rates of primary and secondary vaccine failure among HIV-infected children are counteracted by their high mortality rate. The HIV pandemic could result in a 2-3% increase in the proportion of the birth cohort susceptible to measles, and more frequent supplemental immunization activities (SIAs) may be necessary to control or eliminate measles. In the model the optimal interval between SIAs was most influenced by the coverage rate for routine measles vaccination. The absence of a second opportunity for vaccination resulted in the greatest increase in the number of susceptible children. CONCLUSION: These results help explain the initial success of measles elimination efforts in southern Africa, where measles control has been achieved in a setting of high HIV prevalence.     

麻疹疫苗的使用及小龄儿童麻疹流行现状

麻疹疫苗的使用在预防与控制麻疹方面取得了巨大的成就,在世界大部分地区控制了麻疹的暴发和流行,疫苗高覆盖地区甚至实现了消除麻疹的目标。随着麻疹疫苗使用的推进,小龄儿童麻疹高发已成为广泛使用麻疹疫苗时代麻疹的流行病学特征之一。使用疫苗获得免疫保护的母亲所生婴儿获得的母传抗体水平只有56％,且维持到3～6个月就急剧下降,不足以保护儿童免患麻疹。由于人口流动、疫苗种类及经济落后等因素,导致存在免疫空白人群或者不能及时进行免疫接种,在当地无法形成有效的免疫屏障。在今后控制麻疹的过程中,应该综合考虑母传抗体水平低和常规免疫存在漏洞的因素,提出控制小龄儿童麻疹的针对性控制策略,最终达到消除麻疹的目标。     

Education level modifies parental hesitancy about COVID-19 vaccinations for their children

It is important to encourage parental acceptance of children’s vaccination against COVID-19 to ensure population immunity and mitigate morbidity and mortality. This study drew upon protection motivation theory (PMT) to explore the factors of parental hesitancy about vaccinating their children. A national online survey was performed in China. A total of 2054 Chinese parents of children aged 6–12 years were included in this study. They reported on measures that assessed hesitancy about children’s vaccination against COVID-19, PMT constructs (susceptibility, severity, response efficacy, self-efficacy, and response costs) and sociodemographic characteristics. Chinese parents reported a hesitancy rate of 29.4% for children’s vaccination. Parents with higher level education were more likely to hesitate to vaccinate their children against COVID-19. After controlling for parents’ and children’s demographic variables, logistic regression showed that parents’ hesitancy about their children’s vaccination increased if parents had lower levels of susceptibility, response efficacy or self-efficacy, as well as higher levels of response costs. In addition, a high educational level can significantly increase the promotive effect of response cost and the protective effect of response efficacy on vaccine hesitancy. In conclusion, our findings suggested that PMT can explain parents' vaccine hesitancy and that education level can modify the effect of copying appraisal, but not threat appraisal, on parental hesitancy. This study will help public health officials send targeted messages to parents to improve the rate of COVID-19 vaccination in children aged 6–12 years and thus reach a higher level of immunity in the population.     

Measles susceptibility in children in Karachi, Pakistan

Measles, despite being vaccine preventable is still a major public health problem in many developing countries. We estimated the proportion of measles susceptible children in Karachi, the largest metropolitan city of Pakistan, one year after the nationwide measles supplementary immunization activity (SIA) of 2007-2008. Oral fluid specimens of 504 randomly selected children from Karachi, aged 12-59 months were collected to detect measles IgG antibodies. Measles antibodies were detected in only 55% children. The proportion of children whose families reported receiving a single or two doses of measles vaccine were 78% and 12% respectively. Only 3% of parents reported that their child received measles vaccine through the SIA. Among the reported single dose measles vaccine recipients, 58% had serologic immunity against measles while among the reported two dose measles vaccine recipients, 64% had evidence of measles immunity. Urgent strengthening of routine immunization services and high quality mass vaccination campaigns against measles are recommended to achieve measles elimination in Pakistan.     

Looking ahead: Caregivers’ COVID-19 vaccination intention for children 5 years old and younger using the health belief model

COVID-19 vaccine hesitancy is a significant public health issue. While vaccines are not yet available for children, clinical trials are underway, and children will likely be an important factor in the U.S. reaching herd immunity. However, little research has been conducted to examine parents’ intention to vaccinate their young children for COVID-19.MethodAn online survey with a national U.S. sample of 682 primary caregivers of children under age six assessed variables associated with intention to accept the COVID-19 vaccine for their children from November 13, 2020, to December 8, 2020.ResultsCaregivers whose child received a recent influenza vaccine, as well as those with previous experience COVID-19, were more likely to express COVID-19 vaccination intention for their young child. Identifying as female was associated with lower COVID-19 vaccination intention, while identifying as Hispanic or Latino was associated with higher intention. Health Belief Model variables of perceived severity of COVID-19 for their child, as well as vaccine confidence, were positive predictors of COVID-19 vaccine intention and mediated the relationship between prior behavior, demographic variables, and intention.ConclusionsThe findings highlight the importance of early, proactive COVID-19 vaccination education efforts directed at caregivers, including those with young children. Vaccines for young children will likely become a necessary part of ending the pandemic’s impact in school settings. Operationally, COVID-19 vaccination may also become a part of childhood vaccination schedules. Understanding the beliefs and intentions of caregivers of young children before vaccinations are recommended for children will enable public health officials and medical practitioners to prepare in advance.     

Economic analysis of measles elimination program in the Republic of Korea, 2001: A cost benefit analysis study

Background

In this study, we modeled the cost benefit analysis for three different measles vaccination strategies based upon three different measles-containing vaccines in Korea, 2001. We employed an economic analysis model using vaccination coverage data and population-based measles surveillance data, along with available estimates of the costs for the different strategies. In addition, we have included analysis on benefit of reduction of complication by mumps and rubella.

Methods

We evaluated four different strategies: strategy 1, keep-up program with a second dose measles-mumps-rubella (MMR) vaccine at 4–6 years without catch-up campaign; strategy 2, additional catch-up campaign with measles (M) vaccine; strategy 3, catch-up campaign with measles-rubella (MR) vaccine; and strategy 4, catch-up campaign with MMR vaccine. The cost of vaccination included cost for vaccines, vaccination practices and other administrative expenses. The direct benefit of estimated using data from National Health Insurance Company, a government-operated system that reimburses all medical costs spent on designated illness in Korea.

Results

With the routine one-dose MMR vaccination program, we estimated a baseline of 178,560 measles cases over the 20 years; when the catch-up campaign with M, MR or MMR vaccines was conducted, we estimated the measles cases would decrease to 5936 cases. Among all strategies, the two-dose MMR keep-up program with MR catch-up campaign showed the highest benefit-cost ratio of 1.27 with a net benefit of 51.6 billion KRW.

Conclusion

Across different vaccination strategies, our finding suggest that MR catch-up campaign in conjunction with two-dose MMR keep-up program was the most appropriate option in terms of economic costs and public health effects associated with measles elimination strategy in Korea.     

Vaccination willingness,vaccine hesitancy,and estimated coverage at the first round of COVID-19 vaccination in China: A national cross-sectional study

BackgroundVaccination against coronavirus disease 2019 (COVID-19) has become an important public health solution. To date, there has been a lack of data on COVID-19 vaccination willingness, vaccine hesitancy, and vaccination coverage in China since the vaccine has become available.MethodsWe designed and implemented a cross-sectional, population-based online survey to evaluate the willingness, hesitancy, and coverage of the COVID-19 vaccine among the Chinese population. 8742 valid samples were recruited and classified as the vaccine-priority group (n = 3902; 44.6%) and the non-priority group (n = 4840; 55.4%).ResultsThe proportion of people’s trust in the vaccine, delivery system, and government were 69.0%, 78.0% and 81.3%, respectively. 67.1% of the participants were reportedly willing to accept the COVID-19 vaccination, while 9.0% refused it. 834 (35.5%) reported vaccine hesitancy, including acceptors with doubts (48.8%), refusers (39.4%), and delayers (11.8%). The current coverage was 34.4%, far from reaching the requirements of herd immunity. The predicted rate of COVID-19 vaccination was 64.9%, 68.9% and 81.1% based on the rates of vaccine hesitancy, willingness, and refusal, respectively.ConclusionsThe COVID-19 vaccine rate is far from reaching the requirements of herd immunity, which will require more flexible and comprehensive efforts to improve the population’s confidence and willingness to vaccinate. It should be highlighted that vaccination alone is insufficient to stop the pandemic; further efforts are needed not only to increase vaccination coverage but also to maintain non-specific prevention strategies.     

Impact of a regional Hib vaccination programme in Italy.

In the Veneto region of Italy, a coverage of 26% for Haemophilus influenzae type b (Hib) primary vaccination in 1-year-old children plus a 31-53% catch-up coverage in children 1-4 years of age resulted in a 91% reduction of Hib invasive disease in children <5 years of age. These data suggest that vaccination of older children can contribute substantially to herd immunity, even in settings where primary vaccination is low. Since a single Hib vaccine dose is efficacious in preventing Hib invasive disease in children over 1 year of age, and the costs of vaccination are reduced, catch-up should always be considered when introducing Hib vaccine in routine immunization programmes.     

腾冲县扩大国家免疫规划疫苗接种率调查分析

目的了解腾冲县扩大国家免疫规划（National Immunization Program,NIP）疫苗的接种现状,分析存在问题,促进免疫规划工作的可持续发展。方法采用容量比例概率抽样方法抽取30个村,每个村随机调查1~2岁儿童14人,共调查420名儿童NIP疫苗的基础免疫（初种）及加强免疫（复种）情况。结果建预防接种卡率100%,建预防接种证率100%,预防接种卡、证符合率68.57%。调查儿童卡介苗、口服脊髓灰质炎减毒活疫苗、白喉-破伤风-百日咳联合疫苗（Diphtheria,Tetanus and Pertussis Combined Vaccine;DTP）、首剂含麻疹成分疫苗（First Dose Measles-containing Vaccine,MCV1）、乙型肝炎疫苗（以上五种NIP疫苗简称＂五苗＂）基础免疫（初种）全程接种率为98.57%,合格接种率为82.38%;加强免疫（复种）第4剂（Fourth Dose）DTP（DTP4）、第2剂（Second Dose）MCV（MCV2）免疫接种率分别为91.09%、92.25%,合格接种率分别为86.82%、89.92%。NIP新增疫苗A群脑膜炎球菌多糖疫苗（Group A Meningococcal Polysaccharide Vaccine,MPV-A）、首剂流行性乙型脑炎减毒活疫苗（First Dose Japanese Encephalitis Attenuated Live Vaccine,JEV-L1）、甲型肝炎减毒活疫苗基础免疫（初种）接种率分别为92.38%、97.38%、92.98%,合格接种率为84.52%、83.10%、80.95%;第二剂（Second Dose）JEV-L（JEV-L2）接种率为92.25%,合格接种率为79.53%。不合格接种的前三位原因是漏种/未完成全程接种、提前接种、超期接种;主要不合格接种疫苗为JEV-L、MPV-A、MCV、DTP。结论腾冲县NIP非新增疫苗基础免疫（初种）接种率﹥99%,加强免疫（复种）及NIP新增疫苗接种率﹥90%,但合格接种率相对较低,要在保持和提高接种率的同时,提高合格、有效接种是核心。     

Measles immunity over two decades in two large Italian Regions: How far is the elimination goal?

In Italy, the inclusion of measles vaccine in children immunization schedule and the promotion of national mass vaccination campaigns increased measles vaccination coverage. However, measles outbreaks continue to occur increasingly involving adolescents and adults. The aim of this study was to evaluate the prevalence to measles antibody in a sample of Italian population between 1993 and 2018.Human serum samples from subjects aged 3–40 years were collected between 1993 and 2018 and tested for measles IgG antibodies by commercial ELISA.During the study period, the 3–10-year-old age group showed the most important change, with a significant increase in 2003–2007 in both seroprevalence and IgG levels, followed by a slow decrease. The 11–18-year-old age group showed relatively stable seroprevalence rates and IgG levels over the years. The 19–30-year-old group showed stable seroprevalence rates, albeit with a decrease in IgG levels. After a significant increase in 1999–2002, the 31–40-year-old age group had high seroprevalence rates and IgG levels.Despite efforts at national level for implementing measles vaccination, a large proportion of the population is still susceptible to measles. Even if vaccination coverage increases enough to achieve the level of immunization required for herd immunity in new birth cohorts, outbreaks will continue to occur if there are immunity gaps in older age groups. Establishing policies for measles vaccination targeting adult population is needed to close immunity gaps and reach the elimination goal.     

Utilization and impact of European immunization week to increase measles,mumps, rubella vaccine uptake in Austria in 2016

This paper describes engagement in European Immunization Week (EIW) in Tyrol, Austria in April 2016 and an assessment of its possible impact on demand for measles, mumps, rubella vaccination (MMR).It further describes the output of a knowledge, attitudes and practice (KAP) survey conducted during EIW, showing that 93% (188/202) of respondents were in favor of vaccination in general and 90% (192/214) perceived MMR vaccination to be important. MMR vaccination was perceived as important by more participants than other vaccinations.The number of MMR doses administered by public health services in the province of Tyrol during EIW was greater than in the previous week, and EIW activities thus potentially resulted in increased MMR vaccine uptake in Tyrol during the observed period. The annual EIW campaign provides important opportunities to address vaccine hesitancy by raising awareness about immunization, to identify barriers to immunization and test possible solutions.     

Evaluation of a measles vaccine campaign in Ethiopia using oral-fluid antibody surveys

We undertook a study to demonstrate the potential contribution of oral-fluid (OF) antibody prevalence surveys in evaluating measles vaccine campaigns. In Asela town, southern Ethiopia, oral fluids were collected from 1928 children aged 9 months to 5 years attending for campaign immunization in December 1999 and 6 months later, from 745 individuals aged 9 months to 19 years, in the same location. Measles antibody status was determined by microimmune measles specific IgG enzyme immunoassay (EIA). Antibody prevalence was estimated at 48% in children attending for vaccination (pre-campaign), and 85% post-campaign in the comparable age group. The estimated reduction in the susceptible proportion was 75%. In older children the proportion antibody negative post-campaign was 28% in 7-9 year olds, and 13% in 10-14 year olds levels of susceptibility which raise concern over continued measles transmission. This is the first evaluation of a measles vaccine campaign based on oral-fluid seroprevalence surveys and it demonstrates the merit of oral-fluid surveys in informing health authorities about vaccination strategy refinement.