Measles-containing Vaccine Research Articles

Estimating the optimal age for infant measles vaccination.

The persistence of measles in many countries demonstrates large immunity gaps, resulting from incomplete or ineffective immunization with measles-containing vaccines (MCVs). MCV impact is determined, in part, by vaccination age. Infants who receive dose 1 (MCV1) at older ages have a reduced risk of vaccine failure, but also an increased risk of contracting infection before vaccination. Here, we designed a new method-based on a mathematical transmission model incorporating realistic vaccination delays and age variations in MCV1 effectiveness-to capture the MCV1 age risk trade-off and estimate the optimal age for recommending MCV1. We applied this method to a range of synthetic populations representing lower- and higher-income populations. We predict a large heterogeneity in the optimal MCV1 ages (range: 6-20 months), contrasting the homogeneity of observed recommendations worldwide. Furthermore, we show that the optimal age depends on the local epidemiology of measles, with a lower optimal age predicted in populations having lower vaccination coverage or suffering higher transmission. Overall, our results suggest the scope for public health authorities to tailor the recommended schedule for better measles control.

Progress Toward Measles Elimination - Worldwide, 2000-2023.

Measles vaccination effectively prevents measles, a highly contagious disease that can cause severe complications and death and requires high population immunity to interrupt transmission. This report describes measles elimination progress during 2000-2023. During 2000-2023, an estimated 60.3 million measles deaths were averted by vaccination. However, despite commitment from all six World Health Organization regions to eliminate measles, no region has successfully achieved and maintained measles elimination as of the end of 2023. During the COVID-19 pandemic, estimated global coverage with the first dose of measles-containing vaccine (MCV1) declined to 81%, the lowest level since 2008. MCV1 coverage improved to 83% in 2022 but was unchanged in 2023. From 2022 to 2023, estimated measles cases increased 20% worldwide, from 8,645,000 to 10,341,000; the number of countries experiencing large or disruptive outbreaks increased from 36 to 57. Estimated measles deaths decreased 8%, from 116,800 in 2022 to 107,500 in 2023, primarily because an increased number of cases occurred in countries with lower risk for death. The stagnation in MCV1 coverage means millions of children remain unprotected, leading to increases in cases and outbreaks. Coverage with measles-containing vaccine (MCV) is lower, and measles incidence is higher, in low-income countries and countries experiencing fragile, conflict-affected, and vulnerable settings, which exacerbate inequities. Urgent and targeted efforts are needed to ensure that all children receive 2 MCV doses and that surveillance is strengthened to hasten progress toward measles elimination.

Measles–Rubella Microarray Patches Phase III Clinical Trial Framework: Proposal and Considerations

Background: The Measles–Rubella Microarray Patch (MR-MAP) is an important technology that is expected to reduce coverage and equity gaps for measles-containing vaccines (MCVs), reach zero-dose children, and contribute to elimination of measles and rubella. MR-MAPs are anticipated to be easier to deploy programmatically and could be delivered by lesser-trained health workers, thereby increasing immunization coverage. The most advanced MR-MAP has reached clinical proof-of-concept through a Phase I/II trial in the target population of infants and young children. The World Health Organization (WHO) and partners have developed the Phase III clinical trial framework for MR-MAPs presented in this article. Objectives and Methods: The purpose of such framework is to inform the considerations, design and approach for the pivotal clinical trial design, while considering the anticipated data requirements to inform regulatory approval, WHO prequalification, and policy decision. Results: The proposed Phase III trial would compare the immunogenicity and safety of an MR-MAP with MR vaccine delivered subcutaneously in 9- to 10-month-old infants. An analysis of non-inferiority (NI) of immunogenicity would occur six weeks after the first dose. Should regulatory agencies or policy makers require, a proportion of infants could receive a second dose of either the same or alternate MR vaccine presentation six months after the first dose, with those children returning six weeks after the second dose for a descriptive assessment of immunogenicity, and then followed up six months after the second dose for evaluation of safety and immunogenicity. It is anticipated that this proposed pivotal Phase III trial framework would generate the required clinical data for regulatory licensure and WHO prequalification (PQ) of MR-MAPs. However, the trial design would need to be reviewed and confirmed by a national regulatory authority (NRA) that will assess the product for regulatory licensure and the WHO PQ team. Additional research will likely be required to generate data on concomitant vaccine delivery, the safety and immunogenicity of MR-MAPs in other age groups such as children 1–5 years and infants younger than 9 months of age, and the impact of MR-MAPs on coverage and equity. Such studies could be conducted during or after clinical MR-MAP development.

Coverage of Second Dose of Measles-Containing Vaccine (MCV-2) and Japanese Encephalitis Vaccine (JE-2) and Its Predictors Among Children 2–5 Years Old in the Ormanjhi Block of Ranchi, Jharkhand, India: A Mixed Method Study

Coverage of Second Dose of Measles-Containing Vaccine (MCV-2) and Japanese Encephalitis Vaccine (JE-2) and Its Predictors Among Children 2–5 Years Old in the Ormanjhi Block of Ranchi, Jharkhand, India: A Mixed Method Study

Routine Vaccination Coverage - Worldwide, 2023.

In 2020, the World Health Assembly endorsed the Immunization Agenda 2030 (IA2030), a 10-year strategy to reduce vaccine-preventable disease (VPD)-associated morbidity and mortality. IA2030 goals include improving equitable vaccination coverage, halving the number of unimmunized (zero-dose) children, and increasing the introduction of new and underutilized vaccines. The COVID-19 pandemic disrupted health systems worldwide, hindering years of childhood vaccination achievements and putting global public health goals at risk. This report presents trends in World Health Organization (WHO) and UNICEF routine vaccination coverage estimates through 2023 across the 194 WHO member countries. During 2022-2023, global coverage with the first and third doses of diphtheria-tetanus-pertussis-containing vaccine (DTPcv) (89% and 84%, respectively) and the first dose of measles-containing vaccine (83%) stagnated and remained lower than prepandemic levels. The 31 WHO member countries with fragile, conflict-affected, and vulnerable (FCV) settings include approximately one half of the world's 14.5 million children who did not receive the first DTPcv dose. The introduction of new and underutilized vaccines, such as a second MCV dose in the African Region, has improved countries' overall protection against VPDs. Accelerating country-specific routine immunization and catch-up vaccination programs to reach unvaccinated and incompletely vaccinated children, especially those living in FCV settings, is critical to reducing morbidity and mortality associated with VPDs.

Preparing for outbreaks of vaccine preventable diseases: why are prisons invisible?

Abstract From 1 March 2023 to 29 February 2024, 30 EU/EEA Member States reported a total of 5 770 cases of measles, 4 864 (84.3%) of which were laboratory-confirmed. Th7e highest number of cases were reported by Romania- at the time of writing, 11,397 confirmed cases, including 12 deaths from 1 January 2023 to 7 April 2024. Measles is a highly infectious disease. The best mitigation is vaccination which is highly effective. Outbreaks in many countries have been driven by decreases in vaccine coverage with a two-dose measles-containing vaccine (MCV), especially evident since the COVID-19 pandemic. In many countries, vulnerable migrant populations, ethnic groups and communities experiencing social deprivation have been over-represented in cases and under-covered by vaccine programmes. We know that prisons contain such populations. Historic seroprevalence studies of prison populations, which themselves are scant, show that prison populations are under-vaccinated. Prisons are a setting that can cause disease amplification. Given these facts, it is perhaps surprising that many countries in Europe cannot provide specific surveillance data on either cases in prisons or vaccine coverage specifically in prison populations. Further, that prisons are not often cited as specific settings for vaccine catch-up programmes in national or regional programmes. This is despite evidence of measles cases and outbreaks historically and currently in several European countries. In the presentation we will ask why this ‘blind spot’ in national and international disease surveillance continues and what Member States could and should do to prevent the risk of mass outbreaks of measles in prisons, causing pressures on justice and health systems and risking wider community outbreaks. Finally, we will reflect on how this experience should alert us to the risk of other infectious diseases going undetected, unprevented, and under-studies in prisons, threatening our collective health security.

Trends of Diphtheria–Tetanus–Pertussis and Measles Vaccine Coverage Preceding and during the COVID-19 Pandemic: An Analysis of the WHO European Region from 2000 to 2022

Available data highlights the significant impact of the COVID-19 pandemic on global vaccination trends. Despite this, comprehensive evaluations of these changes at the European level are still scarce. This study examines coverage for diphtheria, tetanus, and pertussis (DTP) and measles-containing vaccines (MCV) in the WHO European Region from 2000 to 2022. Vaccination coverage data, defined as the percentage of surviving infants who received the first and third doses of DTP (DTP1 and DTP3) and the first and second doses of MCV (MCV1 and MCV2), were extracted from UNICEF databases. Joinpoint regression analysis was employed to identify joinpoints in the time series and to estimate Annual Percent Changes (APCs) and Average Annual Percent Changes (AAPCs) over predefined timeframes. The coverages for DTP1 and MCV1 exhibit a similar trend, overall characterized by four joinpoints, one of which is in 2019. In contrast, the coverage for DTP3 does not show a significant temporal trend and lacks joinpoints, while the vaccination coverage for MCV2 shows a steadily increasing trend, with three identified joinpoints. A comparative analysis with the pre-pandemic period reveals a significant increase in the number of countries characterized by a decreasing trend during the pandemic period for all considered vaccination coverages, as indicated by the negative AAPC values. These results highlight the effect of the pandemic on childhood vaccination coverage. Compared to a mere descriptive analysis, the temporal analysis of trends using joinpoint regression provides significant opportunities to identify variations in vaccination coverages and pinpoint areas for intervention in future vaccination strategies.

Progress with the Second Dose Measles Vaccine Introduction and Coverage in the WHO African Region.

To achieve global and regional measles elimination objectives, the World Health Organization (WHO) recommends coverage of 95% or higher with two doses of measles-containing vaccine. A second dose of measles-containing vaccine (MCV) is typically administered in the second year of life after 12 months of age. We reviewed WHO-UNICEF estimates of national coverage (WUENIC) for the first and second doses of MCV (MCV1 and MCV2, respectively) and calculated drop-out rates between MCV1 and MCV2 for countries in the WHO African Region. From 2013 to 2023, estimated regional MCV2 coverage increased from 7% to 49%, and at the end of 2023, 43 (91%) countries had introduced MCV2 into their routine immunization programs. Countries with more antigens provided in the second year of life had higher mean and median MCV2 coverage levels, and lower drop-out rates between MCV1 and MCV2, as compared to countries providing only MCV2. Despite substantial progress, MCV2 coverage remains below the required levels to achieve and sustain elimination, and many countries have high drop-out rates between MCV1 and MCV2 coverage, indicating challenges in reaching children over 12 months of age. Increasing coverage of MCV2 and other vaccines in the second year of life is essential to achieving higher and equitable routine immunization coverage. This will require continued efforts to understand and mitigate barriers to reaching children after 12 months of age and accelerated implementation of available tools.

Impact of the COVID-19 Pandemic on Measles Vaccination Coverage and Estimated Catch-up Efforts for Serbia.

Measles is highly infectious, requiring ≥95% vaccine coverage rate (VCR) to prevent outbreaks. This study aimed to understand the impact of the COVID-19 pandemic on routine measles-containing vaccine (MCV) VCRs in Serbia and estimate national and regional catch-up vaccination required to prevent outbreaks. A multiplier model was used to calculate annual MCV dose 1 (MCV1) and MCV dose 2 (MCV2) VCRs for children 1-6 and 6-12 years of age, respectively, for 2011-2022. Postpandemic (2023-2024) VCRs were modeled. The numbers of administered doses were compared to prepandemic and postpandemic, and monthly catch-up rates were calculated for 12-, 18- and 24-month campaigns. Between prepandemic and pandemic periods, national MCV1 VCR decreased from 88% to 81%, while MCV2 VCR decreased from 92% to 89%, corresponding to 20,856 missed MCV1 and 8760 missed MCV2 doses. Assuming national VCRs returned to prepandemic levels post-2022, 18% of children 1-6 years of age and 11% of children 6-12 years of age would have missed their MCV1 and MCV2 doses, respectively, by 2024. To catch up missed doses under this scenario, most regions would require monthly catch-up rates of 25%, 16% or 12% for MCV1 and 14%, 9% or 7% for MCV2, considering 12-, 18- or 24-month campaigns, respectively. The pandemic negatively impacted MCV VCRs in Serbia, leaving a sizeable proportion of children with missed doses. Significant catch-up efforts are required to recover VCRs to prepandemic levels and avoid future measles outbreaks, with increased monthly administration rates versus those in prepandemic periods.

The Effects of Vaccination Status and Age on Clinical Characteristics and Severity of Measles Cases in the United States in the Post-Elimination Era, 2001-2022.

Despite high vaccine-effectiveness, wild-type measles can occur in previously vaccinated persons. We compared the clinical presentation and disease severity of measles by vaccination status and age in the post-elimination era in the United States. We included U.S. measles cases reported from 2001-2022. Breakthrough measles was defined as cases with ≥1 documented dose of measles-containing vaccine, classic measles as the presence of rash, fever, and ≥1 symptoms (cough, coryza, or conjunctivitis), and severe disease as the presence of pneumonia, encephalitis, hospitalization, or death. Vaccinated cases with low and high avidity IgG were classified as primary (PVF) and secondary (SVF) vaccine failures, respectively. Among 4,056 confirmed measles cases, 2,799 (69%) were unvaccinated, 475 (12%) were breakthrough infections, and 782 (19%) had unknown vaccination; 1,526 (38%), 1,174 (29%), and 1,355 (33%) were aged <5, 5-19, and ≥20 years, respectively. We observed a general decline in classic presentation and severe disease with an increase in the number of doses, and less complications among children aged 5-19 years compared to other age-groups. Among 93 breakthrough cases with avidity results, 11 (12%) and 76 (82%) were classified as PVF and SVF, respectively, with a higher proportion of PVFs having a classic measles presentation and severe disease than SVFs. Breakthrough measles cases tended to have milder disease with less complications. A small proportion of breakthrough infections were due to PVF than SVF. It is critical to maintain high MMR vaccination coverage in the United States to prevent serious measles illnesses.

Vaccine-associated measles in an immunocompromised host: Hospital infection prevention and control and public health response

Introduction: Vaccine-associated measles is generally not considered to be transmissible, as opposed to wild-type measles, which is one of the most highly contagious diseases. Data on contact and exposure management of vaccine-associated measles is limited, with varied approaches to such cases described in the literature. Methods: We report the case of a 2-year-old immunosuppressed child who developed a febrile exanthem with mild conjunctivitis 18 days after receiving the measles-mumps-rubella-varicella vaccine. Results: Given the patient's recent measles-containing vaccination while on immunosuppressive medications, consistent clinical findings and the lack of epidemiological risk factors for wild-type infection, the decision was made to treat this as a presumptive case of vaccine-associated measles virus prior to return of confirmatory genotyping results. After consultation with public health experts, contact tracing was not considered necessary. No secondary measles cases were identified, despite a large exposure potential due to lack of consistent airborne precautions during hospital admission. Discussion: This case highlights the lack of transmissibility of vaccine-associated measles in immunocompromised hosts, adding to the scant body of literature on this topic, with the potential to inform hospital infection prevention and control as well as public health management in similar situations.

Onward transmission of measles virus among vaccinated cases in a large community outbreak in Auckland, New Zealand, 2019

Background: Isolation of cases and quarantining of non-immune contacts are the mainstay of measles outbreak management in elimination settings. Serology testing of exposed contacts may not be feasible in large outbreaks; therefore, vaccination history is used as a proxy for determining immunity to measles and thus prevention of onward virus transmission. This study sought to investigate the risk of measles virus transmission from individuals with a history of one or two doses of measles-containing vaccine (MCV). Methods: Retrospective analysis of data from measles cases reported to Auckland Regional Public Health Service during the 2019 Auckland region measles outbreak. Vaccination history was verified using patient records and the New Zealand National Immunisation Register. Onward transmission was determined through case interviews and assessment of exposed contacts. Results: 1451 measles cases were assessed as eligible for vaccination at the time of measles outbreak. Of these, 1015 (70.0%) were unvaccinated, 220 (15.2%) had unknown vaccination status, 139 (9.6%) had received only one dose of MCV and 77 (5.3%) had received two doses of the vaccine. Compared to unvaccinated cases, the odds of onward transmission were lower among those with one dose only (OR 0.41, 95% CI: 0.20–0.75) or two doses of MCV (OR 0.44, 95% CI: 0.17–0.95). Median time since vaccination was longer among those with onward transmission compared to those without onward transmission for one and two doses of the vaccine, suggesting a potential effect of waning immunity among this cohort. Conclusion: These findings support the hypothesis that measles cases with a history of prior vaccination are less likely to transmit the virus to others compared to unvaccinated cases. Such information can be used to support decisions around quarantine requirements for vaccinated contacts in future measles outbreaks.

Using Regular High-Quality Serosurveys to Identify and Close National Immunity Gaps-Measles and Rubella Elimination in Japan.

In Japan, periodic measles outbreaks occurred mainly among young children under the routine immunization program with one dose of the measles-containing vaccine (MCV). A second dose of MCV was introduced in 2006. During a nationwide measles resurgence in 2007-2008, the most affected age group was teenagers. The national serological surveillance for vaccine-preventable diseases made it clear that there was a measles immunity gap among teenagers who had not received a second dose of MCV. To fill this immunity gap, nationwide non-selective supplementary immunization activities (SIAs) were carried out as a five-year program from April 2008 to March 2013 by providing an opportunity to be vaccinated with the measles and rubella vaccine during the first year of junior high school (12-13 years old) and the last year of high school (17-18 years old). The SIA was conducted with the strong involvement of local governments in charge of vaccination delivery and collaboration between the health and education sectors. Japan was verified as achieving measles elimination in 2015 and this has been sustained to date. The challenge of rubella elimination following a similar strategy of a serological diagnosis of an immunity gap and targeted vaccination is also discussed.

Measles Population Immunity Profiles: Updated Methods and Tools.

Measles is a highly contagious disease and remains a major cause of child mortality worldwide. While measles vaccine is highly effective, high levels of population immunity are needed to prevent outbreaks. Simple but accurate tools are needed to estimate the profile of population measles immunity by age to identify and fill immunity gaps caused by low levels of vaccination coverage. The measles immunity profile estimates and visualizes the percentage of each birth cohort immune or susceptible to measles based on measles vaccination coverage. Several tools that employed this approach have been developed in the past, including informal unpublished versions. However, these tools used varying assumptions and produced inconsistent results. We updated the measles population immunity profile methodology to standardize and better document the assumptions and methods; provide timely estimates of measles population immunity; and facilitate prompt actions to close immunity gaps and prevent outbreaks. We recommend assuming that the second dose of the measles-containing vaccine (MCV2) and doses given during supplementary immunization activities (SIAs) first reach children who have been previously vaccinated against measles, so that previously unvaccinated children are reached only when the coverage of MCV2 or SIA is higher than the coverage achieved by all previous measles vaccination opportunities. This updated method provides a conservative estimate of immunization program impact to assess measles outbreak risk and to facilitate early planning of timely preventive SIAs to close population immunity gaps.

Mapping the Implementation Determinants of Second Dose Measles Vaccination in the World Health Organization African Region: A Rapid Review.

The second dose of measles-containing vaccines (MCV2) has significant programmatic relevance in the current immunisation landscape because it serves as both an opportunity to reduce measles immunity gaps and strengthen second year of life vaccination platforms. However, MCV2 coverage remains suboptimal across countries in the World Health Organization (WHO) African Region and this puts a significant number of children at risk of morbidity and mortality from measles despite the availability of an effective vaccine. There is an urgent need to strengthen the implementation of MCV2 but this requires a thorough and systematic understanding of contextual factors that influence it. The literature that describes the determinants of implementation of MCV2 in a manner that adequately accounts for the complexity of the implementation context is scarce. Therefore, the purpose of this rapid review was to explore the implementation determinants of MCV2 in the WHO African Region using systems thinking. Literature search in two databases (PubMed and Google Scholar) were conducted. After screening, a total of 17 eligible articles were included in the study. Thematic analysis of extracted data was performed to identify the implementation determinants, after which they were mapped using the Consolidated Framework for Implementation Research (CFIR). A causal loop diagram (CLD) was used to illustrate the linkages between identified determinants. We found 44 implementation determinants across the five CFIR domains, i.e., innovation, outer setting, inner setting, individual, and implementation process. The majority of identified determinants are within the individual domain followed by the inner setting domain. The CLD showed that multiple contingent connections and feedback relationships exist between the identified implementation determinants within and across CFIR domains. The linkages between the implementation determinants revealed three balancing and reinforcing loops each. The findings suggest that implementation determinants of second-dose measles vaccination in the WHO African Region are complex, with multiple interconnections and interdependencies, and this insight should guide subsequent policies. There is an urgent need for further implementation research with embedded CLD in specific settings to inform the design of tailored systemic strategies to improve the implementation effectiveness of MCV2.

Measles second dose vaccine uptake and associated factors among under-five children in Jigjiga City, Somali Region, Eastern Ethiopia: a community-based cross-sectional study.

Measles is one of the leading causes of under-five mortality and morbidity worldwide. Although the routine service for the second dose of the measles-containing vaccine (MCV2) was introduced in Ethiopia recently, there is a paucity of evidence regarding its coverage and the factors that hinder its uptake at both the local and national levels. Thus, this study aimed to assess the uptake of MCV2 and its associated factors among children aged between 15 and 36 months old in Jigjiga City, Somali Region, Ethiopia. A community-based cross-sectional study was conducted among 429 children aged between 15 and 36 months old with their mothers/caregivers in Jigjiga City from April 1 to May 1, 2023. A multistage sampling technique was used and data were collected by using structured interviewer-administered questionnaires. The collected data were entered into Epi-data version 3.2 and analyzed in a statistical package for the social sciences (SPSS) version 26. Bivariate and multivariable logistic regression analyses were performed to identify factors associated with the uptake of the measles second dose vaccine. An adjusted odds ratio with 95% CI were reported and statistical significance was declared at p < 0.05. The coverage of MCV2 among children aged between 15 and 36 months was 21.4% (95% CI: 17.7, 25.2). The educational status of the mother (AOR = 3.154; 95% CI: 1.68, 5.93), place of delivery (AOR = 1.90; 95% CI: 1.08, 3.25), postnatal care visits of the mother (AOR = 2.40; 95% CI: 1.37, 4.22), time taken to reach a health facility (AOR = 2.67; 95% CI: 1.28, 5.57), and knowledge about child vaccination (AOR = 2.43; 95% CI: 1.45, 4.08) were factors significantly associated with the uptake of the measles second dose vaccine. The coverage of MCV2 in the study area was low compared to the national immunization targets. Educational status of the mother/caregivers, place of delivery, postnatal care visits of the mother, time to reach a health facility, and knowledge about vaccination of children were significantly associated with measles second dose vaccination. The focus should be given to improving the awareness of mothers on the importance of child vaccination to improve the uptake of measles second dose vaccine and reduce the burden of measles in the region.

Modeling the Cost of Vaccinating a Measles Zero-Dose Child in Zambia Using Three Vaccination Strategies.

Countries with moderate to high measles-containing vaccine coverage face challenges in reaching the remaining measles zero-dose children. There is growing interest in targeted vaccination activities to reach these children. We developed a framework for prioritizing districts for targeted measles and rubella supplementary immunization activities (SIAs) for Zambia in 2020, incorporating the use of the WHO's Measles Risk Assessment Tool (MRAT) and serosurveys. This framework was used to build a model comparing the cost of vaccinating one zero-dose child under three vaccination scenarios: standard nationwide SIA, targeted subnational SIA informed by MRAT, and targeted subnational SIA informed by both MRAT and measles seroprevalence data. In the last scenario, measles seroprevalence data are acquired via either a community-based serosurvey, residual blood samples from health facilities, or community-based IgG point-of-contact rapid diagnostic testing. The deterministic model found that the standard nationwide SIA is the least cost-efficient strategy at 13.75 USD per zero-dose child vaccinated. Targeted SIA informed by MRAT was the most cost-efficient at 7.63 USD per zero-dose child, assuming that routine immunization is just as effective as subnational SIA in reaching zero-dose children. Under similar conditions, a targeted subnational SIA informed by both MRAT and seroprevalence data resulted in 8.17-8.35 USD per zero-dose child vaccinated, suggesting that use of seroprevalence to inform SIA planning may not be as cost prohibitive as previously thought. Further refinement to the decision framework incorporating additional data may yield strategies to better target the zero-dose population in a financially feasible manner.

Measles outbreak in 2019: a warning for the post-COVID-19 pandemic period.

Introduction. At the end of 2019 and the year before, there was a significant spread of measles in the World Health Organization (WHO) European Region.Gap statement. Among the countries that reported, a measles outbreak was Bosnia and Herzegovina (BiH).Aim. To describe the measles outbreak in BiH (an entity of the Federation of BiH, FBiH) in 2019.Methodology. Confirmatory IgM serology, measles nucleic acid detection by real-time RT-PCR and virus genotyping were done in the WHO-accredited laboratory for measles and rubella at the Clinical Center of the University of Sarajevo, Unit for Clinical Microbiology. Genotype was determined in all measles-RNA-positive cases by sequence analysis of the 450 nt fragment coding the C-terminal of measles virus nucleoprotein (N).Results. From 1 January to 31 December 2019, 1332 measles cases were reported, with the peak observed in April 2019 (413/1332, 31.01 %). Sarajevo Canton had the highest incidence, number of cases and percentage (206.4; 868/1332; 65.17 %) of measles cases. Around four-fifths of infected persons were unvaccinated (1086/1332, 81.53 %), while 4.58 % of the patients (61/1332) were immunized with one dose of measles-containing vaccine. The highest proportion of cases was found in children 0-6 years of age (738/1332, 55.41 %). Measles IgM positivity was determined in 75.88 % (346/456), while virus RNA was detected in 82.46 % (47/57) of the swab samples. All measles virus sequences belonged to genotype B3. SNP (position 216: C=>T) was detected in 1 of the 40 sequences obtained during this outbreak.Conclusion. Due to suboptimal immunization coverage, BiH belongs to countries at a high risk for measles outbreaks. Post-COVID-19 (coronavirus disease 2019) pandemic, targeted and tailored strategies are required to ensure routine vaccination demand and acceptance and broad partner and stakeholder group participation.

Qualitative Insights on Barriers to Receiving a Second Dose of Measles-Containing Vaccine (MCV2), Oromia Region of Ethiopia.

Introduction: Ethiopia introduced a second dose of measles-containing vaccine (MCV2) in 2019 to provide further protection against measles and further progress toward elimination. However, the sub-optimal coverage of both MCV1 and MCV2 suggest challenges with vaccine uptake. In this qualitative study, we explored barriers to the uptake of MCV2 among caregivers, community leaders, and healthcare workers (HCWs). Method: A qualitative study was conducted between mid-April and mid-May 2021. We selected ten woredas (districts) in the Oromia Region, Ethiopia, stratified by settlement type (urban/rural), MCV1 coverage (high ≥ 80%; low < 80%), and history of measles outbreaks between June 2019 and June 2020. Experiences surrounding barriers to MCV2 uptake were discussed via focus group discussions (FGDs) and in-depth interviews (IDIs) with caregivers of children 12-23 and 24-36 months and key informant interviews (KIIs) with HCWs who administer vaccines and with community leaders. Participants were recruited via snowball sampling. Recorded data were transcribed, translated to English, and analyzed using ATLAS.ti v.09. Results: Forty FGDs and 60 IDIs with caregivers, 60 IDIs with HCWs, and 30 KIIs with community leaders were conducted. Barriers among caregivers included lack of knowledge and awareness about MCV2 and the vaccination schedule, competing priorities, long wait times at health facilities, vaccine unavailability, negative interactions with HCWs, and transportation challenges. At the community level, trusted leaders felt they lacked adequate knowledge about MCV2 to address caretakers' questions and community misconceptions. HCWs felt additional training on MCV2 would prepare them to better respond to caretakers' concerns. Health system barriers identified included the lack of human, material, and financial resources to deliver vaccines and provide immunization outreach services, which caretakers reported as their preferred way of accessing immunization. Conclusions: Barriers to MCV2 uptake occur at multiple levels of immunization service delivery. Strategies to address these barriers include tools to help caretakers track appointments, enhanced community engagement, HCW training to improve provider-client interactions and MCV2 knowledge, and efforts to manage HCW workload.

Accelerating Global Measles and Rubella Eradication-Saving Millions of Lives, Preventing Disability, and Averting the Next Pandemic.

No vaccine has been more effective in reducing disease burden, especially in preventing child deaths, than measles-containing vaccine. The return on investment makes measles-containing vaccine one of the most cost-effective public health measures available. Exhaustive reviews of biological, technical, economic and programmatic evidence have concluded that measles can and should be eradicated, and by including rubella antigen in measles-containing vaccine, congenital rubella syndrome will also be eradicated. All World Health Organisation Regions have pledged to achieve measles elimination. Unfortunately, not all countries and global partners have demonstrated an appropriate commitment to these laudable public health goals, and the negative impact of the COVID-19 pandemic on coverage rates has been profound. Unsurprisingly, large disruptive outbreaks are already occurring in many countries with a global epidemic curve ominously similar to that of 2018/2019 emerging. The Immunization Agenda 2030 will fail dismally unless measles and rubella eradication efforts are accelerated. Over half of all member states have been verified to have eliminated rubella and endemic rubella transmission has not been re-established in any country to date. In 2023, 84 countries and areas were verified to have sustained elimination of measles. However, without a global target, this success will be difficult to sustain. Now is the time for a global eradication goal and commitment by the World Health Assembly. Having a galvanising goal, with a shared call for action, will demand adequate resourcing from every country government and global partners. Greater coordination across countries and regions will be necessary. Measles, rubella and congenital rubella syndrome eradication should not remain just a technically feasible possibility but rather be completed to ensure that future generations of children do not live under the shadow of preventable childhood death and lifelong disability.