Measles remains a global health threat, and rising vaccine hesitancy in Malaysia underscores the need for locally tailored communication strategies to strengthen public trust and vaccination. This current research developed and validated the Parental Health Education (PaHE)-Measles toolkit, grounded in the Health Belief Model, to support parental confidence and the uptake of measles, mumps, and rubella (MMR) vaccination in Malaysia through a four-stage process: information gathering, preliminary adaptation design, preliminary adaptation testing, and adaptation refinement. Five multidisciplinary experts validated its content both in Malay and English, and 10 health care providers confirmed overall quality. The acceptability was assessed among 30 end-users. The PaHE-Measles achieved a Content Validity Index (CVI) score of 1.0 from expert reviewers, whereas health care providers rated its understandability and actionability more than 80%. End-users reported an average score of over 9.0. In conclusion, PaHE-Measles is a valid and ready toolkit for educating parents, countering misinformation, and strengthening vaccine confidence.

Hybrid microneedle patch for administration of measles and rubella vaccine with an on-patient medical record.

Intention to vaccinate children against measles: findings from a national survey in the United States.

Background:Cutaneous warts are exophytic, benign proliferative lesions caused by human papillomavirus infection of basal keratinocytes. Many intralesional immunomodulatory agents are used by dermatologists these days including Bacillus Calmette–Guerin vaccine, measles–mumps–rubella vaccine, purified protein derivative (PPD), Candida extract, vitamin D3, interferon alpha, zinc sulphate, and hepatitis B vaccine. Intralesional acyclovir is considered a novel intralesional therapy for warts as it directly destroys the viral cells. The objectives of this study are to provide the latest comparison among different intralesional therapies and to specifically compare acyclovir with PPD.Methods:A comprehensive search strategy was implemented to identify relevant randomized controlled trials, and those with single-arm studies were excluded. After this, 5 studies were finally included in the review. Statistical analysis was done using a frequentist random-effects model. Dichotomous outcomes were analyzed using odds ratio and 95% confidence interval with statistical significance set as P-value < .05. All analyses were performed using R version 4.4.1.The study involved a total of 295 patients with sample size ranging from 30 being the least number of participants and 97 being the highest number of participants in a single study.Results:Use of saline had the highest probability of being the best treatment for achieving a complete response (probability to be the best 96%, P-score = .96) and partial response (98% probability, P-score = .98) when compared with other modalities. The forest plot shows no statistically significant differences among the treatment arms except for saline (P < .01) for no response as compared with PPD. Blister formation was found to be higher on the use of cryotherapy (P = .03) and Mycobacterium w vaccine (P = .02).Conclusion:This network’s meta-analysis concludes the superiority of intralesional saline in achieving response to treatment when compared with other modalities such as cryotherapy and vaccines. A higher risk of adverse events was noted on use of vaccines. Future research is needed to strengthen these findings.

How does misinformation contribute to socioeconomic disparities in childhood vaccine uptake? While prior research has extensively examined the determinants of vaccination at the population-level, less attention has been paid to the mechanisms generating disparities across socioeconomic status (SES) groups. A fundamental cause theory perspective suggests that vaccination disparities driven by misinformation are due to unequal access to resources that enable higher-SES parents to avoid the influence of such misinformation. By contrast, a neoliberal cultural frames of parenting perspective suggests that higher-SES parents, in trying to avoid risks for their child, would be more receptive to inaccurate claims that arise outside the mainstream medical and scientific community. We test hypotheses from these two perspectives using 22 birth cohorts of Danish national health registry data (1990-2011) analyzing uptake of children's first dose of the measles, mumps, and rubella vaccine (MMR1) by parental education level in the context of three major vaccine misinformation events: two promoting and one correcting misinformation. We find that educational disparities in MMR1 uptake emerged following a 1993 national radio broadcast that falsely linked the vaccine to autism and helped catalyze anti-vaccine activism in Denmark. Children of parents with the lowest education were most severely impacted, and these disparities persisted through the 1998 publication and 2010 retraction of Andrew Wakefield's widely publicized MMR vaccine and autism study. Together, these findings generally support fundamental cause theory-based explanations and demonstrate persisting and unequal harms of misinformation on child and community health.

Measles is a highly contagious vaccine-preventable viral disease. Successful vaccination programs resulted in limited measles transmission in the United States in 2000, but U.S. cases have been increasing since early 2025. On May 20, 2025, CDC notified the Colorado Department of Public Health and Environment of a measles case in an unvaccinated, non-Colorado resident who had arrived in Denver, Colorado, on an international flight and traveled through the Denver International Airport while infectious. The patient acquired measles in the United States before travelling internationally. Nine secondary measles cases and one tertiary case associated with this traveler were confirmed among Colorado residents; seven additional cases were reported by other jurisdictions. Four of the nine secondary Colorado cases occurred among persons who had received 2 doses of measles, mumps, and rubella vaccine before exposure. Two of these vaccinated persons received negative measles reverse transcription-polymerase chain reaction (RT-PCR) test results from nasopharyngeal swab specimens and positive results from urine specimens. A third patient, with unknown measles vaccination status, received a positive urine RT-PCR test result 24 days after rash onset. Three unvaccinated patients and one with unknown vaccination status were hospitalized, and all recovered. All patients reported having a rash, but vaccinated patients reported fewer and milder symptoms overall. This outbreak highlights the importance of staying up to date with recommended vaccinations, especially before traveling. Routinely collecting urine specimens for measles testing could improve identification of cases and increase detection sensitivity, especially among previously vaccinated persons.

Vaccines are our best defence against infectious diseases, yet uptake of childhood immunisation programmes has consistently declined in the UK, with growing concerns around socioeconomic inequalities. Liverpool, in particular, demonstrated some of the lowest uptake rates in England since 2019. In response, the Health Equity Liverpool Project (HELP) implemented a hyper-localised community-led initiative between September 2023 and June 2024 to tackle vaccine hesitancy. Activities included outreach events and school-based engagement across nine sites within Liverpool. Despite promising qualitative evidence, the intervention's impact on childhood vaccine uptake has not yet been quantified. We aim to evaluate the population level impact of the HELP intervention on the uptake of five childhood vaccines (first and second doses of the measles, mumps and rubella vaccine (MMR1, MMR2), 6-in-1 vaccine (diphtheria, tetanus, pertussis, polio, haemophilus influenzae type b and hepatitis B), pneumococcal conjugate vaccine booster dose (PCV) and rotavirus vaccine) using synthetic control methods. We will analyse publicly available quarterly vaccine uptake data (between April 2019 and March 2025) from the Cover of Vaccination Evaluated Rapidly programme for general practices (GPs) in England. The intervention group will be defined as practices located within a 1 km radius of the intervention sites. A synthetic control group will be constructed using non-intervention GPs matched on pre-intervention vaccine uptake, and linked demographic, socioeconomic and healthcare capacity covariates. Primary outcomes are the uptake of MMR1 and MMR2 vaccines. Secondary outcomes include the uptake of 6-in-1, PCV and rotavirus vaccines. Average treatment effects will be estimated as the post-intervention difference in uptake between intervention and synthetic control groups. Sensitivity analyses will examine spillover effects, alternative spatial definitions of exposure, the biasing effect of concurrent interventions and the feasibility of analysis at small area neighbourhood level. This study will be conducted as part of the ReCITE project, which has received ethical approval from the Liverpool School of Tropical Medicine Research Ethics Committee (Reference: 24-018) and is funded by the UK Arts and Humanities Research Council (Project Number: AH/Z505341/1). Findings will be shared with the project funder and submitted for publication in a peer-reviewed journal.

BackgroundRubella virus infection is a clinically mild illness, but it can have serious effects on pregnant women, such as miscarriage, stillbirth, or congenital rubella syndrome. However, rubella is neither a notifiable disease nor part of an immunization program in Ethiopia. A suspected case of rubella has been reported in Adigrat since November 26, 2023. The study aimed to investigate and control the suspected rubella outbreak.MethodsFollowing the descriptive study, a case-control study was conducted in Adigrat town from December 23, 2023, to March 30, 2024. Cases were people who presented with fever and maculopapular or laboratory-confirmed cases or epidemiologically linked with the confirmed person, and controls were neighbours to a case with no signs and symptoms of rubella. Cases were selected using simple random sampling, and controls were the two closest neighbours per case. Data was collected using a semi-structured questionnaire and analysed with SPSS version 27. Logistic regression was used to determine the association of illness with risk factors, and the results were tested using OR, a 95% confidence interval.ResultA total of 350 cases of rubella were identified with an attack rate of 3.16/1000. The attack rate was high in children aged five to nine years (11/1000) and in kebelle 04 (8/1000). Five out of seven samples were tested positive for rubella-specific IgM antibodies. Having contact in a school setting (AOR = 7.063: 95% CI = 3.269–15.256), having household contact (AOR = 6.551:95%CI = 2.534–16.941) and ≥ 5 family size (AOR = 2.312:95%CI = 1.090–4.907) were significantly associated with rubella.ConclusionThe overall attack rate of the rubella outbreak was high, with a predominance of children under fifteen. Large family size, and having contact with infected individuals, were contributing factors for contracting rubella. Rubella vaccine should be considered to prevent similar outbreaks.

BackgroundRubella virus (RuV), a single stranded RNA virus, has detrimental effects in pregnancy due to miscarriage and congenital rubella syndrome. RuV was declared eliminated from the United States in 2004 due to successful implementation of the combined measles, mumps, and rubella (MMR) vaccine.1 Despite this eradication, rubella virus (RuV)-associated granulomas have been reported in the literature but are limited to case reports and series, with no reported prevalence rate.2 This study aims to assess the prevalence of cutaneous RuV granulomas and to further characterize the disease.Table 1:Characteristics of patients by rubella statusTable 2:Granulomatous disease presentation and referral diagnosisMethodsA multicenter retrospective cohort study of adult patients with atypical granulomas on histopathology, defined as suppurative granulomatous inflammation without an infectious cause or a granulomatous pattern without a specified diagnosis, were included. RuV immunostaining was performed on paraffin-embedded cutaneous tissue by the Centers for Disease Control and Prevention (CDC). Demographics and record review were collected.ResultsOf 117 patients, 71 were RuV-positive (61%) with a mean age of 53.44 ± 15.35; 61% were female (Table 1). RuV-positive lesions predominantly occurred on the extremities (80%, p=0.04) followed by head/neck (7%) and trunk (7%). Known immunocompromised status was not more prevalent in RuV-positive cases compared to RuV-negative (p=0.31). A third of cases came from outside referrals with a presumed diagnosis of both infectious and noninfectious etiologies (Table 2). Of the RuV-positive cases, 77% received one or more therapies. Biologics were used for 27% of patients, with TNF inhibitors most commonly used (72%).ConclusionIn this study, a high number of atypical cutaneous granulomas are positive for RuV (61%) with a predilection for the extremities. Atypical granulomas with extensive and unrevealing results should prompt testing for RuV. Future directions include thorough evaluation of patients, potential shedding into the environment and identification of best therapeutic interventions, including effective anti-virals against RuV. There is a need for prospective analysis to determine if RuV is vaccine-derived or wild type to further support public health interventions.DisclosuresMisha Rosenbach, MD, Johnson & Johnson: Advisor/Consultant|Merck: Advisor/Consultant|Novartis: Advisor/Consultant|Priovant: Advisor/Consultant|Priovant: Grant/Research Support Bridget Shields, MD, Priovant Therapeutics: Advisor/Consultant|UpToDate: Chapter Author Beth Drolet, Md, Arkayli: Board Member|Arkayli: Owner|Arkayli: Ownership Interest Megan Noe, MD, MPH, MSCE, Boehringer Ingelheim: Advisor/Consultant|Boehringer Ingelheim: Grant/Research Support|Bristol Meyer Squibb: Grant/Research Support|Sanofi: Employee|Takeda: Advisor/Consultant

BackgroundOutpatient clinical encounters for pre-travel counseling and the evaluation of latent tuberculosis infection (LTBI) are common in infectious disease practice but not in general internal medicine practice. As such, incoming infectious disease fellows may lack confidence in their approach to these unique encounters. To address this, we implemented a low-stakes role play into our introductory ID fellowship curriculum, using Kern’s model of curriculum development and a modified Sawyer’s pedagogical framework.Abbreviations: IGRA, interferon-gamma release assay; LTBI, latent tuberculosis infection; MMR, measles, mumps, and rubellaMethodsIn the first month of fellowship, a core lecture series on pre-travel counseling and LTBI preceded low-stakes, formative role-play sessions, which paired one faculty (the “patient”) with one fellow (the “provider”) to simulate discrete, standardized clinical scenarios for each topic. Real-time and/or post-encounter feedback was provided, as needed. Self-reported fellow confidence in knowledge and abilities were surveyed on a 10-point Likert scale pre- and post-session. Data were analyzed using the Mann-Whitney U test.Results10 fellows (5/first-year class in each of the 2023-2024 and 2024-2025 academic years) participated. Fellow confidence in their self-assessed knowledge increased significantly in all 6 measured domains (Table 1). Fellow confidence in their self-assessed ability increased significantly in 7/10 domains. Confidence did not differ in their perceived ability to counsel a patient on traveler’s diarrhea, explain the difference in treatment options for traveler’s diarrhea, or to understand and explain the importance of the measles, mumps, and rubella (MMR) vaccination. Free-text feedback showed that fellows valued the formative and realistic nature of the encounters, with recommendations for allowing observation of a clinical encounter by an experienced physician and access to additional preparatory materials.ConclusionThis low-stakes, high-fidelity role-play innovation demonstrated improved fellow confidence in their knowledge and abilities to approach common outpatient ID scenarios, and it was well-received by the fellows. Incorporating role-play clinical scenarios to fill curriculum gaps may benefit other programs as a tool to build clinical skills and guide further curriculum development.DisclosuresAll Authors: No reported disclosures

IntroductionThis study examines the relationship between social vulnerability and up-to-date (UTD) primary vaccine coverage among children with sickle cell disease (SCD).MethodsThis retrospective cohort study included children with SCD born in Georgia between 2008 and 2019, identified through the state newborn screening program. Immunization records were obtained from the state registry, and birth addresses were matched to census tract level Social Vulnerability Index (SVI) scores. Children were considered UTD if they completed the recommended vaccine doses by 24 months. Multivariable logistic regression assessed the association between overall and subtheme SVI scores and vaccine completion, adjusting for demographic and clinical covariates.ResultsThe study included 1,337 children with SCD. Of these, 37% lived in areas with the highest SVI vulnerability, and 12% lived in the least vulnerable areas. Overall, 58% of children were UTD with their primary vaccine series. Children with moderate or high vulnerability in the socioeconomic subtheme had significantly higher odds of having UTD poliovirus vaccine, measles, mumps, and rubella vaccine, haemophilus influenzae type-b vaccine, and hepatitis B vaccine compared to children with low vulnerability. Higher vulnerability in the housing type and transportation marginally decreased the odds of completing the diphtheria, tetanus, and acellular pertussis vaccine.DiscussionChildren with SCD are disproportionately concentrated in areas of high social vulnerability. The SVI can help identify neighborhoods for targeted vaccine outreach, especially in communities with high housing and transportation vulnerability. Efforts should prioritize multi-dose vaccines and the varicella vaccine.

A total of 1723 measles cases have been reported as of November 12, 2025, in the US, reaching their highest levels since elimination in 2000. MMR (measles, mumps, and rubella) vaccination coverage has decreased, and factors associated with delayed and missed vaccination since the COVID-19 pandemic are not well explored. To characterize coverage and trends of timely MMR vaccination and assess factors associated with late vaccination and nonvaccination by 2 years of age. In this cohort study, infants who accessed routine care within the first 2 months, first year, and second year of life were followed up for 24 months to assess vaccination outcomes between January 1, 2018, and April 30, 2025. Participants were children seeking care within Truveta Data, an electronic health record database from a collective of US health care systems. Timely receipt of routine 2- and 4-month immunizations and adherence to the American Academy of Pediatrics well child visit schedule. The primary outcome was timely, late, or no receipt of MMR by 2 years of age. Associations with primary exposures and sociodemographic factors were modeled using mixed-effect logistic regression with state-level random effects. Models were stratified by pre- vs post-COVID-19 MMR eligibility, with results after the COVID-19 pandemic reported as primary. In this study of 321 743 children (166 017 boys [51.6%]) with regular access to care, 78.4% (252 250 of 321 743) received their first MMR vaccination on time, increasing from 75.6% (12 840 of 16 978) in 2018 to 79.9% (39 739 of 49 767) in 2021, then decreasing to 76.9% (40 306 of 52 388) in 2024. The strongest factors associated with no MMR vaccination by 2 years was late administration of a child's 2-month vaccines (adjusted odds ratio [AOR], 6.96 [95% CI, 6.60-7.34]) and 4-month vaccines (AOR, 6.16 [95% CI, 5.84-6.50]). In this cohort study of children with regular access to care, most received their MMR vaccine on time, but the proportion not receiving the MMR vaccine by 2 years of age has increased since the COVID-19 pandemic. Children who did not receive their 2- and 4-month vaccines on time were significantly more likely to not receive any MMR vaccine by 2 years, highlighting opportunities for intervention.

Misinformaion and its impact on measles vaccine hesitancy in the pediatric population: A scoping review.

ABSTRACT JVC-001 is a novel measles-mumps-rubella (MMR) combined vaccine. In the J301 clinical trial, healthy 1-y-old Japanese children received either JVC-001 or marketed measles-rubella (MR) and mumps vaccines as control group. Our aim was to compare the long-term results between these two groups. From the 861 participants in the J301 study, 502 were followed for approximately 4 y. Antibody titers were measured using measles neutralizing test (NT), rubella hemagglutination inhibition (HI), mumps plaque reduction NT (PRNT) against genotype D and NT against genotype G in total of 446 participants (216 in the JVC-001 group, 230 in the control group). No participants in either group were identified as having measles, rubella, or mumps during the study period. Seropositive rates of measles NT, rubella HI, mumps PRNT (genotype D) and mumps NT (genotype G) in the JVC-001 group were 93.5%, 98.6%, 91.7%, and 88.9%, respectively. The control group rates were 88.7%, 99.1%, 92.4%, and 87.4%, respectively. JVC-001 maintained antibodies against measles, rubella, and mumps for approximately 4 y, with comparable persistence to marketed vaccines. The results suggested that protective serum antibodies are maintained until the second dose of MMR vaccine is administered in a Japanese pediatric population. Trial registration: jRCTs031230590.

Background: Women’s empowerment has been significantly associated with improved child health outcomes. Cambodia, amid a rapid socioeconomic transition, offers a critical setting to examine how advancements in women’s empowerment over the past decade have influenced child immunization completion within the first two years of life. Methods: Data from the Cambodia Demographic and Health Surveys conducted in 2010, 2014, and 2021–22, encompassing 9222 women with recent births, were analyzed. Empowerment was measured across literacy and information access, employment, and decision-making domains. Multinomial logistic regression assessed associations between empowerment factors and completion of oral polio (OPV), diphtheria–tetanus–pertussis (DTP), pneumococcal conjugate (PCV), and measles–rubella (MR) vaccines, adjusting for demographic and socioeconomic variables. Results: Between 2010 and 2022, women’s empowerment in Cambodia improved significantly, marked by higher literacy rates, nearly half of women completing primary education, and expanded digital access, with 82.4% owning mobile phones and approximately 50% using the internet daily. While non-working women slightly increased, agricultural employment declined by 20%, and cash earnings rose from 48.7% to 82.5%. Most women participated in major household decision-making, either independently or jointly. Completion rates for OPV, DTP, and PCV ranged from 79% to 83%, while just over half of children were fully vaccinated against measles. Higher maternal education and cash earnings were positively associated with OPV, DTP, and PCV completion but negatively associated with measles vaccination. Women in agricultural work were less likely to complete measles vaccination for their children than non-working women. Joint decision-making regarding the use of respondents’ income was associated with a higher likelihood of measles non-completion (OR = 2.26, 95% CI: 1.13–4.51), whereas joint decision-making about respondents’ health care was associated with a higher likelihood of measles completion (OR = 0.42, 95% CI: 0.21–0.83). Conclusions: Women’s empowerment remains a key determinant of vaccination outcomes in Cambodia. The distinct pattern observed for measles suggests that vaccines scheduled for older ages encounter greater structural and behavioral barriers. To overcome these challenges, strategies should focus on enhancing defaulter tracking, implementing reminder systems, expanding outreach and catch-up programs, and improving the convenience of vaccination services.

ABSTRACT Measles, mumps, rubella, and varicella (MMRV) vaccines are widely used in global immunization programs, but safety data on their administration in children remain limited. We analyzed adverse events following immunization(AEFIs) associated with the MMRV vaccine in children under seven y of age, as reported to the US Vaccine Adverse Event Reporting System (VAERS) from 2005 to 2025. Disproportionality analyses were applied, with multiple testing correction using a 5% false discovery rate. Subgroup assessments focused on children with asthma, epilepsy, and chronic kidney disease. The results show that among the 13,724 reports, 94.1% were non-serious cases, and the signal of Conjunctival Disorder had the highest reporting rate (ROR = 61.13, 95%confidence interval[CI]: 6.36-587.74). The risk of seizures in children with epilepsy significantly increased (ROR = 10.27, 95% CI: 6.57-16.05), with 63.2% occurring within 48 h after vaccination; a 6.81-fold increase in ROR was observed in the risk of wheezing in children with asthma, and no significant risk increment was observed in the chronic kidney disease group. Susceptibility to risks varied across subgroups. Weibull distribution analysis indicated that AEFIs following MMRV exhibited early-onset characteristics. This study provides a comprehensive understanding of MMRV vaccine safety and highlights the need for targeted protective measures in children with epilepsy and asthma to reduce vaccine hesitancy and improve vaccination coverage.

BackgroundPROQUAD®, a quadrivalent live-attenuated vaccine targeting measles, mumps, rubella, and varicella, is widely used in pediatric immunization programs. While clinical trials and post-marketing studies have established its general safety, real-world evidence from large-scale passive surveillance systems remains limited.MethodsWe performed a disproportionality analysis of PROQUAD-related adverse events (AEs) reported to the Vaccine Adverse Event Reporting System (VAERS) between 2015 and 2025. Multiple statistical algorithms were applied to detect safety signals, supplemented by stratified analyses across age, sex, severity, and fatal outcomes.ResultsAmong 17,234 reports, the most frequently reported AEs included injection site erythema, swelling, and fever, consistent with established reactogenicity. Several statistically significant signals not listed in the current FDA label were identified, such as febrile convulsion, vaccination failure, cyanosis, and influenza-like illness. These unlabeled events exhibited distinct patterns across age and sex subgroups, with serious and fatal outcomes occurring more frequently in children under three years of age and in medically vulnerable individuals. Most AEs occurred within three days of vaccination, although serious events showed delayed onset profiles.ConclusionThis real-world pharmacovigilance analysis confirms the expected safety profile of PROQUAD while revealing additional adverse event signals that merit further clinical investigation and potential regulatory attention. Continued monitoring is essential to inform vaccine safety practices, particularly in pediatric populations with heightened susceptibility.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12985-025-03022-z.

Subacute sclerosing panencephalitis (SSPE) is a rare, fatal complication of measles, manifesting years after infection due to persistent measles virus in the central nervous system. An 11-year-old Syrian boy with prior measles and measles - mumps - rubella (MMR) vaccination developed progressive encephalopathy and a vegetative state. MRI showed diffuse white matter, thalamic, and pontine changes; SSPE was confirmed post-mortem. This case emphasises the need for high MMR vaccine coverage and the importance of clinical awareness of rare infectious diseases in patients from crisis-affected countries.

Vaccination prevents millions of childhood deaths annually, yet 23 million infants still miss essential vaccines, mostly in Sub-Saharan Africa. Low coverage is particularly concerting in countries with high paediatric HIV prevalence. In Equatorial Guinea, where 6% of children live with HIV and vaccination coverage remains limited, information on vaccine-induced immunity is scarce. We conducted a cohort study to evaluate immunity against six vaccine-preventable diseases in HIV-exposed children from Bata. Plasma samples from 69 children (55 HIV+/14 exposed uninfected) collected between 2019 and 2021 were analysed by a chemiluminescent immunoassay. Despite antiretroviral therapy, only 18.5% of HIV + children achieved viral suppression. Reported vaccination coverage for DTP and measles was lower than WHO-UNICEF estimates. IgG antibody levels was 68.1% for diphtheria, 13% for tetanus, 5.8% for pertussis, and 49.3% for measles. Although mumps and rubella vaccines are not included in the national schedule, antibody prevalence was 79.7% and 59.4%, respectively, suggesting natural exposure. Vaccination records were incomplete for half of the children. HIV-exposed children in EG show insufficient antibody levels against major vaccine-preventable pathogens. Strengthening immunization services, improving vaccine record systems, and tailoring strategies for HIV-exposed children are critical priorities.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-28643-w.

A third dose of measles, mumps, and rubella vaccine (MMR3) may be administered in outbreak and nonoutbreak settings. However, data on long-term immunogenicity to the mumps component of MMR are limited. We examined durability of mumps antibody response among adults up to 11 years after receipt of MMR3. Persons who received MMR3 at ages 18-28 years had sera collected before (baseline), 1 month, 1, 5, and 9-11 years after vaccination. Mumps antibodies were assessed by plaque reduction neutralization, immunoassay (EIA), and immunoglobulin G (IgG) avidity. Neutralizing antibodies were assessed against the vaccine strain (Genotype A) and a wild-type virus from Genotype G. Participants with neutralizing antibody titers <31 for Genotype A and <8 for Genotype G, and with EIA index values <1.10 were considered potentially susceptible. Among participants with data for all visits after MMR3 (40%, n = 262/655), susceptibility based on Genotype A titers increased from 15.7% (41/262) at baseline to 30.5% (80/262) 9-11 years after vaccination while susceptibility based on Genotype G titers remained relatively stable (30.2%-24.2%). The proportion of participants seronegative for mumps IgG by EIA increased from 0% (0/255) at baseline to 7.5% (19/255) 9-11 years after vaccination. The avidity index increased from 52% to 67% through Year 5 (P < .0001). By 9-11 years after receipt of MMR3, many participants had mumps antibody levels that predicted susceptibility to infection, comparable to those observed before receipt of MMR3. The antibody titers to Genotype G remained consistently lower than the titers to the vaccine strain.