Recent Surge in Mumps Cases in India: Need for Urgent Remedial Measures.

Mumps is a global public health problem caused by mumps virus, a member of paramyxoviridae family. MMR (Mumps, Measles, Rubella), an effective vaccine, has been incorporated into routine immunization schedules in over 100 countries. On the contrary, in India, vaccine against mumps has not been included in the routine immunization schedule as mumps is still not viewed as a significant public health problem by the government to warrant such an intervention. An increasing number of mumps outbreaks being reported from many parts of the country in the recent past, is matter of concern. The current paper reviews the situation of mumps in India including the recent surge, and discusses the remedial measures to contain these outbreaks. We conclude that inclusion of Mumps component as MMR vaccine in the Universal Immunization Programme of India along with strengthening surveillance is required to tackle the situation.

Early B cell transcriptomic markers of measles-specific humoral immunity following a 3rd dose of MMR vaccine.

B cell transcriptomic signatures hold promise for the early prediction of vaccine-induced humoral immunity and vaccine protective efficacy. We performed a longitudinal study in 232 healthy adult participants before/after a 3rd dose of MMR (MMR3) vaccine. We assessed baseline and early transcriptional patterns in purified B cells and their association with measles-specific humoral immunity after MMR vaccination using two analytical methods ("per gene" linear models and joint analysis). Our study identified distinct early transcriptional signatures/genes following MMR3 that were associated with measles-specific neutralizing antibody titer and/or binding antibody titer. The most significant genes included: the interleukin 20 receptor subunit beta/IL20RB gene (a subunit receptor for IL-24, a cytokine involved in the germinal center B cell maturation/response); the phorbol-12-myristate-13-acetate-induced protein 1/PMAIP1, the brain expressed X-linked 2/BEX2 gene and the B cell Fas apoptotic inhibitory molecule/FAIM, involved in the selection of high-affinity B cell clones and apoptosis/regulation of apoptosis; as well as IL16 (encoding the B lymphocyte-derived IL-16 ligand of CD4), involved in the crosstalk between B cells, dendritic cells and helper T cells. Significantly enriched pathways included B cell signaling, apoptosis/regulation of apoptosis, metabolic pathways, cell cycle-related pathways, and pathways associated with viral infections, among others. In conclusion, our study identified genes/pathways linked to antigen-induced B cell proliferation, differentiation, apoptosis, and clonal selection, that are associated with, and impact measles virus-specific humoral immunity after MMR vaccination.

Measles - United States, January 1, 2020-March 28, 2024.

Measles is a highly infectious febrile rash illness and was declared eliminated in the United States in 2000. However, measles importations continue to occur, and U.S. measles elimination status was threatened in 2019 as the result of two prolonged outbreaks among undervaccinated communities in New York and New York City. To assess U.S. measles elimination status after the 2019 outbreaks and to provide context to understand more recent increases in measles cases, CDC analyzed epidemiologic and laboratory surveillance data and the performance of the U.S. measles surveillance system after these outbreaks. During January 1, 2020-March 28, 2024, CDC was notified of 338 confirmed measles cases; 97 (29%) of these cases occurred during the first quarter of 2024, representing a more than seventeenfold increase over the mean number of cases reported during the first quarter of 2020-2023. Among the 338 reported cases, the median patient age was 3 years (range = 0-64 years); 309 (91%) patients were unvaccinated or had unknown vaccination status, and 336 case investigations included information on ≥80% of critical surveillance indicators. During 2020-2023, the longest transmission chain lasted 63 days. As of the end of 2023, because of the absence of sustained measles virus transmission for 12 consecutive months in the presence of a well-performing surveillance system, U.S. measles elimination status was maintained. Risk for widespread U.S. measles transmission remains low because of high population immunity. However, because of the increase in cases during the first quarter of 2024, additional activities are needed to increase U.S. routine measles, mumps, and rubella vaccination coverage, especially among close-knit and undervaccinated communities. These activities include encouraging vaccination before international travel and rapidly investigating suspected measles cases.

A national registry-based study on uptake of the first dose of MMR vaccine in 380 administrative regions in Poland, 2013-2016-2020.

INTRODUCTION AND OBJECTIVE: Regular monitoring of the measles, mumps, and rubella (MMR) vaccine uptake quickly exposes immunity gaps in the population. In Poland, the first dose of the MMR vaccine is mandatory for children between 13 and 15 months of life. This study aimed to assess the uptake of the first dose of MMR vaccine in 380 administrative counties in Poland in 2020, as well as to analyze the MMR vaccine uptake trends in 2013-2016-2020. MATERIAL AND METHODS: This study is an epidemiological retrospective national registry-based analysis. Data on mandatory childhood vaccinations in all 380 counties in Poland were collected from the epidemiological reports of the State Sanitary Inspectorate territorial representatives. MMR vaccine uptake was calculated as the percentage of children who received the first dose of MRR vaccine to all children subject to mandatory vaccination in the county. RESULTS: The uptake of the first dose of MMR vaccine decreased from 99.4% in 2013, to 95.5% in 2016 and 91.9% in 2020. In 2013, 93.2% of countys MMR vaccine uptake level reached the herd immunity level, followed by 77.1% of counties in 2016 and only 38.3% of countys in 2020. In 2020, two counties reached complete (100%) MMR vaccine uptake, and the lowest MMR vaccine uptake was 63.88%. Of the 380 counties in Poland, in 226 (61.1%) the MMR vaccine uptake level was lower than the herd immunity level, and a downward trend was observed. MMR vaccine uptake decreased with an increased number of residents in a county (r= -0.35; p<0.001). CONCLUSIONS: This study revealed that in 61% of administrative regions in Poland, the MMR vaccine uptake was below the herd immunity level. Regional differences in the MMR vaccine uptake were observed. A significant decrease in MMR vaccine uptake between 2013 - 2020 poses a risk of measles outbreaks.

Implications of Measles Inclusion by Commercial Syndromic Polymerase Chain Reaction Panels - United States, May 2022-April 2023.

Syndromic polymerase chain reaction (PCR) panels are used to test for pathogens that can cause rash illnesses, including measles. Rash illnesses have infectious and noninfectious causes, and approximately 5% of persons experience a rash 7-10 days after receipt of a measles, mumps, and rubella (MMR) vaccine. MMR vaccine includes live attenuated measles virus, which is detectable by PCR tests. No evidence exists of person-to-person transmission of measles vaccine virus, and illness does not typically result among immunocompetent persons. During September 2022-January 2023, the Tennessee Department of Health received two reports of measles detected by syndromic PCR panels. Both reports involved children (aged 1 and 6 years) without known risk factors for measles, who were evaluated for rash that occurred 11-13 days after routine MMR vaccination. After public health responses in Tennessee determined that both PCR panels had detected measles vaccine virus, six state health departments collaborated to assess the frequency and characteristics of persons receiving a positive measles PCR panel test result in the United States. Information was retrospectively collected from a commercial laboratory testing for measles in syndromic multiplex PCR panels. During May 2022-April 2023, among 1,548 syndromic PCR panels, 17 (1.1%) returned positive test results for measles virus. Among 14 persons who received a positive test result and for whom vaccination and case investigation information were available, all had received MMR vaccine a median of 12 days before specimen collection, and none had known risk factors for acquiring measles. All positive PCR results were attributed to detection of measles vaccine virus. Increased awareness among health care providers about potential measles detection by PCR after vaccination is needed. Any detection of measles virus by syndromic PCR testing should be immediately reported to public health agencies, which can use measles vaccination history and assessment of risk factors to determine the appropriate public health response. If a person recently received MMR vaccine and has no risk factors for acquiring measles, additional public health response is likely unnecessary.

A Review of the Resurgence of Measles, a Vaccine-Preventable Disease, as Current Concerns Contrast with Past Hopes for Measles Elimination.

On 22 February 2024, the World Health Organization (WHO) stated that, following the recent resurgence of measles cases in Europe, more than half the world's countries could expect significant measles outbreaks this year. Measles is a highly infectious virus with a primary case reproduction number (R0) of 12-18. Measles infection can be severe, resulting in pneumonia, and also more rarely in subacute sclerosing panencephalitis (SSPE), which occurs in 1 child out of every 1,000 and can be fatal. Until the 1990s, the hope of eliminating measles seemed possible following the successful development of effective vaccines, given individually or in the combined measles, mumps, and rubella (MMR) vaccine. Vaccine hesitancy due to misinformation about possible vaccine side effects, reduced vaccine uptake during and after the COVID-19 pandemic, and lack of awareness of the severe consequences of measles infection have contributed to low vaccine uptake, resulting in vulnerable communities. This article aims to review the recent resurgence of measles cases in the US, Europe, and the UK, to provide a reminder of the potential severity of measles, and to consider the causes of the failure to eliminate this vaccine-preventable viral infection.

Live vaccinations in dermatology for immunosuppressed patients: a narrative review.

Given the higher susceptibility to infectious disease in patients receiving immunosuppressive therapies for inflammatory dermatologic conditions, immunization is important in this population. While live vaccines protect against life-threatening diseases, they can be harmful in immunosuppressed patients given the risk of replication of the attenuated pathogen and adverse reactions. The utilization of live vaccines in immunosuppressed patients depends on multiple factors such as the vaccine and therapy regimen. To provide an overview of evidence-based recommendations for the use of live vaccines in patients receiving immunosuppressive therapies for dermatological conditions. A literature search of the PubMed database was performed using keywords live vaccine, live-attenuated vaccine, dermatology, immunosuppressed, and immunocompromised, and specific immunosuppressive therapies: corticosteroids, glucocorticoids, methotrexate, azathioprine, cyclosporine, mycophenolate mofetil, biologics. Relevant articles written in English were included. Using these keywords, 125 articles were reviewed, of which 28 were ultimately selected. Recommendations for live vaccines can be determined on a case-by-case basis. Measles, mumps, rubella, varicella (MMRV) vaccines may be safely administered to patients on low-dose immunosuppressive agents while the yellow fever vaccine is typically contraindicated. It may be safe to administer live MMRV boosters to children on immunosuppressive therapies and the live herpes zoster vaccine to patients on biologics. Given poor adherence to immunization guidelines in immunosuppressed patients, dermatologists have a critical role in educating patients and general practitioners regarding live vaccines. By reviewing a patient's vaccination history and following immunization guidelines prior to initiating immunosuppressive therapies, physicians can mitigate morbidity and mortality from vaccine-preventable diseases.

Is vaccination against measles, mumps, and rubella associated with reduced rates of antibiotic treatments among children below the age of 2 years? Nationwide register-based study from Denmark, Finland, Norway, and Sweden.

OBJECTIVES: Previous studies have shown that vaccination against measles, mumps, and rubella (MMR) may have beneficial non-specific effects, reducing the risk of infections not targeted by the vaccine. We investigated if MMR vaccine given after the third dose of diphtheria-tetanus-acellular pertussis vaccine (DTaP3), was associated with reduced rates of antibiotic treatments. METHODS: Register-based cohort study following children from the age of recommended MMR vaccination until age 2 years. We included 831,287 children born in Denmark, Finland, Norway, and Sweden who had received DTaP3 but not yet MMR vaccine. Cox proportional hazards regression with age as the underlying timescale and vaccination status as a time-varying exposure was used to estimate covariate-adjusted Hazard Ratios (aHRs) and inverse probability of treatment weighted (IPTW) HRs of antibiotic treatments. Summary estimates were calculated using random-effects meta-analysis. RESULTS: Compared with only having received DTaP3, receipt of MMR vaccine after DTaP3 was associated with reduced rates of antibiotic treatments in all countries: the aHR was 0.92 (0.91-0.93) in Denmark, 0.92 (0.90-0.94) in Finland, 0.84 (0.82-0.85) in Norway, and 0.87 (0.85-0.90) in Sweden, yielding a summary estimate of 0.89 (0.85-0.93). A stronger beneficial association was seen in a negative control exposure analysis comparing children vaccinated with DTaP3 vs two doses of DTaP. CONCLUSIONS: Across the Nordic countries, receipt of MMR vaccine after DTaP3 was associated with an 11% lower rate of antibiotic treatments. The negative control analysis suggests that the findings are affected by residual confounding. Findings suggest that potential non-specific effects of MMR vaccine are of limited clinical and public health importance for the milder infections treated out-of-hospital in the Nordic setting.

A case series of live attenuated vaccine administration in dupilumab-treated children with atopic dermatitis.

BACKGROUND AND OBJECTIVE: Current regulatory labeling recommends avoiding live vaccine use in dupilumab-treated patients. Clinical data are not available to support more specific guidance for live or live attenuated vaccines administration in dupilumab-treated patients. METHODS: Children (6 months-5 years old) with moderate-to-severe atopic dermatitis (AD) enrolled in a phase 2/3 clinical trial of dupilumab (LIBERTY AD PRESCHOOL Part A/B; NCT03346434) and subsequently participated in the LIBERTY AD PED-OLE (NCT02612454). During these studies, protocol deviations occurred in nine children who received measles, mumps, rubella (MMR) vaccine with or without varicella vaccine; five with a ≤12-week gap between dupilumab administration and vaccination and four with a >12-week gap after discontinuing dupilumab. RESULTS: Nine children (1 female; 8 male) had severe AD at baseline (8-56 months old). Of the nine children, five had a ≤12-week gap ranged 1-7 weeks between dupilumab administration and vaccination who received MMR vaccine (n = 2) or MMR and varicella vaccines (n = 3); among these, one resumed dupilumab treatment as early as 2 days and four resumed treatment 18-43 days after vaccination. No treatment-emergent adverse events, including serious adverse events and infections, were reported within the 4-week post-vaccination period in any children. CONCLUSIONS: In this case series of dupilumab-treated children with severe AD who received MMR vaccine with or without varicella vaccine, no adverse effects (including vaccine-related infection) were reported within 4 weeks after vaccination. Further studies are warranted to evaluate the safety, tolerability, and immune response to live attenuated vaccines in dupilumab-treated patients.

Effectiveness of the combined MMRV Priorix-Tetra™ vaccine against varicella in a large Italian region: A case-control study.

Priorix-Tetra™ (MMRV GlaxoSmithKline Biologicals' vaccine) was developed based on the existing measles-mumps-rubella and varicella vaccines. In this study, we aimed to estimate the effectiveness of the combined measles-mumps-rubella-varicella Priorix-Tetra™ vaccine against varicella in real-world conditions. We conducted a post-marketing retrospective case-control study in the Apulia region of Italy in children aged 1-9 years born between January 1, 2008 and December 31, 2016. We assessed the effectiveness against varicella of all grades of severity (including hospitalisation) and against hospitalisation for varicella of a single and two doses of Priorix-Tetra™. Moreover, we also assessed effectiveness of monovalent varicella (monovalent-V) vaccine and any varicella vaccines. Vaccine effectiveness was calculated as (1-OR) x 100. We introduced demographic variables in the model to adjust Vaccine effectiveness (aVE) by potential confounders (sex and year of birth). We recorded 625 varicella cases and matched them with 1,875 controls. Among 625 cases, 198 had received a single MMRV dose, 10 two MMRV doses, 46 a single monovalent-V dose, none two monovalent-V doses; four a monovalent-V as first dose and MMRV as second dose, and one a MMRV as first dose and monovalent-V as second dose; 366 cases were not vaccinated. The aVE against varicella of all grades of severity was 77.0% and 93.0% after a single dose and after two doses of MMRV, respectively. The aVE against varicella of all grades was 72.0% after a single dose of monovalent-V vaccine. The aVE against varicella of all grades of severity was 76.0% after a single dose and 94.0% after two doses of any varicella vaccine. The aVE against varicella hospitalisation was 96% after a single dose of any varicella vaccine. Priorix-Tetra™ showed to be an effective vaccine and the two-dose schedule should be recommended to optimise immunisation programmes. A single dose was able to provide protection against varicella hospitalisation.

Neutralizing antibody titers against D8 genotype and persistence of measles humoral and cell-mediated immunity eight years after the first dose of measles, mumps, and rubella vaccine in Brazilian children.

OBJECTIVE: Assess the level of measles vaccine-induced neutralizing antibodies against the D8 genotype and the persistence of humoral and cell-mediated immunity in children who received their first dose of the measles, mumps, and rubella vaccine eight years previously. METHODS: Measles-specific IgG and neutralizing antibodies were determined in serum using ELISA and plaque reduction neutralization test, respectively. Cellular response was evaluated from peripheral blood mononuclear cells (PBMC). IFN-γ-secreting cells, memory B and T cells, and immunological mediators were assayed by ELISpot, flow cytometry, and multiplex liquid microarray assay, respectively. RESULTS: Antibody concentrations declined over time; however, the vaccine-induced neutralizing antibodies' effect against D8 and vaccinal genotypes persisted. PBMC stimulated with the vaccine virus exhibited specific IFN- γ-measles-secreting responses in most participants. Participants with high levels of neutralizing antibodies showed a higher proportion of activated B cells compared to participants with low levels of neutralizing antibodies, while proportions of memory CD4+ and CD8+ T cells were similar between these groups. PBMC supernatant cytokine levels showed a significant difference between stimulated and non-stimulated conditions for IL-2, TNF-α, IL-10, and CXCL10. CONCLUSION: Despite the decline in antibody concentrations over time, the participants still demonstrated neutralizing capacity against the measles D8 genotype five to eight years after the second dose of the measles, mumps, and rubella vaccine. Additionally, most of the enrolled children exhibited cell-mediated immunity responses to measles virus stimulation.

Measles vaccination - An underestimated prevention measure: Analyzing a fatal case in Hildesheim, Germany.

Measles and rubella are targeted for elimination in the WHO region Europe. To reach the elimination goal, vaccination coverage of 95% must be achieved and sustained, the genotype information has to be provided for 80% of all outbreaks and transmission chains of a certain variant must not be detected for >12 months. The latter information is collected at Germany's National Reference Center Measles, Mumps, Rubella (NRC MMR). We describe here an outbreak of measles occurring in Hildesheim. The outbreak comprised 43 cases and lasted 14 weeks. Surprisingly, a high number of vaccination failures was observed since 11 cases had received two doses of the MMR vaccine and 4 additional cases were vaccinated once. A 33-year-old woman passed away during the outbreak. She was the mother of 5 children between 4 and 16 years of age. Two schoolchildren contracted measles and passed it on to the rest of the family. Due to delivery bottlenecks, the vaccination of the mother was delayed. She developed measles-like symptoms 3 days after vaccination and was found dead on the morning of day 8 after vaccination. A post-mortem examination was done to identify the cause of death. Moreover, molecular characterization of the virus was performed to analyze whether she was infected by the wildtype virus circulating at that time in Hildesheim or whether the vaccine may have been a concomitant and aggravating feature of her death. The result showed that the samples taken from her at the time of death and during necropsy contained the wildtype measles virus variant corresponding to MVs/Gir Somnath.IND/42.16 (WHO Seq-ID D8-4683) that fueled the Hildesheim outbreak and circulated in Germany from March 2018 to March 2020. The vaccine virus was not detected. Moreover, two aspects uncovered by the post-mortem examination were remarkable; the woman died from giant cell pneumonia, which is a complication seen in immune-suppressed individuals and she was actively using cannabis. THC is known to influence the immune system, but literature reports describing the effects are limited.

Immunity Rates of Live Viral Vaccines in Pediatric Renal Transplant Candidates: A Single-Center Experience.

OBJECTIVES: Solid-organ transplant recipients are at an increased risk of severe infections due to their immunosuppressed state. Despite the recommendation of routine screening and vaccination before transplant to mitigate this danger, vaccination rates in these patients are still below desirable levels. We aimed to investigate the prevalence of positive antibody rates for measles, mumps, rubella, and varicella among children who are candidates for renal transplant. MATERIALS AND METHODS: This retrospective study was conducted at a single center and included 144 pediatric kidney transplant patients for the past 7 years. We reviewed the medical records of all participants to evaluate their serologic status for measles, mumps, rubella, and varicella viruses before kidney transplant. RESULTS: In this study, 144 pediatric kidney transplant candidates (mean age 11.5 years, 56.9% male) were enrolled, and the most frequent causes of the chronic renal disease were congenital anomalies of the kidney and urinary tract and glomerular diseases (32.6%). Seropositivity rates for measles, mumps, rubella, and varicella were 59.0%, 31.9%, 46.5%, and 43.6%, respectively, and all patients who tested negative for antibodies were vaccinated before transplant. Younger age at transplant (OR = 0.909, 95% CI = 0.840-0.923; P = .017) and congenital anomalies of the kidney and urinary tract (OR = 3.46, 95% CI = 1.1548-7.735; P = .002) were significantly associated with increased measles seropositivity, although no significant associations were observed for the other viruses. CONCLUSIONS: We observed lower seropositivity rates for measles, mumps, rubella, and varicella in pediatric kidney transplant patients versus healthy children and other previous studies. It is essential to address these suboptimal rates to protect the health of these vulnerable patients. Future research should focus on targeted interventions to improve vaccination rates and outcomes in this population.

Live-attenuated vaccination for measles, mumps, and rubella in pediatric liver transplantation.

BACKGROUND: Infections are a serious short- and long-term problem after pediatric organ transplantation. In immunocompromised patients, they can lead to transplant rejection or a severe course with a sometimes fatal outcome. Vaccination is an appropriate means of reducing morbidity and mortality caused by vaccine-preventable diseases. Unfortunately, due to the disease or its course, it is not always possible to establish adequate vaccine protection against live-attenuated viral vaccines (LAVVs) prior to transplantation. LAVVs such as measles, mumps, and rubella (MMR) are still contraindicated in solid organ transplant recipients receiving immunosuppressive therapy (IST), thus creating a dilemma. AIM: This review discusses whether, when, and how live-attenuated MMR vaccines can be administered effectively and safely to pediatric liver transplant recipients based on the available data. MATERIAL AND METHODS: We searched PubMed for literature on live-attenuated MMR vaccination in pediatric liver transplantation (LT). RESULTS: Nine prospective observational studies and three retrospective case series were identified in which at least 833 doses of measles vaccine were administered to 716 liver transplant children receiving IST. In these selected patients, MMR vaccination was well tolerated and no serious adverse reactions to the vaccine were observed. In addition, an immune response to the vaccine was demonstrated in patients receiving IST. CONCLUSION: Due to inadequate vaccine protection in this high-risk group, maximum efforts must be made to ensure full immunization. MMR vaccination could also be considered for unprotected patients after LT receiving IST following an individual risk assessment, as severe harm from live vaccines after liver transplantation has been reported only very rarely. To this end, it is important to establish standardized and simple criteria for the selection of suitable patients and the administration of the MMR vaccine to ensure safe use.

A review of potential use cases for measles-rubella, measles-mumps-rubella, and typhoid-conjugate vaccines presented on microarray patches.

As an innovative vaccine delivery technology, vaccine microarray patches could have a meaningful impact on routine immunization coverage in low- and middle-income countries, and vaccine deployment during epidemics and pandemics. This review of the potential use cases for a subset of vaccine microarray patches in various stages of clinical development, including measles-rubella, measles-mumps-rubella, and typhoid conjugate, highlights the breadth of their applicability to support immunization service delivery and their potential scope of utilization within national immunization programs. Definition and assessment of the use cases for this novel vaccine presentation provide important insights for vaccine developers and policymakers into the strengths of the public health and commercial value propositions, and the preparatory requirements for public health systems for the future rollout of vaccine microarray patches. An in-depth understanding of use cases for vaccine microarray patches serves as a foundational input to overcoming the remaining technical, regulatory, and financial challenges. Additional efforts will help to realize the potential of vaccine microarray patches as part of the global effort to improve the coverage and equity of national immunization programs.

Measles, mumps, rubella and varicella antibodies among international and domestic university students.

BACKGROUND: Vaccine-preventable infections are generally well controlled in Australia. However, gaps in immunity can lead to outbreaks and are important to identify. Young adults are a highly mobile population and a potential source of imported infections. We aimed to evaluate anti- measles, mumps, rubella and varicella (MMR&V) IgG seroprevalence and explore factors relating to antibody seropositivity. METHODS: A cross-sectional online survey was conducted among students from a large Australian university to collect demographic, vaccination, infection and travel characteristics. Blood samples were collected to measure MMR&V seroprevalence. Logistic regression was used to identify factors associated with seropositivity. RESULTS: Among 804 university students, seroprevalence (positive or equivocal) for measles was 82.3% (95% CI 79.6-84.8%), mumps 79.5% (95% CI 76.7-82.3%), rubella 91.5% (95% CI 89.6-93.5%) and varicella 86.2% (95% CI 84.1-88.8%), with 452 (56.2%, 95% CI 52.8-59.6) seropositive to all four viruses. Varicella seropositivity was highest in the older birth cohort (born 1988-1991). Measles seropositivity was higher for international students compared to domestic students. Among international students, mumps seroprevalence was significantly lower than measles and rubella seroprevalence. International travel in the previous 12 months was reported by 63.1% of students, but only 18.2% of travellers reported seeking pre-travel health advice prior to most recent international travel. CONCLUSIONS: Overall, this study suggests immunity to MMR&V is sub-optimal. We found the university student population to be highly mobile and unlikely to seek pre-travel advice; thus, they are a potential source of infection importation. The implementation of university immunization policies could address the gaps identified and our findings can inform the development of targeted vaccination campaigns.