Epidemiological characteristics and serological survey of mumps 15 years after MMR vaccine was included in the immunization program.

Mumps is a vaccine-preventable acute viral infectious disease. To understand the incidence of mumps and population immunity in Quzhou City after measles mumps rubella vaccine (MMR) was included in the immunization program, we analyzed the epidemiological characteristics of mumps cases from 2009 to 2023 and a cross-sectional serosurvey of IgG antibodies to mumps conducted in 2024. We found that 15 years after the MMR vaccine was included in the immunization program, the incidence of mumps was significantly reduced in all populations, but the incidence remained highest in vaccinated children aged 0-12 years. Vaccine escape may explain the high incidence of mumps in highly vaccinated populations. Updating vaccines or developing a new vaccine that targets multiple viral genotypes may be necessary to improve the effectiveness of the vaccine against infection and fully control infections and outbreaks. The positive rate and concentration of mumps IgG antibody were inconsistent with the incidence data. mumps IgG antibody is not an ideal substitute for immunity and cannot be used to accurately predict whether a target population is susceptible or protected. Natural infections may provide longer-lasting immunity than vaccination.

Possible counter-intuitive impact of local vaccine mandates for vaccine-preventable infectious diseases.

We modeled the impact of local vaccine mandates on the spread of vaccine-preventable infectious diseases, which in the absence of vaccines will mainly affect children. Examples of such diseases are measles, rubella, mumps, and pertussis. To model the spread of the pathogen, we used a stochastic SIR (susceptible, infectious, recovered) model with two levels of mixing in a closed population, often referred to as the household model. In this model, individuals make local contacts within a specific small subgroup of the population (e.g., within a household or a school class), while they also make global contacts with random people in the population at a much lower rate than the rate of local contacts. We considered what would happen if schools were given freedom to impose vaccine mandates on all of their pupils, except for the pupils that were exempt from vaccination because of medical reasons. We investigated first how such a mandate affected the probability of an outbreak of a disease. Furthermore, we focused on the probability that a pupil that was medically exempt from vaccination, would get infected during an outbreak. We showed that if the population vaccine coverage was close to the herd-immunity level, then both probabilities may increase if local vaccine mandates were implemented. This was caused by unvaccinated pupils possibly being moved to schools without mandates.

Assessing seropositivity of MMR antibodies in individuals aged 2-22: evaluating routine vaccination effectiveness after the 2003 mass campaign-a study from Iran's National Measles Laboratory.

BACKGROUND AND PURPOSE: The seroprevalence of antibodies against measles, mumps, and rubella (MMR) was evaluated 17 years following a mass vaccination campaign in individuals aged 2 to 22 years who had received routine immunization but were not eligible for an extended immunization program. METHODS: Samples were acquired from Iran's National Measles Laboratory (NML), with individuals showing positive IgM results excluded. Out of the samples collected in 2020, a random selection of 290 serum samples was chosen, representing individuals between the ages of 2 and 22 years from diverse regions in the country. These samples were subjected to analysis using an enzyme-linked immunosorbent assay (ELISA) to quantify specific IgG antibodies against MMR. RESULTS: The seroprevalence rates of antibodies for measles, mumps, and rubella were determined to be 76.2%, 89.3%, and 76.9%, respectively. Younger age groups exhibited higher seropositivity rates for measles and mumps, whereas the 7- to 11-year-old group demonstrated the highest seropositivity rate for rubella. A reduction in antibody status was observed from younger to older age groups, particularly those aged 17-22. CONCLUSION: The study unveiled suboptimal antibody levels for measles and rubella, highlighting the necessity for further investigation and potential adjustments to future vaccination strategies. Moreover, the decline in antibody status post-vaccination can accumulate in seronegative individuals over time, elevating the risk of outbreaks.

Genetic characteristic of mumps virus from 2012 to 2016 and its serum antibody level among general healthy population during 2018-2020 in Jiangsu Province, China.

Mumps is a vaccine-preventable disease with high contagious capability. Its incidence declined rapidly since one dose of mumps vaccine was introduced into Expanded Program of Immunization (EPI) in 2008 in China. Nonetheless, the outbreaks of mumps remain frequent in China. Here we aim to assess herd immunity level followed by one-dose mumps ingredient vaccine and to elucidate the genetic characteristics of mumps viruses circulating in the post vaccine era in Jiangsu province of China. The complete sequences of mumps virus small hydrophobic(SH) gene were amplified and sequenced; coalescent-based Bayesian method was used to perform phylogenetic analysis with BEAST 1.84 software. Commercially available indirect enzyme-linked immune-sorbent IgG assay was used for the quantitative detection of IgG antibody against mumps virus. Our results show that genotype F was the predominant mumps viruses and belonged to indigenous spread, and most of Jiangsu sequences clustered together and formed a monophyly. The prevalence of mumps reached a peak in 2012 and subsequently declined, which presented an obvious different trajectory with virus circulating in other regions of China. The gene diversity of viruses circulating in Jiangsu province was far less than those in China. The antibody prevalence reached 70.42% in the general population during 2018 to 2020. The rising trend of antibody level was also observed. Although mumps antibody prevalence does not reach expected level, mumps virus faces higher pressure in Jiangsu province than the whole of China. To reduce further the prevalence of mumps viruses, two doses of mumps vaccine should be involved into EPI.

Shedding of measles vaccine RNA in children after receiving measles, mumps and rubella vaccination.

BACKGROUND: Measles, mumps, and rubella(MMR) vaccination is critical to measles outbreak responses. However, vaccine reactions and detection of measles vaccine RNA in recently immunized persons may complicate case classification especially in those presenting with another respiratory viral illness. We aim to characterize cases of measles vaccine shedding in recently vaccinated children presenting with respiratory viral symptoms. METHODS: Children who were tested with a multiplex respiratory panel <30 days after receiving MMR were identified. Remnant nasopharyngeal(NP) samples were tested for measles vaccine by PCR. Medical records were reviewed for demographics, presenting symptoms, and test results. RESULTS: From January 2022 to March 2023, 127 NP from children who received MMR were tested. Ninety-six NP were collected after the first dose, of which 33(34.4 %) were positive for vaccine RNA. The median interval between MMR and detection was 11.0 days. Thirty-one NP were collected after the second MMR and 1(3.2 %) was positive; time between the vaccination and detection was 18.9 days. Median cycle threshold(Ct) value of the measles PCR for vaccine shedding was significantly higher than median Ct in children with wild-type infection. CONCLUSION: Shedding of measles vaccine RNA is not uncommon and vaccine RNA can be detected up to 29 days post MMR; the amount of vaccine RNA shedding is low indicated by high Ct values. Clinicians and public health officials should consider performing measles vaccine testing on those testing positive for measles within one month of MMR vaccination, especially if the Ct value is high and definitive epidemiological links are absent.

Worth a Shot: Experience and Lessons From an Unsuccessful Pediatric Immunization Quality Improvement Effort in a Large Health System During the COVID-19 Pandemic.

INTRODUCTION: During the coronavirus disease of 2019 (COVID-19) pandemic, routine childhood immunization rates dropped dramatically across the world, and the Military Health System (MHS) was no exception. In the MHS, which is a large, universally covered, low-to-no-cost health system, the immunization rates with the measles, mumps, and rubella (MMR) vaccine remain below the rate necessary to prevent community transmission of measles. We aimed to improve childhood immunization rates in the MHS with an expansive quality improvement project. MATERIALS AND METHODS: Measles, mumps, and rubella immunization rates served as proxy outcome measures for routine immunization rates tracked by the Center for Disease Control multi-immunization combination measures. The tracked measure was the percentage of 16- to 18-month olds and 6-year olds who had received MMR #1 and MMR #2, respectively. Various countermeasures were implemented throughout the study period, and standard quality improvement analyses informed the effect of countermeasures. RESULTS: By January 2023, the percentage of 16- to 18-month olds and 6-year olds who had received MMR #1 and MMR #2 was 85% and 91%, respectively, with no positive shift in immunization rates despite various countermeasures introduced during the study period. For reference, the MMR immunization rates of commercial health maintenance organization and commercial preferred provider organization for 24-month-old populations were 92% and 90.3%, respectively. On chart review, the most common cause for under-immunization (55%) was vaccine abandonment. MMR #1 rates rose to 92% in 24-month olds. CONCLUSIONS: Measles, mumps, and rubella immunization rates within the MHS remained below commercial health system rates and below public health standards required for herd immunity despite various countermeasures throughout the COVID-19 pandemic. Immunization rates increased with age, suggesting that children within the MHS eventually catch up despite potential barriers.

The impact of temperature, humidity and closing school on the mumps epidemic: a case study in the mainland of China.

BACKGROUND: To control resurging infectious diseases like mumps, it is necessary to resort to effective control and preventive measures. These measures include increasing vaccine coverage, providing the community with advice on how to reduce exposure, and closing schools. To justify such intervention, it is important to understand how well each of these measures helps to limit transmission. METHODS: In this paper, we propose a simple SEILR (susceptible-exposed-symptomatically infectious-asymptomatically infectious-recovered) model by using a novel transmission rate function to incorporate temperature, humidity, and closing school factors. This new transmission rate function allows us to verify the impact of each factor either separately or combined. Using reported mumps cases from 2004 to 2018 in the mainland of China, we perform data fitting and parameter estimation to evaluate the basic reproduction number  R 0 . As a wide range of one-dose measles, mumps, and rubella (MMR) vaccine programs in China started only in 2008, we use different vaccination proportions for the first Stage I period (from 2004 to 2008) and the second Stage II period (from 2009 to 2018). This allows us to verify the importance of higher vaccine coverage with a possible second dose of MMR vaccine. RESULTS: We find that the basic reproduction number  R 0  is generally between 1 and 3. We then use the Akaike Information Criteria to assess the extent to which each of the three factors contributed to the spread of mumps. The findings suggest that the impact of all three factors is substantial, with temperature having the most significant impact, followed by school opening and closing, and finally humidity. CONCLUSION: We conclude that the strategy of increasing vaccine coverage, changing micro-climate (temperature and humidity), and closing schools can greatly reduce mumps transmission.

Immunity against vaccine-preventable diseases among pregnant employees in Germany. A situation analysis before the introduction of the Measles Protection Act.

BACKGROUND: Immunization against vaccine-preventable diseases prior to pregnancy is an important measure of primary prevention both for the mother and the unborn child. We analyzed immunity rates against measles, mumps, rubella, varicella, and pertussis in pregnant employees in Germany prior to significant changes in legal conditions in 2020, to provide a basis of comparison for future research. METHODS: We analyzed occupational-medical routine data in three collectives of pregnant women with an occupational risk of infection in the years 2018 and 2019: 1: hospital staff with regular access to an in-house company physician (n = 148); 2: employees in childcare with regular access to external occupational-health services (n = 139); 3: teachers with no regular access to occupational healthcare (n = 285). Immune status was assessed by a physician based on vaccination certificates, laboratory results, and medical documentation on prior infections. We compared immunity rates against measles, rubella, varicella, and pertussis as well as full immunity against all targeted vaccine-preventable diseases. RESULTS: Altogether, n = 572 pregnant women were included in our study. Of these women, 96.5 % were immune to rubella, 95.8 % to varicella, 88.3 % to measles, 82.7 % to mumps, and 67.8 % to pertussis. Only 56.2 % of the women had full immunity against all targeted vaccine-preventable diseases. Collective 1 showed the highest immunity rates against measles and pertussis as well as the highest rate of full immunity against all targeted vaccine-preventable diseases. The immunity rates against rubella and varicella did not differ significantly between the collectives. With the exception of rubella, the lowest immunity rates during pregnancy were found in Collective 3. CONCLUSION: We found pregnancy-relevant immunity gaps in all our study groups with significant differences between the collectives. Considering the potentially devastating consequences of infections during pregnancy, all medical professionals and health-policy makers should be involved in an increased effort to improve vaccination rates prior to pregnancy.

Mumps in Poland in 2021. / Swinka w Polsce w 2021 roku.

INTRODUCTION: Mumps is a contagious viral disease occurring mainly in children, the source of infection being the sick/infected person. Since 2003, vaccination against mumps has been mandatory in Poland, performed according to a two-dose schedule. As part of the Public Health Immunization Program (PSO), the MMR combination vaccine (against measles, mumps and rubella) is used for the entire population of children. OBJECTIVES: The aim of this study was to evaluate epidemiological indicators of mumps in Poland in 2021 compared to previous years, taking into account the impact of the COVID-19 pandemic. MATERIAL AND METHODS: The analysis of the epidemiological situation of mumps in Poland in 2021 was based on the interpretation of data from the bulletin , "Infectious diseases and poisonings in Poland in 2021" and , "Immunization in Poland in 2021". RESULTS: 484 cases of mumps were registered in Poland in 2021. The total incidence was 1.3 per 100,000 residents, which was lower than in 2020. The highest incidence of 1.8 per 100,000 residents was registered in Pomorskie Province, and the lowest incidence of 0.7 in Lower Silesia Province. The highest incidence (6.4/100 thousand) was recorded in children aged 0-4 and 5-9. The incidence rate for men (1.4/100,000) was higher than for women (1.1). In 2021, there were 9 patients hospitalized due to mumps, this was more than in 2020. CONCLUSIONS: The decrease in the number of cases of mumps in 2021 remained related to the ongoing pandemic - the restrictions introduced during the pandemic period led to a decrease in the number of cases not only of COVID-19, but also of other diseases spread by the droplet route, including mumps. The number of registered cases based on the reports of diagnosing physicians may be underestimating the actual number of cases due to the continued difficult access of patients to primary care physicians.

Measles, mumps, and rubella vaccination coverage: an ecological study of primary health care and socio-economic factors in Catalonia, Spain.

This study examined the association of socio-economic factors and the structure of primary care centres (PCCs) with measles, mumps, and rubella (MMR) vaccination coverage among the 8-year-old population in Catalonia, Spain. We conducted an ecological study to retrospectively assess the MMR vaccination-recorded status of children born in 2012, using public health data extracted in December 2020. For each of 300 PCCs serving 70,498 children, we calculated vaccination coverage rates from electronic health records and linked these rates to a composite deprivation index corresponding to the territory served by each PCC. We identified a relationship between unfavourable socio-economic factors and higher recorded vaccination coverage. On average, directly managed PCCs had higher vaccination coverage rates than indirectly managed PCCs. Greater utilisation of primary care services by the population was also associated with higher vaccination coverage rates. Further research is needed to generate knowledge valuable for informing more equitable child-vaccination service delivery models.

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.

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.

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.

Estimation of the infection attack rate of mumps in an outbreak among college students using paired serology.

Mumps virus is a highly transmissible pathogen that is effectively controlled in countries with high vaccination coverage. Nevertheless, outbreaks have occurred worldwide over the past decades in vaccinated populations. Here we analyse an outbreak of mumps virus genotype G among college students in the Netherlands over the period 2009-2012 using paired serological data. To identify infections in the presence of preexisting antibodies we compared mumps specific serum IgG concentrations in two consecutive samples (n=746), whereby the first sample was taken when students started their study prior to the outbreaks, and the second sample was taken 2-5 years later. We fit a binary mixture model to the data. The two mixing distributions represent uninfected and infected classes. Throughout we assume that the infection probability increases with the ratio of antibody concentrations of the second to first sample. The estimated infection attack rate in this study is higher than reported earlier (0.095 versus 0.042). The analyses yield probabilistic classifications of participants, which are mostly quite precise owing to the high intraclass correlation of samples in uninfected participants (0.85, 95%CrI: 0.82-0.87). The estimated probability of infection increases with decreasing antibody concentration in the pre-outbreak sample, such that the probability of infection is 0.12 (95%CrI: 0.10-0.13) for the lowest quartile of the pre-outbreak samples and 0.056 (95%CrI: 0.044-0.068) for the highest quartile. We discuss the implications of these insights for the design of booster vaccination strategies.

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.

The immune status of migrant populations in Europe and implications for vaccine-preventable disease control: a systematic review and meta-analysis.

BACKGROUND: Ensuring vaccination coverage reaches established herd immunity thresholds (HITs) is the cornerstone of any vaccination programme. Diverse migrant populations in European countries have been associated with cases of vaccine-preventable diseases (VPDs) and outbreaks, yet it is not clear to what extent they are an under-immunized group. METHODS: We did a systematic review and meta-analysis to synthesize peer-reviewed published primary research reporting data on the immune status of migrants in EU/EEA countries, the UK and Switzerland, calculating their pooled immunity coverage for measles, mumps, rubella and diphtheria using random-effects models. We searched on Web of Science, Embase, Global Health and MEDLINE (1 January 2000 to 10 June 2022), with no language restrictions. The protocol is registered with PROSPERO (CRD42018103666). FINDINGS: Of 1103 abstracts screened, 62 met eligibility criteria, of which 39 were included in the meta-analysis. The meta-analysis included 75 089 migrants, predominantly from outside Europe. Pooled immunity coverage among migrant populations was well below the recommended HIT for diphtheria (n = 7, 57.4% [95% confidence interval (CI): 43.1-71.7%] I2 = 99% vs HIT 83-86%), measles (n = 21, 83.7% [95% CI: 79.2-88.2] I2 = 99% vs HIT 93-95%) and mumps (n = 8, 67.1% [95% CI: 50.6-83.6] I2 = 99% vs HIT 88-93%) and midway for rubella (n = 29, 85.6% [95% CI: 83.1-88.1%] I2 = 99% vs HIT 83-94%), with high heterogeneity across studies. INTERPRETATION: Migrants in Europe are an under-immunized group for a range of important VPDs, with this study reinforcing the importance of engaging children, adolescents and adults in 'catch-up' vaccination initiatives on arrival for vaccines, doses and boosters they may have missed in their home countries. Co-designing strategies to strengthen catch-up vaccination across the life course in under-immunized groups is an important next step if we are to meet European and global targets for VPD elimination and control and ensure vaccine equity.