Waning immunity of one-dose measles-mumps-rubella vaccine to mumps in children from kindergarten to early school age: a prospective study

Phase III, open-label, single-arm study of a new MMR vaccine (JVC-001); measles AIK-C, mumps RIT 4385, rubella Takahashi, as a second vaccine dose in healthy Japanese children aged 5-6 years

PURPOSE

This Phase III, multicenter, open-label, single-arm study evaluated the safety and immunogenicity of the measles-mumps-rubella (MMR) combined vaccine, JVC-001, as a second MMR vaccination.

METHODS

Healthy Japanese children aged 5-6 years received a single dose of JVC-001 following a first measles, mumps, and rubella vaccination (measles-rubella bivalent and mumps monovalent vaccine [Hoshino or Torii strain] or JVC-001) or the MMR vaccine received between ages 1 to <4 years. Immunogenicity was evaluated using antibody titers before and after vaccination (Day 1/Day 43). The primary endpoint was the seroprotection rate of antibody titers against each virus; geometric mean titer (GMT) was also evaluated. Adverse events (AEs) and adverse drug reactions (ADRs) were monitored.

RESULTS

One-hundred participants completed the study. The seroprotection rate of antibody titers against measles, rubella, and mumps virus (genotype D) were 100.0% (95% confidence interval [CI] 96.4%, 100.0%), 100.0% (95% CI 96.4%, 100.0%), and 100.0% (95% CI 96.3%, 100.0%), respectively. GMT (fold) increases (Day 1 to Day 43) were 16.0 to 55.7 for measles virus, 35.5 to 99.0 for rubella virus, and 25.7 to 89.5 for mumps virus (genotype D). Solicited ADRs occurred in 40.0% of participants (injection site, 34.0%; systemic, 13.0%).

CONCLUSIONS

The second MMR vaccination with JVC-001 demonstrated sufficient antibody coverage against all three viruses; the safety profile was tolerable.

CLINICAL TRIAL REGISTRATION

jRCT2080225022.

Mumps-specific antibody persistence in children aged 3-7 years immunized with two doses of mumps-containing vaccines: A prospective cohort study in Jiangsu Province, China

Mumps reemergence has been reported in developed countries with high levels of two-dose mumps-containing vaccine (MuCV) coverage. The effectiveness of the two-dose MuCV may be compromised by limitations in the persistence of immunity. This prospective cohort study evaluated the persistence of immunity of a two-dose MuCV in children aged 3-7 years from 2015 to 2020. Persistence of antibody to mumps, determined as the geometric mean antibody concentration (GMC), and seropositivity were analyzed for both repeated measurements from three follow-ups and on each cross-section, respectively. A total of 105 eligible subjects were recruited. Their overall seropositivity rate was relatively high and stable (92.4%-84.8%), while the overall GMC decreased from 547.6 U/ml to 333.3 U/ml. Analysis of waning immunity in 91 participants showed a significant and consistent downward trend for GMC, which differed significantly in boys and girls. The overall seropositivity rate decreased slightly from 2015 (95.6%) to 2016 (92.3%) but both were significantly higher than in 2018 (84.6%). The rates in girls remained stable, while those in boys declined to 75% in 2018. The seropositivity rate of the cross-section level decreased from 95.4% to 86.4% in 4 years. Although two-dose MuCV may result in a high level of immunity, antibody concentrations decay over 2 years after the second dose. Children with waning immunity after receiving two doses, especially boys, require further surveillance at 4 years and later to avoid future mumps epidemics.Clinical trial registration: NCT02901990.

A Multi-Age-Group Interrupted Time-Series Study for Evaluating the Effectiveness of National Expanded Program on Immunization on Mumps

The national Expanded Program on Immunization (EPI) in China has covered vaccines for measles, mumps, and rubella, among children aged 18–24 months since September 2008. However, no previous studies have quantified the effectiveness of the EPI on mumps incidence. There are methodological challenges in assessing the effect of an intervention that targets a subpopulation but finally influences the whole population. In this study, monthly data on mumps incidence were collected in Guangzhou, China, during 2005–2019. We proposed a multi-age-group interrupted time-series design, setting the starting time of exerting effect separately for 14 different age groups. A mixed-effects quasi-Poisson regression was applied to analyze the effectiveness of the EPI on mumps incidence, after controlling for long-term and seasonal trends, and meteorological factors. The model also accounted for the first-order autocorrelation within each age group. Between-age-group correlations were expressed using the contact matrix of age groups. We found that 70,682 mumps cases were reported during 2005–2019, with an annual incidence rate of 37.91 cases per 100,000 population. The effect of EPI strengthened over time, resulting in a decrease in the incidence of mumps by 16.6% (EPI-associated excess risk% = −16.6%, 95% CI: −27.0% to −4.7%) in September 2009 to 40.1% (EPI-associated excess risk% = −40.1%, 95% CI: −46.1% to −33.3%) in September 2019. A reverse U-shape pattern was found in age-specific effect estimates, with the largest reduction of 129 cases per 100,000 population (95% CI: 14 to 1173) in those aged 4–5 years. The EPI is effective in reducing the mumps incidence in Guangzhou. The proposed modeling strategy can be applied for simultaneous assessment of the effectiveness of public health interventions across different age groups, with adequate adjustment for within- and between-group correlations.

Estimating the Transmissibility of Mumps: A Modelling Study in Wuhan City, China

Despite the adoption of a national immunization program in China, the incidence of mumps remains high. This study aimed to describe the epidemiological characteristics, including the time, region, occupation, and age, of mumps in Wuhan from 2005 to 2018 and to evaluate its transmissibility. In this study, the susceptible-exposed-infectious-asymptomatic-recovered (SEIAR) model fitted the actual incidence data of mumps. The effective reproduction number (R t ) was used to evaluate and compare the transmission capacity in different areas. From 2005 to 2018, there were 36,415 cases. The incidence of mumps was highest among people aged 5-10 years (460.02 per 100,000). The SEIAR model fitted the reported mumps data well (P < 0.01). The median transmissibility (R t ) was 1.04 (range = 0-2.50). There were two peak spreads every year (from March to May and from October to December). The R t peak always appeared in the first 2 months of the peak incidence rate. The peak time of the epidemic spread of mumps was 1-2 months earlier than the peak incidence rate. The prevention and control measures of vaccination for children aged 5-10 years should be taken before the peak transmission capacity each year, 2 months before the peak of the outbreak, to reduce the spread of mumps.

Loss of protective immunity of two-dose mumps-containing vaccine over time: concerns with the new strategy of the mumps immunization program in China

Background: Currently, children aged 6-9 years have the highest incidence rate of mumps in China. Although China has introduced a two-dose schedule of measles-mumps-rubella vaccine into routine immunization (at 8 months and 18 months), the incidence rate of mumps in high-risk populations might not decrease due to waning immunity. Here we report a mumps outbreak supporting this hypothesis.Methods: The descriptive epidemiological method was used to summarize the overall characteristics of the course of the outbreak. We conducted a retrospective cohort study to evaluate the vaccine effectiveness (VE) of mumps-containing vaccine (MuCV).Results: A total of 78 cases were identified during the outbreak and the estimated vaccination coverage was 84.7%. Of 454 vaccinated students, 335 (73.8%) had received one-dose MuCV, 93 (20.5%) two-dose, and 26 (5.7%) three-dose. The VEs for both the one-dose (-17.0%, 95%CI: -120.3-38.2%) and two-dose groups (-10.0%, 95%CI: -138.0-48.8%) were not performed well, whereas the VE for the three-dose group was 100%. However, we found that the overall VE was 74.2% (95% CI: 9.7-92.6%) for students vaccinated within 5 years. We also observed that there was a broadly linear increase in mumps infection risk in both one-dose and two-dose group when the time since last dose vaccination was more than 5 years.Conclusions: The overall VE for both one-dose and two-dose MuCV was discouraging, but it appeared to be moderately effective within 5 years after vaccination. Further surveillance and seroepidemiological data are needed to understand the impact of the new vaccination strategy on mumps in China.

Waning immunity and potential asymptomatic infection in 3-7 years old children who received one dose of measles-mumps-rubella vaccine: A 4-year prospective study

BACKGROUND

Mumps outbreaks in adolescents who received two doses of measles-mumps-rubella vaccine (MMR) during childhood have been reported worldwide. In China, one dose of MMR administered in children aged among 18-24 months has a limited effect on the mumps epidemic. There are limited prospective studies evaluating the mumps immunity profile of children aged 3-7 years who received one dose of MMR. This study aimed to describe mumps immunity profile over a span of 4-years in kindergarten and primary school children.

METHODS

An observational, prospective study on one-dose MMR in children aged 3-7 years who underwent blood sample collection in 2015, 2016, and 2018 was conducted from 2015 to 2018. The seropositivity and geometric mean concentration of mumps IgG antibodies over time were analyzed.

RESULTS

A total of 3346 eligible children aged 3-7 years who underwent three rounds of blood sample collection were included. The overall seropositivity (79.6%) in 2015 was significantly higher than those recorded in 2016 (73.1%) and 2018 (71.4%). Approximately 11.6-15.9% of the participants were seropositive for mumps in 2015, and converted to negative in 2016. Meanwhile, 11.1-14.6% of the participants were seropositive for mumps in 2016, and the results converted to negative in 2018. Over 6.1-7.4% of the participants had asymptomatic infection from 2015 to 2016, while 9.0-9.9% of the participants were infected without clinical symptoms from 2016 to 2018.

CONCLUSIONS

Kindergarten and primary school children who only received one dose of MMR were at higher risk of developing mumps. Waning immunity, seronegative conversion, and asymptomatic infection coexist in children who received one dose MMR. Determining the optimal age for administering the second dose of MMR in children should be prioritized to improve the control and prevention of mumps in China.

Epidemiological and Phylogenetic Analysis of Mumps Virus Isolated from 2016 to 2019 in Henan Province, China

Routine vaccination has proven to be highly effective in reducing the incidence of mumps. However, sporadic cases and/or mumps outbreaks have been reported in children and adolescents younger than 15 years of age, particularly among those aged 5-9 years. To explore the characteristics of such outbreaks in the Henan Province, clinical data of patients infected with mumps virus (MuV) were collected, and the isolated strains were phylogenetically analyzed. Of the total 426 samples analyzed, MuV RNA targeting the small hydrophobic (SH) gene was detected in 153 samples. MuV-positive cases in age groups <5 years, 5-9 years, 10-15 years, 16-19 years, and ≥20 years accounted for 1%, 17%, 12%, 2%, and 4% of the total number of cases, respectively. Phylogenetic analysis based on the SH gene sequences indicated that all of the isolated strains were of genotype F, and isolates in the same subcluster and with identical SH gene sequences tended to be derived from the same community or municipalities when analyzed alongside epidemiological data. In conclusion, the incidence of mumps in the Henan Province was high. The data provided in this study might promote further research in the clarification of the specific causes of mumps outbreaks, which can facilitate the implementation of effective prevention and control measures.

Patient Delay in Hospital Visiting and the Weekend Effect of Surveillance Report on Hand-Foot-and-Mouth Disease and Epidemic Parotitis in Hanzhong City, China

Background

We aimed at investigating the prevalence and associated factors of patient delay in hospital visiting and weekend effect of disease surveillance on hand-foot-and-mouth disease and epidemic parotitis/mumps.

Methods

Daily report data on hand-foot-and-mouth disease and epidemic parotitis cases between January 1, 2014, and December 31, 2017, in Hanzhong, Shaanxi, China, were collected. The patient delay in hospital visiting was defined by the date difference between disease onset and patient's visit to hospital. Differences of delayed durations and percentages were compared by using nonparametric or χ² tests across gender, age, occupation, disease classification, epidemic and nonepidemic seasons, and years of disease onset. Additionally, to determine whether there existed a weekend effect of disease surveillance, the mean cases reported on weekdays and weekends were also compared.

Results

A total of 14,814 patients with hand-foot-and-mouth disease and 4013 with epidemic parotitis were recorded, respectively. We found that 43.1% of the hand-foot-and-mouth disease and 36.5% of the epidemic parotitis patients had delayed visiting to hospital. All patients were reported through the online surveillance system on the day of visiting hospital. The percentage of delayed visiting to hospital differed significantly by years and epidemic and nonepidemic seasons and between children in and not in childcare center (all p values <0.05). In addition, the reported numbers of both diseases fluctuated on weekdays but obviously decreased on weekends regardless of the epidemic or nonepidemic seasons.

Conclusions

The reported cases of HFMD and epidemic parotitis had an obvious weekend effect, with an increasing tendency of cases delaying in hospital visiting over the recent years in Hanzhong, China. Parents and caregivers rather than health systems should be primarily targeted for the prevention and control of infectious diseases and their local outbreaks such as community-based education on the second-dose vaccination of mumps and/or hand hygiene.

Application of a fast and cost-effective 'three-in-one' MMR ELISA as a tool for surveying anti-MMR humoral immunity: the Hungarian experience

In Hungary, between February 2017 and July 2019, 70 confirmed measles cases were reported, raising questions about the adequacy of population-level immunity. Although the assumed vaccination coverage is ≥99%, in a recent study, we detected potential gaps in the anti-measles humoral immunity. In Hungary, according to a decree by the Ministry of Public Welfare, beginning from 2021, the healthcare provider should conduct a serosurvey of anti-measles protection levels of healthcare professionals. To facilitate the compliance with this requirement, we developed a quick 'three-in-one' or 'triple' MMR (measles, mumps and rubella) indirect ELISA (IgG); an assay format that is currently not available commercially. High throughput applicability of the 'three-in-one' ELISA was verified using 1736 sera from routine laboratory residual samples, using an automated platform (Siemens BEP 2000 Advance). Assay verification was performed by comparing the full antigen repertoire-based 'target' assay with in-house 'control' assays using recombinant viral antigen coatings, and by validated commercially available kits. Indirect immunofluorescence was used as an independent reference method. Data were analysed using OriginLab, IBM SPSS, RStudio and MedCalc. In case of measles, we combined our current results with previously published data (Ntotal measles = 3523). Evaluation of anti-mumps and anti-rubella humoral antibody levels was based on the measurement of 1736 samples. The lowest anti-measles seropositivity (79.3%) was detected in sera of individuals vaccinated between 1978 and 1987. Considering the antigen-specific seropositivity ratios of all samples measured, anti-measles, -mumps and -rubella IgG antibody titres were adequate in 89.84%, 91.82% and 92.28%, respectively. Based on the virus-specific herd immunity threshold (HIT) values (HITMeasles = 92-95%, HITMumps = 75-86%, HITRubella = 83-86), it can be stated that regarding anti-measles immunity, certain age clusters of the population may have inadequate levels of humoral immunity. Despite the potential gaps in herd immunity, the use of MMR vaccine remains an effective and low-cost approach for the prevention of measles, mumps and rubella infections.

Measles, rubella, mumps and Toxoplasma gondii antibodies in saliva of vaccinated students of schools and universities in São Paulo City, Brazil

Introduction

Vaccines are well-established public health interventions with major impact on the prevalence of infectious diseases, but outbreaks are occurring frequently due to primary and secondary failures, despite high coverage. Surveillance of efficacy and duration of induced immunity is a difficult task as it requires invasive blood sampling in children and teenagers. Saliva can be an acceptable alternative source of IgG to assess vaccine efficacy and toxoplasmosis incidence. We investigated IgG response for measles, mumps, rubella, and T. gondii in saliva samples of vaccinated young people.

Methods

Saliva was collected from 249 public schools students from São Paulo, Brazil, aged 7 to 13 years old, during an interactive exhibition on hygiene. We used S. aureus protein A solid phase capture assay for IgG reactive to biotinylated purified proteins. Paired saliva and serum (47) were tested from young adults with serum evidence of T. gondii infection and from negative children less than 12 month old for standardization. Reproducibility was greater than 98% and sensitivity and specificity of the saliva assays were greater than 95%, as well as the concordance of paired saliva and serum samples.

Results

Saliva from high school students showed a prevalence of 8.5% (95% CI: 5.0–11.9%) for anti T. gondii IgG; 96.8% (94.6–99%) of anti-measles IgG; 59.1% (53–65%) of anti-rubella IgG, and 57.5% (51.3–63.6%) of anti-mumps IgG.

Discussion

The prevalence of antibodies against mumps and rubella after 6–8 years of vaccination was lower than against measles among students. The findings of this study demonstrate the feasibility of saliva sampling for follow-up of vaccine immune status in teenagers. This useful approach allows for IgG detection for vaccine control or epidemiological studies.

Seroprevalence and durability of rubella virus antibodies in a highly immunized population

BACKGROUND

Although the administration of the measles-mumps-rubella (MMR) vaccine has been widespread in the United States for decades, gaps in vaccine coverage still persist for various reasons. The maintenance of herd immunity against rubella virus (RV) is important to controlling the spread and resurgence of rubella and congenital rubella syndrome.

METHODS

In this study, we sought to assess the seroprevalence of RV-specific antibodies in an adult population from a defined geographic area in Olmsted County, MN, and the surrounding municipalities, with relatively high vaccine coverage and no documented evidence of circulating RV in the past 24 years. Rubella-specific IgG antibodies were measured by ELISA in a large set of serum samples (n = 1393) obtained from the Mayo Clinic Biobank. This cohort was 80.2% female and ranged from 20 to 44 years of age.

RESULTS

In total, 97.8% of subjects were seropositive for rubella-specific IgG antibodies, with a median titer of 40.56 IU/mL, suggesting a high degree of immunization; however, 2.2% of subjects were found to be seronegative. Interestingly, 25.1% of subjects were seropositive but had titers lower than 25 IU/mL, indicating either a population of low responders or individuals that could potentially be at risk of waning immunity. No significant associations or differences were found between RV-specific titers and demographic variables such as age, sex, or body mass index (BMI).

CONCLUSIONS

A high rate of seropositivity for rubella was found among this young adult cohort, but a significant percent of the cohort had lower titers that may indicate poor initial vaccine response and potential risk if their antibody titers decline.

Application of a mixture model to assess the effect of measles-mumps-rubella vaccine on the mumps epidemic in children from kindergarten to early school age in Jiangsu Province, China

A single dose of the measles-mumps-rubella (MMR) vaccine has been applied in routine immunizations for children in China; however, the Immunoglobulin G (IgG) antibody level of mumps in children from kindergarten to early school age with MMR vaccine immunization history has not been elucidated. This study aimed to describe the immunity profile of children from kindergarten to early school age to identify the susceptible population. In Jiangsu Province, a cross-sectional survey of 4- to 8-year-old children who were vaccinated with at least one dose of MMR vaccine was conducted. IgG antibody results were analyzed by employing both the Enzyme-Linked Immunosorbent Assay (ELISA) cutoff values and the mixture model. A total of 7436 eligible subjects were enrolled: 3386 subjects were in kindergarten, and 4450 were in primary school. The overall seroprevalence (75.4%, 95% CI: 74.4%-76.4%) and Geometric mean concentration (GMC, 201.4U/ml, 95% CI: 194.1-209.4) of mumps antibodies in 2016 were low. The seroprevalence of children in kindergarten (78.1%, 95% CI: 76.6%-79.4%) was significantly higher than that of children in primary school (73.2%, 95% CI: 71.2%-74.6%). The GMC was negatively correlated with the time of inoculation (F = 32.17, P = 0.002). The mixture model enables a more comprehensive understanding of serological results by investigating four levels of antibody response, suggesting that there is a small fraction of the population with waning immunity. Children in kindergarten and primary school whom had received one dose of MMR vaccine were at a higher risk of mumps infection, particularly the 7-year-old group in the central region. Therefore, the single-dose MMR vaccine schedule has a limited impact on mumps control and prevention, and a two-dose MMR vaccine schedule should be introduced.