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.

Three SARS-CoV-2 spike protein variants delivered intranasally by measles and mumps vaccines are broadly protective.

As the new SARS-CoV-2 Omicron variants and subvariants emerge, there is an urgency to develop intranasal, broadly protective vaccines. Here, we developed highly efficacious, intranasal trivalent SARS-CoV-2 vaccine candidates (TVC) based on three components of the MMR vaccine: measles virus (MeV), mumps virus (MuV) Jeryl Lynn (JL1) strain, and MuV JL2 strain. Specifically, MeV, MuV-JL1, and MuV-JL2 vaccine strains, each expressing prefusion spike (preS-6P) from a different variant of concern (VoC), were combined to generate TVCs. Intranasal immunization of IFNAR1-/- mice and female hamsters with TVCs generated high levels of S-specific serum IgG antibodies, broad neutralizing antibodies, and mucosal IgA antibodies as well as tissue-resident memory T cells in the lungs. The immunized female hamsters were protected from challenge with SARS-CoV-2 original WA1, B.1.617.2, and B.1.1.529 strains. The preexisting MeV and MuV immunity does not significantly interfere with the efficacy of TVC. Thus, the trivalent platform is a promising next-generation SARS-CoV-2 vaccine candidate.

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.

Measles outbreak associated with a preschool setting among partially vaccinated children in the Tel Aviv District, Israel, October 2023.

In October 2023, the Tel Aviv District was notified of ten cases of measles. The outbreak initiated in a preschool with high vaccination coverage with one dose of MMR vaccine. Serological testing was available for eight patients (six children and two adults). Among the six children vaccinated with one dose of MMR vaccine, primary vaccine failure was demonstrated. Among the adults, secondary vaccine failure was confirmed. The outbreak was successfully contained due to a combination of factors, notably its occurrence within a population characterized by high vaccination coverage in Tel Aviv, during a period of restricted public interactions due to the prevailing state of war in the country. Despite challenging wartime conditions, effective prophylactic measures were promptly executed, encompassing a 2-dose MMR vaccination schedule for close contacts and the broader community of children in the TA district, successfully curbing the outbreak and preventing widespread infections.

Phase 3 Safety and Immunogenicity Study of a Three-dose Series of Twenty-valent Pneumococcal Conjugate Vaccine in Healthy Infants and Toddlers.

BACKGROUND: Global pediatric immunization programs with pneumococcal conjugate vaccines (PCVs) have reduced vaccine-type pneumococcal disease, but a substantial disease burden of non-PCV serotypes remains. METHODS: This phase 3, randomized (1:1), double-blind study evaluated safety and immunogenicity of 20-valent PCV (PCV20) relative to 13-valent PCV (PCV13) in healthy infants. Participants received 2 infant doses and a toddler dose of PCV20 or PCV13, with diphtheria-tetanus-acellular pertussis combination vaccine at all doses and measles, mumps, rubella and varicella vaccines at the toddler dose. Primary pneumococcal immunogenicity objectives were to demonstrate noninferiority (NI) of PCV20 to PCV13 for immunoglobulin G geometric mean concentrations after infant and toddler doses and percentages of participants with predefined serotype-specific immunoglobulin G concentrations after infant doses. Safety endpoints included local reactions, systemic events and adverse events. RESULTS: Overall, 1204 participants were vaccinated (PCV20, n = 601; PCV13, n = 603). One month after the toddler dose, 19/20 serotypes met NI for immunoglobulin G geometric mean concentrations; serotype 6B narrowly missed NI [PCV20/PCV13 geometric mean ratio: 0.57 (2-sided 95% confidence interval: 0.48-0.67); NI criterion: lower 2-sided 95% confidence interval >0.5]. Sixteen/twenty serotypes met NI for ≥1 primary objective after 2 infant doses. PCV20 induced robust opsonophagocytic activity, and boosting responses were observed for all vaccine serotypes, including those missing statistical NI. The safety/tolerability profile of PCV20 was like that of PCV13. CONCLUSIONS: PCV20 3-dose series in infants was safe and elicited robust immune responses. Based on these results and PCV13 experience, PCV20 3-dose series is expected to be protective for all 20 vaccine serotypes. NCT04546425.

Efficacy of Intralesional Candida Antigen Versus Measles, Mumps, and Rubella Vaccine Versus Topical Podophyllin in Treatment of Resistant Genital Warts.

BACKGROUND: No single treatment is ideal for genital warts with high rate of resistance using conventional modalities as topical podophyllin; however, several intralesional immunotherapies are being tested nowadays, with variable results. In this study, we compared the safety and efficacy of treating resistant and recurrent genital warts by 2 intralesional immunotherapies [Candida antigen and measles, mumps, and rubella (MMR) vaccine] and compared them with topical podophyllin. PATIENTS/METHODS: A total of 45 patients with resistant or recurrent genital warts were enrolled in this study. Size and number of warts were detected in each patient, patients were divided into 3 groups. Group A injected with intralesional Candida antigen. Group B with intralesional MMR vaccine. Group C were treated with topical 25% podophyllin. Patients received a session every 2 weeks for 3 treatment sessions. RESULTS: With regard to the reduction in size and number of all warts, the best response was obtained in Candida antigen group where 46.7% showed complete clearance and 40% showed partial response followed by MMR group and the last was the podophyllin group, with no significant difference between them. Complete clearance of mother warts was noticed in 86.7% of Candida group, 53.3% in MMR group, and last 40% in podophyllin group, with a significantly better response in the Candida group (P = .027). CONCLUSION: Both intralesional Candida antigen and MMR vaccine are simple, safe, and effective treatment options with comparable results and better response than topical podophyllin.

Evaluation of Children with Cow's Milk Allergy Who Received Measles or Measles, Mumps, and Rubella Vaccines Containing Alpha-Lactalbumin.

Objective: Cases of cow's milk allergy (CMA) who reacted to measles or measles, mumps, and rubella (MMR) vaccines containing alpha-lactalbumin have been reported. The purpose of this study was to assess patients with CMA who received measles or MMR vaccines containing alpha-lactalbumin, as well as the characteristics of those who developed reactions to these vaccines. Study Design: Patients followed up in the allergy clinic for CMA and who received measles or MMR vaccines containing alpha-lactalbumin at 9 or 12 months of age were included in the study, and their characteristics were analyzed retrospectively from the hospital registry system. Results: Forty-nine patients were included in the study. Six patients received the measles vaccine, whereas 43 patients received the MMR vaccine containing alpha-lactalbumin. Vaccine skin tests were performed on these 6 patients. One patient had a positive intradermal test, so an alternative vaccine not containing alpha-lactalbumin was administered. The other 5 patients were vaccinated, and no reaction was observed. Anaphylaxis was observed in 3 of 43 patients who received the MMR vaccine containing alpha-lactalbumin. In all of these patients, the first reaction to dairy products was anaphylaxis. In 2 of those patients, cow's milk-specific IgE (spIgE) levels were >100 kU/L, and alpha-lactalbumin-spIgE levels were also high at 97 and 90 kU/L. The third patient's cow's milk-spIgE level was 15.9 kU/L, whereas the alpha-lactalbumin-spIgE level was 0.04 kU/L. Conclusion: Especially in patients with an initial reaction of anaphylaxis to dairy products and high cow's milk-spIgE levels, the risk of reaction is high with the MMR vaccine.

Vacina tríplice viral: saiba quem pode se imunizar

Após a campanha de vacinação para a proteção das crianças e profissionais de saúde contra o sarampo, a vacina tríplice viral segue disponível nas unidades de saúde e faz parte do Calendário Nacional de Vacinação.

A highly efficacious live attenuated mumps virus-based SARS-CoV-2 vaccine candidate expressing a six-proline stabilized prefusion spike.

With the rapid increase in SARS-CoV-2 cases in children, a safe and effective vaccine for this population is urgently needed. The MMR (measles/mumps/rubella) vaccine has been one of the safest and most effective human vaccines used in infants and children since the 1960s. Here, we developed live attenuated recombinant mumps virus (rMuV)-based SARS-CoV-2 vaccine candidates using the MuV Jeryl Lynn (JL2) vaccine strain backbone. The soluble prefusion SARS-CoV-2 spike protein (preS) gene, stablized by two prolines (preS-2P) or six prolines (preS-6P), was inserted into the MuV genome at the P-M or F-SH gene junctions in the MuV genome. preS-6P was more efficiently expressed than preS-2P, and preS-6P expression from the P-M gene junction was more efficient than from the F-SH gene junction. In mice, the rMuV-preS-6P vaccine was more immunogenic than the rMuV-preS-2P vaccine, eliciting stronger neutralizing antibodies and mucosal immunity. Sera raised in response to the rMuV-preS-6P vaccine neutralized SARS-CoV-2 variants of concern, including the Delta variant equivalently. Intranasal and/or subcutaneous immunization of IFNAR1-/- mice and golden Syrian hamsters with the rMuV-preS-6P vaccine induced high levels of neutralizing antibodies, mucosal immunoglobulin A antibody, and T cell immune responses, and were completely protected from challenge by both SARS-CoV-2 USA-WA1/2020 and Delta variants. Therefore, rMuV-preS-6P is a highly promising COVID-19 vaccine candidate, warranting further development as a tetravalent MMR vaccine, which may include protection against SARS-CoV-2.

A method for estimating the impact of new vaccine technologies on vaccination coverage rates.

Vaccines are one of the most cost-effective tools for improving human health and well-being. The impact of a vaccine on population health is partly determined by its coverage rate, the proportion of eligible individuals vaccinated. Coverage rate is a function of the vaccine presentation and the population in which that presentation is deployed. This population includes not only the individuals vaccinated, but also the logistics and healthcare systems responsible for vaccine delivery. Because vaccine coverage rates remain below targets in many settings, vaccine manufacturers and purchasers have a shared interest in better understanding the relationship between vaccine presentation, population characteristics, and coverage rate. While there have been some efforts to describe this relationship, existing research and tools are limited in their ability to quantify coverage rate changes across a broad set of antigens, vaccine presentations, and geographies. In this article, we present a method for estimating the impact of improved vaccine technologies on vaccination coverage rates. It is designed for use with low- and middle-income country vaccination programs. This method uses publicly available data and simple calculations based on probability theory to generate coverage rate values. We first present the conceptual framework and mathematical approach. Using a Microsoft Excel-based implementation, we then apply the method to a vaccine technology in early-stage development: micro-array patch for a measles-rubella vaccine (MR-MAP). Example outputs indicate that a complete switch from the current subcutaneous presentation to MR-MAP in the 73 countries ever eligible for Gavi support would increase overall vaccination coverage by 3.0-4.9 percentage points depending on the final characteristics of the MR-MAP. This change equates to an additional 2.6-4.2 million children vaccinated per year. Our method can be readily extended to other antigens and vaccine technologies to provide quick, low-cost estimates of coverage impact. As vaccine manufacturers and purchasers face increasingly complex decisions, such estimates could facilitate objective comparisons between options and help these decision makers obtain the most value for money.

Mumps virus-specific immune response outcomes and sex-based differences in a cohort of healthy adolescents.

Despite high levels of MMR-II usage in the US, mumps outbreaks continue to occur. Evidence suggests that mumps vaccine-induced humoral immunity wanes over time. Relatively few studies have examined cell-mediated immunity or reported on sex-based differences. To better understand sex-based differences in the immune response to mumps vaccine, we measured neutralizing antibody titers and mumps-specific cytokine/chemokine responses in a cohort of 748 adolescents and young adults after two doses of MMR vaccine. We observed significantly higher neutralizing antibody titers in females than in males (120.8 IU/mL, 98.7 IU/mL, p = 0.038) but significantly higher secretion levels of MIP-1α, MIP-1ß, TNFα, IL-6, IFNγ, and IL-1ß in males compared to females. These data demonstrate that sex influences mumps-specific humoral and cell-mediated immune response outcomes, a phenomenon that should be considered during efforts to improve vaccines and prevent future outbreaks.

The Childhood Vaccination Schedule and the Lack of Association With Type 1 Diabetes.

OBJECTIVES: Safety studies assessing the association between the entire recommended childhood immunization schedule and autoimmune diseases, such as type 1 diabetes mellitus (T1DM), are lacking. To examine the association between the recommended immunization schedule and T1DM, we conducted a retrospective cohort study of children born between 2004 and 2014 in 8 US health care organizations that participate in the Vaccine Safety Datalink. METHODS: Three measures of the immunization schedule were assessed: average days undervaccinated (ADU), cumulative antigen exposure, and cumulative aluminum exposure. T1DM incidence was identified by International Classification of Disease codes. Cox proportional hazards models were used to analyze associations between the 3 exposure measures and T1DM incidence. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were calculated. Models were adjusted for sex, race and ethnicity, birth year, mother's age, birth weight, gestational age, number of well-child visits, and study site. RESULTS: In a cohort of 584 171 children, the mean ADU was 38 days, the mean cumulative antigen exposure was 263 antigens (SD = 54), and the mean cumulative aluminum exposure was 4.11 mg (SD = 0.73). There were 1132 incident cases of T1DM. ADU (aHR = 1.01; 95% CI, 0.99-1.02) and cumulative antigen exposure (aHR = 0.98; 95% CI, 0.97-1.00) were not associated with T1DM. Cumulative aluminum exposure >3.00 mg was inversely associated with T1DM (aHR = 0.77; 95% CI, 0.60-0.99). CONCLUSIONS: The recommended schedule is not positively associated with the incidence of T1DM in children. These results support the safety of the recommended childhood immunization schedule.

Catch-up immunization for adolescents and young adults during pre-travel consultation in Japan.

Rubella and measles outbreaks in adults occur because of unimmunized or partially immunized status. Travel clinics play an important role in catch-up measles, rubella, mumps, and varicella immunization for adults. We evaluated the need for catch-up measles, rubella, mumps, and varicella immunization by young adults at our travel clinic. This retrospective observational study was conducted at the National Center for Global Health and Medicine from June 1, 2017 to May 31, 2018. Adults aged 16-49 years who received pre-travel consultation and had childhood immunization records were included. Individuals who fully or partially received planned measles, rubella, mumps, and varicella catch-up immunization were classified as "immunized." We calculated the proportion of "immunized" individuals and analyzed the factors associated with catch-up measles, rubella, mumps, and varicella immunization at pre-travel consultation using logistic regression analysis. Overall, 3,456 individuals received pre-travel consultations during the study period; 827 (336 men, median age 22 years) had childhood immunization records. The most common trip purposes were study (33%) and tourism (24%). The most common destination was Asia (39%). Catch-up immunization of any measles, rubella, mumps, and varicella vaccine was needed by 755 individuals. After consultation, 20-46% of these participants who needed catchup immunization received at least one dose of immunization. Factors that are negatively associated with measles, rubella, mumps, and varicella catch-up immunization were tourism (odds ratio 0.37 to 0.58), yellow fever vaccination (0.45 to 0.50) (excluding varicella), and each disease history (0.13 to 0.40) (excluding rubella and varicella). Further studies are needed to identify barriers to catch-up immunization.

Sars-Cov-2 virus and vaccination; biological and statistical framework.

INTRODUCTION: The Development of the SARS-CoV-2 virus vaccine and its update on an ongoing pandemic is the first subject of the world health agenda. AREAS COVERED: First, we will scrutinize the biological features of the measles virus (MV), variola virus (smallpox virus), influenza virus, and their vaccines to compare them with the SARS-CoV-2 virus and vaccine. Next, we will discuss the statistical details of measuring the effectiveness of an improved vaccine. EXPERT OPINION: Amidst the pandemic, we ought to acknowledge our prior experiences with respiratory viruses and vaccines. In the planning stage of observational Phase-III vaccine effectiveness studies, the sample size, sampling method, statistical model, and selection of variables are crucial in obtaining high-quality and valid results.

Response to Vaccination against Mumps in Medical Students: Two Doses Are Needed.

Mumps is a vaccine-preventable infectious disease diffuse worldwide. The implementation of mumps vaccination reduced largely the spread of infection. On 11,327 Medical School students the prevalence of mumps positive antibodies was evaluated according to dose/doses of vaccine, year of birth and sex. Compliance to mumps vaccine was low in students born before 1990 but increased consistently after this year, above all compliance to two doses, due to the implementation of the vaccine offer. Positivity of mumps antibodies is significantly (p < 0.0001) lower in students vaccinated once (71.2%) compared to those vaccinated twice (85.4%). In addition, students born after 1995, largely vaccinated twice, showed a seropositivity near to 90%. Further, females had a significantly (p < 0.0001) higher proportion of positive antibodies after vaccination than males, both one (74.6% vs. 64.7%) and two doses (86.8% vs. 82.9%). Finally, seropositivity after two vaccine doses remains high (86.1%) even 15 years after the second dose. In conclusion, the research highlighted that vaccination against mumps reaches a good level of coverage only after two doses of vaccine persisting at high levels over 15 years and induces a more significant response in females.

Mumps outbreak among fully vaccinated school-age children and young adults, Portugal 2019/2020.

On 16-17 January 2020, four suspected mumps cases were reported to the local Public Health Authorities with an epidemiological link to a local school and football club. Of 18 suspected cases identified, 14 were included in this study. Laboratory results confirmed mumps virus as the cause and further sequencing identified genotype G. Our findings highlight that even with a high MMR vaccine coverage, mumps outbreaks in children and young adults can occur. Since most of the cases had documented immunity for mumps, we hypothesise that waning immunity or discordant mumps virus strains are likely explanations for this outbreak.

Repurposing of the childhood vaccines: could we train the immune system against the SARS-CoV-2.

INTRODUCTION: The COVID-19 pandemic is a globalized health concern caused by a beta-coronavirus named Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Since December 2019, when this outbreak flared in Wuhan, China, COVID-19 cases have been continuously rising all over the world. Due to the emergence of SARS-CoV-2 mutants, subsequent waves are flowing in a faster manner as compared to the primary wave, which is more contagious and causing higher mortality. Recently, India has emerged as the new epicenter of the second wave by mutants of SARS-CoV-2. After almost eighteen months of this outbreak, some COVID-19 dedicated therapeutics and vaccines are available, and a few are under trial, but the situation is still uncontrolled. AREA COVERED: This perspective article covers the repurposing of childhood vaccines like Bacille Calmette-Guerin (BCG), Measles, Mumps, Rubella (MMR), and Oral Polio Vaccine (OPV), which are live attenuated vaccines and have been shown the protective effect through 'trained immunity and 'crossreactivity.' EXPERT OPINION: This perspective article has suggested that combinatorial use of these childhood vaccines might exert a better protective effect along with the available COVID-19 therapeutic and vaccines which could be considered as a preventive option against SARS-CoV-2 infection as well as its subsequent waves.

Evaluation of the Safety and Immunogenicity of M-M-RII (Combination Measles-mumps-rubella Vaccine): Clinical Trials of Healthy Children and Adults Published Between 2010 and 2019.

BACKGROUND: The safety and immunogenicity of M-M-RII (measles, mumps and rubella virus vaccine live, Merck & Co., Inc., West Point, PA)-the only combined measles, mumps and rubella vaccine licensed for use in the United States-were previously reported in pre- and postlicensure clinical trials conducted from 1988 to 2009. M-M-RII continues to be evaluated as a comparator in clinical trials of other vaccines. Here, we review safety and efficacy data from more recent clinical trials of M-M-RII. METHODS: We performed a systematic literature review of trials using M-M-RII published from 2010 to 2019. RESULTS: In the 15 studies that met the inclusion criteria, a total of 12,032 subjects were vaccinated: 7667 persons received a first dose only, 2137 participated in 2-dose studies (128 received 1 dose and 2009 received both) and 2063 received a single dose of M-M-RII as their second dose. Dose number was not specified for 165 participants, ≥6 years old, in 2 studies in which a single dose of M-M-RII was administered. Similar to previous reports, M-M-RII was well tolerated and immunogenic when administered alone or concomitantly with other routinely recommended vaccinations. The most common adverse events included transient injection site pain and fever. Serious adverse events were extremely rare, with only 4 probable or potential vaccine-related events reported among the 12,032 participating subjects. CONCLUSIONS: In trials published from 2010 to 2019, M-M-RII continued to be safe and immunogenic in all age groups studied. These data, along with the results of earlier trials, indicate that the performance of the vaccine has been consistent across more than 30 years of postlicensure studies.

Vaccine completion and infectious diseases screening in a cohort of adult refugees following resettlement in the U.S.: 2013-2015.

BACKGROUND: Refugees are frequently not immune to vaccine-preventable infections. Adherence to consensus guidelines on vaccination and infectious diseases screening among refugees resettling in the U.S. is unknown. We sought to determine rates of vaccine completion and infectious diseases screening in refugees following resettlement. METHODS: We conducted a retrospective cohort study of refugees resettling in a region in the U.S. using medical data from June 2013-April 2015. We determined the proportion of vaccine-eligible refugees vaccinated with measles-mumps-rubella (MMR), hepatitis A/B, tetanus, diphtheria, and acellular pertussis (Tdap), and human papillomavirus (HPV) following resettlement. We also determined the proportion of refugees who completed HIV and hepatitis C (HCV) screening. RESULTS: One hundred and eleven subjects were included, primarily from Iraq (53%), Afghanistan (19%), and Eritrea (11%). Of the 84 subjects who were vaccine-eligible, 78 (93%) initiated and 42 (50%) completed vaccinations within one year of resettlement. Odds of completing vaccination were higher for men (OR: 2.38; 95%CI:1.02-5.71) and for subjects with English proficiency (OR: 3.70; 95%CI:1.04-17.49). Of the 78 subjects (70%) completing HIV screening, two (3%) were diagnosed with HIV. Nearly all subjects completed screening for HCV, and one had active infection. CONCLUSION: While most refugees initiate vaccinations, only 50% completed vaccinations and 70% completed HIV screening within 1 year of resettlement. There is a need to emphasize vaccine completion and HIV screening in refugee patients following resettlement.

Effectiveness of "Priorix" Against Measles and Mumps Diseases in Children Born After 2004 in the United Kingdom: A Retrospective Case-control Study Using the Clinical Practice Research Datalink GOLD Database.

BACKGROUND: Evidence on vaccine effectiveness (VE) may encourage vaccination and help fight the reemergence of measles and mumps in Europe. However, limited data exist on real-life effectiveness of individual measles, mumps and rubella (MMR) vaccines. This study evaluated VE of GSK's MMR vaccine ("Priorix") against measles and mumps. METHODS: This retrospective, case-control study used UK data from the Clinical Practice Research Datalink GOLD linked to the Hospital Episode Statistics database to identify children 1-13 years old diagnosed with measles or mumps from January 2006 to December 2018. Cases were matched to controls according to birth month/year and practice region. Cases were identified using clinical codes (without laboratory confirmation). "Priorix" exposure was identified using vaccine batch identifiers. Children exposed to other MMR vaccines were excluded. Adjusted VE was estimated for ≥1 vaccine dose in all children, and for 1 dose and ≥2 doses in children ≥4 years at diagnosis. RESULTS: Overall, 299 measles cases matched with 1196 controls (87.6% <4 years old), and 243 mumps cases matched with 970 controls (74.2% <4 years old) were considered. VE for ≥1 dose in all children was 78.0% (97.5% confidence interval: 67.2%-85.3%) for measles and 66.7% (48.1%-78.6%) for mumps. In children ≥4 years old, VE after 1 dose was 74.6% (-21.7% to 94.7%) for measles and 82.3% (32.7%-95.3%) for mumps, and VE after ≥2 doses was 94.4% (79.7%-98.5%) for measles and 86.5% (64.0%-94.9%) for mumps. CONCLUSIONS: "Priorix" is effective in preventing measles and mumps in real-life settings.