Immunity against measles, mumps, rubella, and varicella among homeless individuals in Germany - A nationwide multi-center cross-sectional study.

Introduction: Homeless individuals suffer a high burden of vaccine-preventable infectious diseases. Moreover, they are particularly susceptible to adverse infection outcomes with limited access to the health care system. Data on the seroprevalence of measles, mumps, rubella, and varicella within this cohort are missing. Methods: The seroprevalence of measles, mumps, rubella, and varicella was determined within the homeless population in Germany. Predictors of lacking immune protection were determined using multivariable logistic regression analysis. Results: Homeless individuals in Germany (n = 611) showed a seroprevalence of 88.5% (95% CI: 85.8-91.0) for measles, 83.8% (95% CI: 80.6-86.6) for mumps, 86.1% (95% CI: 83.1-88.7) for rubella, and 95.7% (95% CI 93.8-97.2) for varicella. Measles seroprevalences declined from individuals born in 1965 to individuals born in 1993, with seroprevalences not compatible with a 95% threshold in individuals born after 1980. For mumps, seroprevalences declined from individuals born in 1950 to individuals born in 1984. Here, seroprevalences were not compatible with a 92% threshold for individuals born after 1975. Seronegativity for measles, mumps and rubella was associated with age but not with gender or country of origin. Discussion: Herd immunity for measles and mumps is not achieved in this homeless cohort, while there was sufficient immune protection for rubella and varicella. Declining immune protection rates in younger individuals warrant immunization campaigns also targeting marginalized groups such as homeless individuals. Given that herd immunity thresholds are not reached for individuals born after 1980 for measles, and after 1975 for mumps, vaccination campaigns should prioritize individuals within these age groups.

Multiplex Bead Assay for the Serological Surveillance of Measles and Rubella.

There is increasing interest in evaluating antibody responses to multiple antigen targets in a single assay. Immunity to measles and rubella are often evaluated together because immunity is provided through combined vaccines and because routine immunization efforts and surveillance for measles and rubella pathogens are combined in many countries. The multiplex bead assay (MBA) also known as the multiplex immunoassay (MIA) described here combines the measurement of measles- and rubella-specific IgG antibodies in serum quantitatively according to international serum standards and has been successfully utilized in integrated serological surveillance.

A measles and rubella vaccine microneedle patch in The Gambia: a phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial.

BACKGROUND: Microneedle patches (MNPs) have been ranked as the highest global priority innovation for overcoming immunisation barriers in low-income and middle-income countries. This trial aimed to provide the first data on the tolerability, safety, and immunogenicity of a measles and rubella vaccine (MRV)-MNP in children. METHODS: This single-centre, phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial was conducted in The Gambia. To be eligible, all participants had to be healthy according to prespecified criteria, aged 18-40 years for the adult cohort, 15-18 months for toddlers, or 9-10 months for infants, and to be available for visits throughout the follow-up period. The three age cohorts were randomly assigned in a 2:1 ratio (adults) or 1:1 ratio (toddlers and infants) to receive either an MRV-MNP (Micron Biomedical, Atlanta, GA, USA) and a placebo (0·9% sodium chloride) subcutaneous injection, or a placebo-MNP and an MRV subcutaneous injection (MRV-SC; Serum Institute of India, Pune, India). Unmasked staff ransomly assigned the participants using an online application, and they prepared visually identical preparations of the MRV-MNP or placebo-MNP and MRV-SC or placebo-SC, but were not involved in collecting endpoint data. Staff administering the study interventions, participants, parents, and study staff assessing trial endpoints were masked to treatment allocation. The safety population consists of all vaccinated participants, and analysis was conducted according to route of MRV administration, irrespective of subsequent protocol deviations. The immunogenicity population consisted of all vaccinated participants who had a baseline and day 42 visit result available, and who had no protocol deviations considered to substantially affect the immunogenicity endpoints. Solicited local and systemic adverse events were collected for 14 days following vaccination. Unsolicited adverse events were collected to day 180. Age de-escalation between cohorts was based on the review of the safety data to day 14 by an independent data monitoring committee. Serum neutralising antibodies to measles and rubella were measured at baseline, day 42, and day 180. Analysis was descriptive and included safety events, seroprotection and seroconversion rates, and geometric mean antibody concentrations. The trial was registered with the Pan African Clinical Trials Registry PACTR202008836432905, and is complete. FINDINGS: Recruitment took place between May 18, 2021, and May 27, 2022. 45 adults, 120 toddlers, and 120 infants were randomly allocated and vaccinated. There were no safety concerns in the first 14 days following vaccination in either adults or toddlers, and age de-escalation proceeded accordingly. In infants, 93% (52/56; 95% CI 83·0-97·2) seroconverted to measles and 100% (58/58; 93·8-100) seroconverted to rubella following MRV-MNP administration, while 90% (52/58; 79·2-95·2) and 100% (59/59; 93·9-100) seroconverted to measles and rubella respectively, following MRV-SC. Induration at the MRV-MNP application site was the most frequent local reaction occurring in 46 (77%) of 60 toddlers and 39 (65%) of 60 infants. Related unsolicited adverse events, most commonly discolouration at the application site, were reported in 35 (58%) of 60 toddlers and 57 (95%) of 60 infants that had received the MRV-MNP. All local reactions were mild. There were no related severe or serious adverse events. INTERPRETATION: The safety and immunogenicity data support the accelerated development of the MRV-MNP. FUNDING: Bill & Melinda Gates Foundation.

Development of a real-time fluorescent reverse transcription loop-mediated isothermal amplification assay with quenching primers for rapid detection of rubella virus.

Rubella virus infection during early pregnancy sometimes causes severe birth defects termed congenital rubella syndrome. Although there are safe and effective live-attenuated vaccines, rubella has only been certified as eliminated in the Americas within the six World Health Organization regions. Rubella remains an endemic disease in many regions, and outbreaks occur wherever population immunity is insufficient. There are two main methods for diagnosis of rubella: detection of anti-rubella IgM antibodies by enzyme immunoassay and detection of the viral genome by real-time RT-PCR. Both of these methods require substantial time and effort. In the present study, a rapid rubella detection assay using real-time fluorescent reverse transcription loop-mediated isothermal amplification with quenching primers was developed. The time required for the new assay was one-half that required for a real-time RT-PCR assay. The assay had 93.6% positive percent agreement and 100% negative percent agreement for clinical specimens compared with the real-time RT-PCR assay. The new assay is considered useful for diagnosis of rubella in areas where rubella is endemic.

Rubella in Poland in 2021. / Rózyczka w Polsce w 2021 roku.

INTRODUCTION: Rubella is a viral infectious disease, and humans are the only reservoir of the virus. In 2020, all WHO member countries conducted epidemiological surveillance for rubella, and almost all (99%) had access to rubella testing at laboratories operating under the WHO Global Measles and Rubella Laboratory Network. OBJECTIVES: The aim of this study was to evaluate epidemiological indicators of rubella in Poland in 2021 compared to previous years, taking into account the impact of the COVID-19 pandemic. MATERIAL AND METHODS: The assessment of the epidemiological situation was based on a review of data from the bulletin , "Infectious Diseases and Poisons in Poland in 2021" (5), and the assessment of the immunization status of the population was based on data from the bulletin , "Immunization in Poland in 2021" (6). Classification of cases was made based on the definition used in the 2021 surveillance (7). Data from the epidemiological surveillance system "EpiBase" were also used. RESULTS: In 2021, 50 cases of rubella were registered, 48 fewer than in 2020 (98 cases). There was also a decrease in incidence to 0.13 per 100,000, compared to 0.26 per 100,000 in 2020. The highest incidence, regardless of gender and residential environment, was recorded in the 0-4 age group (1.23 per 100 thousand). No cases of congenital rubella syndrome were reported in 2021. CONCLUSIONS: In 2021, there was a decrease in the number of rubella cases in Poland, which could be a result of the COVID-19 pandemic and the introduced restrictions. In addition, rubella was registered 99% on the basis of clinical diagnoses, without the required laboratory confirmation, which means that other rash diseases could be registered as rubella.

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 case of congenital rubella syndrome and epidemiology of related cases in China, 2014-2023.

Rubella is a major cause of congenital defects, and the presence of rubella infection in a pregnant woman may lead to fetal death or congenital defects known as congenital rubella syndrome(CRS). Since China has not yet established a national CRS surveillance system, the true incidence cannot be determined. To understand the disease burden and epidemiological characteristics of CRS cases in China, the article reports the first case of CRS in Quzhou, China, and conducts a retrospective analysis of related cases that have been reported in China over the past decade. Because the availability of rubella-containing vaccines (RCV) was not widespread in China before 2008, women of childbearing age born before 2008 are generally unvaccinated against RCV. Due to the lack of routine CRS monitoring and screening, CRS is underreported in China. Vaccination of nonimmune women of childbearing age with RCV and establishing a sensitive and timely case-based CRS surveillance system can accelerate the elimination of rubella and CRS.

Case report: Rubella virus-associated cutaneous granuloma in an adult with TAP1 deficiency.

Rubella virus-associated granulomas commonly occur in immunocompromised individuals, exhibiting a diverse range of clinical presentations. These manifestations can vary from predominantly superficial cutaneous plaques or nonulcerative nodules to more severe deep ulcerative lesions, often accompanied by extensive necrosis and significant tissue destruction. TAP1 deficiency, an exceedingly rare primary immune-deficiency disorder, presents with severe chronic sino-pulmonary infection and cutaneous granulomas. This report highlights the occurrence of rubella virus-associated cutaneous granulomas in patients with TAP1 deficiency. Notably, the pathogenic mutation responsible for TAP1 deficiency stems from a novel genetic alteration that has not been previously reported. This novel observation holds potential significance for the field of diagnosis and investigative efforts in the context of immunodeficiency disorders.

Age-specific prevalence of IgG against measles/rubella and the impact of routine and supplementary immunization activities: A multistage random cluster sampling study with mathematical modelling.

BACKGROUND: Vietnam continues to have measles and rubella outbreaks following supplementary immunization activities (SIA) and routine immunization despite both having high reported coverage. To evaluate immunization activities, age-specific immunity against measles and rubella, and the number of averted Congenital Rubella Syndrome (CRS) cases, must be estimated. METHODS: Dried blood spots were collected from 2091 randomly selected individuals aged 1-39 years. Measles and rubella virus-specific immunoglobulin G (IgG) were measured by enzyme immunoassay. Results were considered positive at ≥120 mIU/mL for measles and ≥10 IU/mL for rubella. The number of CRS cases averted by immunization since 2014 were estimated using mathematical modelling. RESULTS: Overall IgG seroprevalence was 99.7% (95%CI: 99.2-99.9) for measles and 83.6% (95%CI: 79.3-87.1) for rubella. Rubella IgG seroprevalence was higher among age groups targeted in the SIA than in non-targeted young adults (95.4% [95%CI: 92.9-97.0] vs 72.4% [95%CI: 63.1-80.1]; P < 0.001). The estimated number of CRS cases averted in 2019 by immunization activities since 2014 ranged from 126 (95%CI: 0-460) to 883 (95%CI: 0-2271) depending on the assumed postvaccination reduction in the force of infection. CONCLUSIONS: The results suggest the SIA was effective, while young adults born before 1998 who remain unprotected for rubella require further vaccination.

Identifying the population susceptible to rubella in Japan, 2020: Fine-scale risk mapping.

BACKGROUND: Rubella remains a public health challenge in Japan, impeding the attainment of herd immunity. Despite vaccination efforts since 1976, persistent outbreaks reveal a susceptibility gap in male adults born before 1995. Seroepidemiological surveys are pivotal in evaluating population immunity and identifying at-risk groups. METHODS: This study aims to pinpoint high-risk areas for potential rubella outbreaks in Japan by merging seroepidemiological data from 2020 with population census information. Various data sources, including spatial demographic data, reported rubella and congenital rubella syndrome (CRS) cases, and traveler lodging statistics, were employed. Geospatial information for Japan's 230,300 small geographic areas was analyzed, and HI (hemagglutination inhibition) titers were examined by age and sex. Seroconversion was defined as an HI titer ≥ 1:32 or 1:16, indicating protective immunity. Geospatial maps illustrated the distribution of susceptible individuals per square kilometer, emphasizing high-risk urban areas like Tokyo and Osaka. Demographic shifts in the working-age population were assessed. RESULTS: Susceptible individuals cluster in densely populated urban centers, persisting despite demographic changes. The study highlights areas at risk of increased susceptibility, particularly with an HI titer cut-off of 1:16. Foreign travelers pose potential rubella importation risks as travel volume to Japan rises. To prevent epidemics and congenital rubella syndrome burden, achieving and sustaining herd immunity in high-risk areas is crucial. CONCLUSIONS: This study offers a comprehensive assessment of vulnerability in densely populated Japanese regions. Integrating population statistics with seroepidemiological data enhances our understanding of population immunity, guiding resource allocation for supplementary vaccination planning. To avert rubella epidemics, high-risk locations must bolster indirect protection through herd immunity, ultimately preventing congenital rubella syndrome.

Estimating the health effects of COVID-19-related immunisation disruptions in 112 countries during 2020-30: a modelling study.

BACKGROUND: There have been declines in global immunisation coverage due to the COVID-19 pandemic. Recovery has begun but is geographically variable. This disruption has led to under-immunised cohorts and interrupted progress in reducing vaccine-preventable disease burden. There have, so far, been few studies of the effects of coverage disruption on vaccine effects. We aimed to quantify the effects of vaccine-coverage disruption on routine and campaign immunisation services, identify cohorts and regions that could particularly benefit from catch-up activities, and establish if losses in effect could be recovered. METHODS: For this modelling study, we used modelling groups from the Vaccine Impact Modelling Consortium from 112 low-income and middle-income countries to estimate vaccine effect for 14 pathogens. One set of modelling estimates used vaccine-coverage data from 1937 to 2021 for a subset of vaccine-preventable, outbreak-prone or priority diseases (ie, measles, rubella, hepatitis B, human papillomavirus [HPV], meningitis A, and yellow fever) to examine mitigation measures, hereafter referred to as recovery runs. The second set of estimates were conducted with vaccine-coverage data from 1937 to 2020, used to calculate effect ratios (ie, the burden averted per dose) for all 14 included vaccines and diseases, hereafter referred to as full runs. Both runs were modelled from Jan 1, 2000, to Dec 31, 2100. Countries were included if they were in the Gavi, the Vaccine Alliance portfolio; had notable burden; or had notable strategic vaccination activities. These countries represented the majority of global vaccine-preventable disease burden. Vaccine coverage was informed by historical estimates from WHO-UNICEF Estimates of National Immunization Coverage and the immunisation repository of WHO for data up to and including 2021. From 2022 onwards, we estimated coverage on the basis of guidance about campaign frequency, non-linear assumptions about the recovery of routine immunisation to pre-disruption magnitude, and 2030 endpoints informed by the WHO Immunization Agenda 2030 aims and expert consultation. We examined three main scenarios: no disruption, baseline recovery, and baseline recovery and catch-up. FINDINGS: We estimated that disruption to measles, rubella, HPV, hepatitis B, meningitis A, and yellow fever vaccination could lead to 49 119 additional deaths (95% credible interval [CrI] 17 248-134 941) during calendar years 2020-30, largely due to measles. For years of vaccination 2020-30 for all 14 pathogens, disruption could lead to a 2·66% (95% CrI 2·52-2·81) reduction in long-term effect from 37 378 194 deaths averted (34 450 249-40 241 202) to 36 410 559 deaths averted (33 515 397-39 241 799). We estimated that catch-up activities could avert 78·9% (40·4-151·4) of excess deaths between calendar years 2023 and 2030 (ie, 18 900 [7037-60 223] of 25 356 [9859-75 073]). INTERPRETATION: Our results highlight the importance of the timing of catch-up activities, considering estimated burden to improve vaccine coverage in affected cohorts. We estimated that mitigation measures for measles and yellow fever were particularly effective at reducing excess burden in the short term. Additionally, the high long-term effect of HPV vaccine as an important cervical-cancer prevention tool warrants continued immunisation efforts after disruption. FUNDING: The Vaccine Impact Modelling Consortium, funded by Gavi, the Vaccine Alliance and the Bill & Melinda Gates Foundation. TRANSLATIONS: For the Arabic, Chinese, French, Portguese and Spanish translations of the abstract see Supplementary Materials section.

Post-campaign coverage evaluation of a measles and rubella supplementary immunization activity in five districts in India, 2019-2020.

BACKGROUND: In alignment with the Measles and Rubella (MR) Strategic Elimination plan, India conducted a mass measles and rubella vaccination campaign across the country between 2017 and 2020 to provide a dose of MR containing vaccine to all children aged 9 months to 15 years. We estimated campaign vaccination coverage in five districts in India and assessed campaign awareness and factors associated with vaccination during the campaign to better understand reasons for not receiving the dose. METHODS AND FINDINGS: Community-based cross-sectional serosurveys were conducted in five districts of India among children aged 9 months to 15 years after the vaccination campaign. Campaign coverage was estimated based on home-based immunization record or caregiver recall. Campaign coverage was stratified by child- and household-level risk factors and descriptive analyses were performed to assess reasons for not receiving the campaign dose. Three thousand three hundred and fifty-seven children aged 9 months to 15 years at the time of the campaign were enrolled. Campaign coverage among children aged 9 months to 5 years documented or by recall ranged from 74.2% in Kanpur Nagar District to 90.4% in Dibrugarh District, Assam. Similar coverage was observed for older children. Caregiver awareness of the campaign varied from 88.3% in Hoshiarpur District, Punjab to 97.6% in Dibrugarh District, Assam, although 8% of children whose caregivers were aware of the campaign were not vaccinated during the campaign. Failure to receive the campaign dose was associated with urban settings, low maternal education, and lack of school attendance although the associations varied by district. CONCLUSION: Awareness of the MR vaccination campaign was high; however, campaign coverage varied by district and did not reach the elimination target of 95% coverage in any of the districts studied. Areas with lower coverage among younger children must be prioritized by strengthening the routine immunization programme and implementing strategies to identify and reach under-vaccinated children.

Survey of the present health & nutritional status of Shompen tribe of Great Nicobar Island.

BACKGROUND OBJECTIVES: Shompens are one of the two mongoloid tribes of Nicobar district. There is little information about their recent health status since the last survey which was conducted in 1998. Hence, a comprehensive health and nutritional survey was conducted in March 2017 to assess the changes. The survey was carried out by a joint team of various organizations including the ICMR-Regional Medical Research Centre and Tribal Welfare and Health Department both located in Port Blair. METHODS: A detailed health and nutrition survey of the Shompen community was planned by deputing a field research team. The survey included demographic data, anthropometric data, clinical examination, screening for the markers of infectious diseases, respiratory pathogens, tuberculosis and haemoglobinopathies. RESULTS: About half of the Shompen adults (both males and females) had a body mass index (BMI) of ≥23. However, Shompen children had a good nutritional status with no child suffering from undernutrition. As per BMI for age, none of the children <5 yr were under-nourished, while in the 5-17 yr group, 12 per cent of children were undernourished. Anaemia prevalence was about 48.3 per cent, with 54 per cent prevalence in females and 43.8 per cent in males. Fungal infection of the skin, acute respiratory infection and abdominal pain were the common morbidities observed. None had active pulmonary tuberculosis. Of 38 Shompens screened for IgG (immunoglobulin G) antibodies, 42.1 and 18.4 per cent were positive for measles and rubella, respectively. Seroprevalence of Leptospira was 35.5 per cent. The prevalence of hypertension was 13.2 per cent, whereas another 28.9 per cent were pre-hypertensive. INTERPRETATION CONCLUSIONS: The population structure of the Shompen is not skewed and under nutrition was not widely prevalent among the children of <5 yr. The other positive observations were the absence of malaria, filariasis and dengue. However, there was natural infection of measles and rubella. Fungal skin infection and intestinal parasitic infestations were widely prevalent. Although cardiovascular risk profile was low, there were signs of emerging risk of over-weight, hypertension and dyslipidaemia. These together with the high prevalence of smokeless tobacco use may have a serious effect on the cardiovascular disease susceptibility of the Shompen population in the future.

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.

Thirty-Seventh Meeting of the Caribbean Immunization Managers: Final Report. 30-31 October 2023, Belize City

The Thirty-Seventh Managers’ Meeting of the Caribbean Expanded Program on Immunization was held on 30–31 October 2023 at the Best Western Belize Plus Biltmore Plaza in Belize City, Belize. Sixty-five participants convened from 22 countries and territories of the British West Indies and the Dutch Caribbean. Participants included representatives from the ministries of health, Caribbean Public Health Agency, Caribbean Community, and Pan American Health Organization/World Health Organization (PAHO/WHO). The overall objective of the meeting was to analyze and review the achievements and challenges of 2022, with a view to reversing the gains that were lost over the two years since. In addition, the event provided an occasion to share experiences relating to the immunization program and to plan 2024 activities.

A paired measles-rubella catch-up campaign in Sichuan China to stop an outbreak and strengthen local immunization programs.

BACKGROUND: China has been working towards measles elimination, but in 2017, measles outbreaks occurred in Ganzi and Aba prefectures of Sichuan province, representing 95% of all provincial cases and jeopardizing measles elimination. METHODS: During March and April 2017, high-performing prefectures were paired with outbreak and other interested counties to jointly conduct a measles-rubella (MR) catch-up campaign, build population immunity, and strengthen the counties' programs. RESULTS: House-to-house search identified 88,383 children in Ganzi that lacked MCV vaccination; 85,144 (96.34%) were vaccinated. Search identified 33,683 children in Aba who were not vaccinated against measles; 33,074 (98.19%) were vaccinated. The supporting prefectures helped install Immunization Information Systems and enroll unvaccinated children into the immunization program.The outbreak ended within a month and incidence has remained low for the subsequent six years. CONCLUSION: A paired catch-up campaign represents an effective model of using measles elimination strategies to strengthen local immunization programs for long-term program effectiveness.

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.