Measles Antibody Research Articles

Lower Rate of Seropositivity to Measles Among Young Healthcare Personnel in New York City.

We examined the prevalence of measles antibody among 12 349 newly hired HCP between 2009 and 2019. Younger HCP were significantly more likely to have no immunity. Compared with a 92.2% seropositive rate among 1057 persons hired at age >50 years, only 84.4% of approximately 10 000 HCP aged <40 years had protective antibody.

A Serosurvey Identifying Vulnerability to Measles in Health Care Workers. A Hospital-Based Prospective Seroprevalence Study.

The aim of this serological survey was to assess the persistence of measles antibodies among health care workers (HCWs) at risk of incidental measles. A prospective study of measles-specific antibodies in serum samples obtained from a total of 2782 participants aged 19–89 years was conducted between May 2018 and December 2019. The seropositivity rate of 93.7% (95% CI: 92.4–94.9%) in fully vaccinated participants aged 19–48 years was significantly lower than that of 98.0% (95% CI: 96.5–99.0%) in participants naturally immunised before 54 years. A cohort of those born in 1971–1975, vaccinated predominantly with one dose, showed lower seropositivity persistence (86.6%) than those fully vaccinated with two doses or naturally immunised. Otherwise, seropositivity was not markedly influenced by sex, age, smoking status, overweight, obesity or concomitant disease. The presence of sufficient antibody levels in a high proportion of HCWs irrespective of the way they acquired immunity is a favourable finding for managing incidental measles; hence, in the presence of a risk of a measles outbreak, it would be possible to perform targeted vaccination of only at-risk HCWs with a history of incomplete vaccination or missing information about the way in which immunity is acquired.

Nutritional Status and Measles Antibody Titer in Children Living in Urban Slums of Mumbai

Abstract Objectives To determine a) the prevalence of protective measles IgG titers in young children living in urban slums of Mumbai, and b) the association of nutritional status assessed through a combination of anthropometry and micronutrient biomarker concentrations with these titers at baseline and after 9 months of follow-up. Methods Anthropometry and serum concentrations of vitamins A, B12, D; ferritin, and zinc, and anti-measles immunoglobulin G (IgG) were measured among 12–24-month-old children in urban slums of Mumbai. Demographic data and health history were also collected. The association between baseline predictors and measles titers was assessed using linear regression for continuous measles titer and change in measles titer, and binomial regression for the dichotomous outcome of having a protective titer at baseline and at endpoint (&amp;gt;16.5 AU/mL). Results At baseline (n = 122, median age 14.5 months), 71% of children reported receiving dose 1 of the measles vaccine typically administered at 9 months of age, while 57% of children had protective measles IgG titers (&amp;gt;16.5 AU/mL). After 9 months of follow-up, 73% of children had protective titers. Multivariate models found measles IgG titer at baseline was inversely associated with vitamin D deficiency (&amp;lt;50 nmol/L) and vitamin B12 deficiency (&amp;lt; 148 pmol/L), and positively associated with child's age, maternal height, and birth weight. Iron deficiency (serum ferritin &amp;lt;15 ng/ml) at baseline was associated with lower measles IgG titers at endpoint (median age, 23.9 months). Conclusions The prevalence of protective antibody titer against measles virus in this pediatric urban slum population was less than anticipated, and age, maternal height, and birth weight were positively associated with increasing measles IgG titers. Deficiency in vitamins A, B12, and D, as well as iron, were associated with lower measles IgG titers, highlighting the potential role of micronutrient status in vaccine response. Funding Sources HarvestPlus.

Laboratory monitoring of postvaccination measles immunity

Measles vaccination In Russian Federation was introduced in 1967. It was assumed that the twodose vaccination regime would lead to a decrease in the incidence and elimination of measles. A number of studies have shown that up to 10% of individuals who received two doses of measles vaccine do not develop a specific humoral immunity, or do not maintain it at a protective level. This fact may contribute to gradual accumulation of persons susceptible for measles infection in the population, thus leading to emergence of new viral outbreaks in the future. The aim of this study was to perform dynamic monitoring of the post-vaccination measles immunity. The study involved 149 people. All the examined persons were divided into 2 groups. The group of comparison included persons, aged 19 to 51 years, in whom absence of measles immunity was serologically confirmed (n = 76). This group was twice vaccinated with live measles culture vaccine (NPO “Microgen”, Russia). Determination of IgG to measles virus was carried out 1 month after vaccination and revaccination. The control group consisted of persons with documented evidence of double immunization against measles virus, with laboratory-confirmed measles immunity (n = 73), aged 19 to 53 years. The comparative dynamics of development and contents of antibodies in the comparison-control groups were considered, with respect to the WHO age classification. Basic and postvaccinal dynamic determination of IgG to measles virus in serum was performed by ELISA using the “VectoKor-IgG” test system (Vector-Best, Novosibirsk). When analyzing the results of the study, it was noted that the level of measles immunity group in older persons from control group (over 45 years old) was initially higher, than in younger subjects. Among young people, the titers of specific measles antibodies reached the values of the control group of the corresponding age after the first vaccination, whereas the level of specific measles antibodies in older age group was significantly lower compared to the control group even after revaccination. A month after the first immunization, 4 people did not reach the protective level of anti-measles IgG. However, revaccination allowed them to form anti-measles immunity. In the course of our work, a case of non-response to vaccination was identified. Thus, our study showed a sufficient interindividual variability in humoral immune responses to measles vaccination.

Changes in Measles Seroprevalence in China After the Launch of Two Provincial Supplementary Immunization Activities During 2009 to 2013.

Supplementary immunization activities (SIAs) have been demonstrated being effective in reducing measles incidence within a short period of time in China, but the effects are short-lived if there is no follow-up SIA with high routine immunization coverage. To assess the change in measles seroprevalence from 2009 to 2013 after the launch of 2 large-scale SIAs within the period. Three population-based cross-sectional serologic surveys of measles antibodies were conducted in 2009, 2011 and 2013 in Zhejiang, a province in eastern China, with serologic samples collected from 1541, 896 and 1474 subjects, respectively. The serum levels of immunoglobulin G antibodies were measured by enzyme-linked immunosorbent assay. We found that the seropositivity rate among infants 0-7 months of age, a group having no vaccination benefit, was below 80% throughout the study period. In addition, the seropositivity rate among adults 30-49 years of age decreased significantly from 96.0% (95% confidence interval: 93.7%-98.3%) in 2011 to 88.5% (95% confidence interval: 84.3%-92.8%) in 2013. We showed that large-scale SIAs were effective, but their effects were not long lasting. Given the drop in seropositivity among adults, their susceptibility should be carefully monitored. While older individuals could benefit from the immunization activities, children who were too young to be vaccinated still have a weak seropositivity profile and the optimal age for the administration of the first dose of vaccine should be reconsidered.

A survey of examining herd measles immunity in adults over 35 years old

A high measles incidence rate has been registered in Russia in recent years, with adults being actively involved in the epidemic process (about 40% of patients), thereby underlying relevance of assessing herd immunity in different age groups to measure its risk. The data on examining serum antibodies to measles virus in 402 residents of Petrozavodsk are shown: 164 and 238 subjects were born in 1948–1968 (51–71 years) and 1970–1983 (36–50 years), respectively. It was found that the second group had significantly higher percentage not only of seropositive persons (94.1±1.5 vs. 77.4±3.3%, respectively), but also frequency of detected high IgG level (5 and more IU/l) reaching 39.7±3.5 vs. 15.4±5.8%, respectively. Analysis of vaccination history showed that of 351 people with protective antibody levels, 20.9% were vaccinated once or twice, 14 of them in childhood and 63 within the 15 years prior to the study. Of the 51 people with no measles antibodies or below protective level, 13.7% were vaccinated: five in childhood, and two within the last 15 years. Among those who was born in 1948–1968, 87.1±2.2% provided no information about previous vaccinations and probably were not vaccinated. In this group, percentage of those examined with a protective antibody level was significantly higher than in the 36–50 years group — 87.1±2.2 and 62.2±4.3%, respectively. In addition, 23 subjects confirmed that they recovered after measles in childhood. Of these, antibodies were detected in 21 subjects, including 9 having serum titer at level of 5 or more IU/ml. Until 1969, the Republic of Karelia registered a high level of measles morbidity (477–2176,0 per 100 thousand). The predominance in the group born before 1969, individuals seropositive to measles mainly at high titer, indicates that intense post-infectious immunity was preserved. The lack of protective level of antibodies to measles virus in 22.6% of persons aged 36–50 years (1969–1983 year of birth), due to the low level of post-infectious and insufficient durability of post-vaccination immunity allowing to definer them as a high risk group for measles infection.

Level of measles herd immunity assessed in hospital medical workers within a framework of the state measles elimination program

Within a framework of the state measles elimination program, in April, 2018 a level of measles herd immunity was assessed in 1899 Moscow hospital medical workers aged from 19 to 69 years and older. All subjects enrolled in the study were vaccinated against measles or recovered after measles infection. Serum samples were collected from subjects and examined by ELISA for measles IgG antibodies with the Vector-Best IgG-measle test system (Russia). It was found that 278 (14.6%) and 1621 (85.4%) subjects were seronegative ( 0.18 IU/mL) and seropositive ( 0.18 IU/ml), respectively. Age-related group distribution of 1855 serum samples revealed that percentage of seronegative subjects was in: aged 19—23 years was -38.5%; 24-28 and 29-33 years - 22.2%; 34-38 years - 27.5%; 39-43 years - 25.8%; 44-48 years - 16.8%; 49-53 and 54-58 years — 8.6% and 8.3%, respectively; 59-63 years old — 4.9%; 64-68 and over 69 years old — 0%. Moreover, mean level of measles IgG antibodies increased proportionally to age of medical workers from 0.58 IU/ml (19-23 years) to 2.94-2.72 IU/ml (64-68 and over 69 years). The data obtained indicate that a cohort of measles susceptible subjects (from 38.5% to 16.8%), respectively, is identified among young and middle age (from 19 to 48 years) individuals. It is assumed that two-dose measles vaccination in childhood does not contribute to the long-term preservation of protective levels of measles antibodies, thereby justifying a need to administer a three-dose measles vaccine.

Formation of humoral and cellular immunity to measles vaccine in adults

Despite adherence to the policy of mass measles vaccination in the majority of countries, this infection still remains far from being fully eradicated. Measles outbreaks are reported worldwide, when the vast majority of cases are recorded in subjects of 18—35 years of age. Studies on assessing measles IgG antibody level in different regions of Russia reveal increased percentage of measles seronegative subjects among young adults. Current study was aimed at investigating formation of humoral and cellular immunity after measles vaccination in seronegative adults aged 18 to 30 years old. There were enrolled 50 measles seronegative healthy volunteers aged 18 to 30 years old. Level of anti-measles IgM and IgG antibodies was measured by ELISA (Vector-Best, Russia). Subclasses of measles specific IgG antibodies were analyzed by ELISA, by replacing IgG conjugate for IgG1, IgG2, IgG3, IgG4 conjugates, whereas measles specific IgA antibodies were estimated by ELISA with IgA conjugate (Polygnost, Russia) at a concentration of 1 μg/ml. Antibody avidity was assessed by ELISA (Euroimmun, Germany). Cell-mediated measles immunity was estimated by CD107a surface expression on CD8hi T cell subset stimulated by measles virus-derived antigens. A specific cellular response to measles antigens before vaccination was detected in 50% of examined subjects, whereas 40% samples showed no signs of cellular immune response, with 10% of remaining cases described as equivocal. It was found that 6 weeks after vaccination all vaccinated subjects developed measles specific IgG antibodies at protective level reaching 1.33 (0.85—1.82) IU/ml [Me (LQ—UQ)]. Anti-measles IgA antibodies were of 0.655 (0.423—1.208) IU/ml [Me (LQ—UQ)]. However, no measles specific IgM antibodies were detected 6 weeks after vaccination. In addition, primary type of immune response (dominant low-avidity anti-measles antibodies IgG3 subclass) to measles vaccination was observed in 24 out of 50 subjects, whereas 26 subjects developed secondary type of immune response (high-avidity anti-measles antibodies dominated by IgG1 subclass). A measles specific cellular immune response was observed in 47 of the 50 examined subjects, and in 3 volunteers it was equivocal. Further analysis revealed a cohort of subjects who were not vaccinated against measles (18 subjects), although 60% of them provided medical record on previous dual measles vaccination occurred in childhood. Another cohort consisted of subjects who had medical record of measles vaccination in childhood (32 subjects), but lost protective measles antibodies produced by plasma cells (23 subjects), and memory T cells (3 subjects), or measles antibodies and memory B cells (6 subjects) over time. Such pattern evidences that measles-specific cellular and humoral arms immune responses were developed and maintained independently of each other.

Analysis of Measles Antibody Titers in the Staff of Gunma Chuo Hospital

Analysis of Measles Antibody Titers in the Staff of Gunma Chuo Hospital

Measles immunity in different population groups

Objective: to examine the state of the immunity to measles in different age groups.Materials and methods: In 2018, 4444 people were examined at the Diagnostic Center (virological). Among them, 3783 people were examined using the passive haemagglutination test for measles (manufactured by Pasteur Research Institute of Epidemiology and Microbiology, Russia). In the remaining 661 cases, the IgG to measles were detected using the enzyme-linked immunosorbent assay (ELISA) by VektoMeaseles IgG test (manufactured by Vector-Best, Russia). The correlation between the measles IgG level (ELISA) and the age was examined in 518 patients. Results: In this study, the immunity to measles was shown to be insufficient in all groups of observed people. Even among medical staff, nearly 10% had no protective level of measles antibodies. We have shown that the correlation between the measles IgG level and the age is statistically significant, so that the number of seronegative persons in different age groups differs significantly. Conclusion: The highest ratio of seronegative individuals was found in the age group between 18 and 25 years (52,33%), which can lead to serious measles outbreaks. Hence, this study confirms a strong need for additional immunization in all groups and especially in young population.

Prevalence of Measles Antibodies in S\xe3o Jos\xe9 do Rio Preto, S\xe3o Paulo, Brazil: A serological survey model

Measles is an acute and highly contagious but vaccine-preventable infectious disease. Despite years of being considered eliminated, decreased vaccination rates have produced virus reemergence in several countries, including Brazil. Measles can be controlled through immunization programs, through which aim to achieve 95% coverage with two doses of the vaccine. Measles can also be controlled if suspected cases can be properly identified in order to contain outbreaks. This cross-sectional study determined the prevalence of measles antibodies and their correlation with rubella antibodies (resulting from the combination vaccine used in Brazil’s public immunization program) in individuals aged higher 10 years old in São José do Rio Preto, São Paulo State, Brazil, participants of a prospective cohort of arbovirosis surveillance before virus reemergence in the country. Our findings presented that 32.9% of individuals aged 10–40 years old had not antibodies against measles; 39.3% of total individuals with documented evidence of measles vaccination did not have anti-measles IgG, though only 20.2% of individuals with documented evidence of rubella vaccination lacked anti-rubella IgG. Besides, the most of measles cases reported in the city, following the virus spreading in the country, occurred especially in groups defined by us as susceptible. Because the combination MMR vaccine is part of Brazil’s national vaccine schedule, the possible reasons for this relatively high rate of seronegativity need to be investigated further, once that it reflects outbreak risk.

Non-invasive detection of IgG antibodies from common pathogenic viruses using oral flocked swabs

Salivary antibodies are useful in surveillance and vaccination studies. However, low antibody levels and degradation by endonucleases are problematic. Oral flocked swabs are a potential non-invasive alternative for detecting viral antibodies. Seroprevalence for Cytomegalovirus (CMV), Varicella-Zoster virus (VZV), Epstein–Barr virus (EBV), Measles and Mumps IgG antibodies were determined from 50 matched serum, saliva and swabs samples from healthy volunteers using commercial ELISAs. CMV IgG, VZV IgG, and EBV EBNA-1 IgG, VCA IgG, and Measles IgG swab versus serum sensitivities were 95.8%, 96.0%, 92.1%, 95.5%, 84.5%, respectively, and swabs correlated well with saliva. Sensitivity of Mumps IgG in swabs and saliva was poor at 60.5%, and 68.2%, respectively. Specificities for IgG antibodies were 100% for CMV, EBV and Mumps, but could not be determined for VZV and Measles due to exclusively seropositive volunteers. Except for Mumps IgG, swabs correlate well with serum, are easy to self-collect and are stable at room temperature.

Measles immunity in a Czech tertiary care hospital

BackgroundGiven the increasing incidence of measles, the aim was to assess the seroprevalence of measles immunity among employees of a Czech tertiary care hospital and to assess their willingness to revaccination. Methods3027 hospital employees (2421 females, 606 males) underwent a serological analysis of their measles antibody levels with an option of revaccination in case of an insufficient level. ResultsThe median age of participants was 42 years. Seropositivity was noted in 54% of the participants, with the antibody values higher in the oldest study participants and with a decrease around the birth year 1968. Logistic regression analysis confirmed a significant relationship of seropositivity with age (odds ratio 0.97, p < 0.005). Out of the seronegative, 80.9% individuals got revaccinated. Conclusions46% of the participants did not reach a sufficient antibody level set by the assay's manufacturer. Although the routine vaccination system is well established it may be ineffective.

Measles Vaccination in Presence of Measles Antibody May Enhance Child Survival.

Background: In trials of early two-dose measles vaccination (MV), with the first dose being given before 9 months of age, vaccination in the presence of maternal antibody reduced mortality 2- to 3-fold compared with MV in the presence of no measles antibody. We tested this finding in two historical studies in which the children had received one dose of MV.Methods: We used data from a surveillance study of seroconversion after standard-titer MV (Schwarz strain) (Study 1) and a trial of early medium-titer MV (Edmonston-Zagreb strain) in which a pre-vaccination blood sample had been collected (Study 2). Both studies had control children, who were enrolled under similar conditions, but did not receive effective MV. Study 1 was a natural experiment where all children measles vaccinated during 1 month did not seroconvert and had therefore received an ineffective vaccine. In Study 2, the controls were randomized to an inactivated polio vaccine (IPV). We compared mortality for children with undetectable levels of measles antibody (<31.25 mIU) at baseline with children with detectable levels (≥31.25 mIU).Results: In both studies, children who were measles vaccinated in the presence of measles antibody had lower mortality compared with children who were measles vaccinated in presence of no measles antibody, the combined mortality rate ratio (MRR) being 0.51 (0.27–0.96). In the control groups, a detectable level of measles antibody vs. an undetectable level was not associated with lower mortality, the MRR being 1.40 (0.31–6.38).Conclusion: The results supported previous findings: measles vaccination in the presence of measles antibody had beneficial effects on child survival. Since maternal antibody levels are declining, it may be time to consider giving MV earlier and/or to provide MV to adolescent girls to boost antibody levels.

Seroprevalence to Measles Virus after Vaccination or Natural Infection in an Adult Population, in Italy

An increase in measles cases worldwide, with outbreaks, has been registered in the last few years, despite the availability of a safe and highly efficacious vaccine. In addition to an inadequate vaccination coverage, even in high-income European countries studies proved that some vaccinated people were also found seronegative years after vaccination, thus increasing the number of people susceptible to measles infection. In this study, we evaluated the immunization status and the seroprevalence of measles antibodies among 1092 healthy adults, either vaccinated or naturally infected, in order to investigate the persistence of anti-measles IgG. Among subjects who received two doses of measles vaccine, the neutralizing antibody titer tended to decline over time. In addition, data collected from a neutralization assay performed on 110 healthy vaccinated subjects suggested an inverse correlation between neutralizing antibody titers and the time elapsed between the two vaccinations, with a significant decline in the neutralizing titer when the interval between the two doses was ≥11 years. On the basis of these results, monitoring the serological status of the population 10–12 years after vaccination could be important both to limit the number of people who are potentially susceptible to measles, despite the high efficacy of MMR vaccine, and to recommend a booster vaccine for the seronegatives.

Effect of the Method for Immobilizing Receptor Layer on the Analytical Characteristics of a Label-Free Electrochemical Immunosensor for the Determination of Measles Antibodies

The effect of the method of immobilization of receptor layer on the analytical characteristics of label-free electrochemical immunosensors for determining antibodies to the measles virus is estimated. The receptor layer bearing the measles antigen was immobilized by dropping a model suspension on the surface of a glassy-carbon electrode, followed by drying in air and covalent crosslinking by electrografting of p-nitrophenyldiazonium chloride using glutaraldehyde as a crosslinking agent. The dependences of the peak current of the mediator system on the concentration of measles antibodies in model suspensions are linear and described by the equations I = –(28 ± 1)cat – (30 ± 4) and I = –(19 ± 2)cat – (15 ± 5) for the covalent immobilization and drop deposition of the receptor layer, respectively. Immobilization of the bioreceptor by covalent crosslinking does not lead to a significant improvement in the sensitivity of the determination; however, it expands the linear concentration range tenfold and decreases the total duration of the immunoassay procedure to 20 min with respect to the immunosensor with a drop-immobilized antigen.

Susceptibility to measles among health workers in a university hospital in southern Italy.

Measles still has a high impact on the health of the population in Italy and therefore requires a strong commitment to prevention at national level. In addition to Italy, measles outbreaks have also been reported in other EU countries, with a high number of cases and a rapid spread of the disease even in the nosocomial context between patients and health personnel. The aim of this study is to evaluate the prevalence of measles in a group of health workers working at a university hospital in southern Italy. A seroepidemiological study was conducted on 458 health workers. Measles antibody IgG and IgM levels were evaluated by immunoenzymatic testing. The highest percentage of susceptible subjects was ≤30 years old, with a statistically significant difference compared to the age group ≥51 years. With regard to gender, susceptibility to measles in males was significantly higher than in females (p<0.05). Additional statistically significant differences were found in the different age groups in both genders. Although the results show that most health workers are immune to measles, a 20% susceptibility certainly represents a risk for the spread of the disease among operators and patients. Vaccination and control of suspected cases, especially in community settings such as the hospital environment, are the main measures to prevent the transmission and spread of the disease.

Measles antibody levels among vaccinated and unvaccinated children 6–59 months of age in the Democratic Republic of the Congo, 2013–2014

BackgroundMeasles is endemic in the Democratic Republic of the Congo (DRC), and 89–94% herd immunity is required to halt its transmission. Much of the World Health Organization African Region, including the DRC, has vaccination coverage below the 95% level required to eliminate measles, heightening concern of inadequate measles immunity. MethodsWe assessed 6706 children aged 6–59 months whose mothers were selected for interview in the 2013–2014 DRC Demographic and Health Survey. History of measles was obtained by maternal report, and classification of children who had measles was completed using maternal recall and measles immunoglobulin G serostatus obtained from a multiplex chemiluminescent automated immunoassay dried blood spot analysis. A logistic regression model was used to identify associations of covariates with measles and seroprotection, and vaccine effectiveness (VE) was calculated. ResultsOut of our sample, 64% of children were seroprotected. Measles vaccination was associated with protection against measles (OR: 0.15, 95% CI: 0.03, 0.81) when administered to children 12 months of age or older. Vaccination was predictive of seroprotection at all ages. VE was highest (88%) among children 12–24 months of age. ConclusionOur results demonstrated lower than expected seroprotection against measles among vaccinated children. Understanding the factors that affect host immunity to measles will aid in developing more efficient and effective immunization programs in DRC.

Role of Pediatric Departments in Community Hospitals in Countermeasures against Measles Epidemics at Olympic Games Sites.

In preparation for the 2021 Tokyo Olympic/Paralympic Games, the Japanese government assessed the risks of infectious disease outbreaks and identified necessary preparations. This present study reviewed efforts made during a previous measles epidemic and describes the roles of hospitals. This descriptive study investigated the records of 198 children with measles. All children were treated at a general hospital during the period from January 1997 through February 1998. We also examined the actions of pediatricians during and after a measles outbreak in the community. Of the 198 children, 145 (73%) were hospitalized. The measles vaccination rate in the previous year was approximately 75%. Of the patients examined, 53% were younger than 2 years of age; mean age was 2.75 years. Pneumonia and gastroenteritis accounted for 46% and 30% of the complications, respectively. Issues requiring attention included the number of hospital beds located in a negative pressure room or private room with a window, the need for gamma globulin preparations with high measles antibody titers, the necessity of increasing vaccination opportunities, and extension of physician working hours. Visitors from other countries could cause measles outbreaks in Japan. Measures that might mitigate an outbreak were maintenance of high vaccination rates, ready availability of information on the location of negative pressure hospital rooms, knowledge of the status of the measle outbreak, and flexible medical staffing. There is a risk of measles outbreaks among infants and among those who do not have a measles antibody titer.

Comparison of the Seroprevalence of Measles Antibodies among Healthcare Workers in Two Korean Hospitals in 2019.

We performed a point seroprevalence survey of measles among healthcare workers (HCWs) at two Korean teaching hospitals in 2019. A total of 2,830 HCWs underwent an antibody test. The overall seropositivity of measles was 93.1%. The seroprevalence of measles was lowest in HCWs aged 20 - 24 years (81.2%), followed by those aged 25 - 29 years (90.1%). The rates of anti-measles IgG positivity were significantly different between the two hospitals (97.0% vs. 89.4%, P <0.001). These results suggest that the seropositivity of measles in HCWs may differ depending on the hospital's vaccination policy.