Measles Antibody Levels Research Articles

Waning of Humoral Immunity to Vaccine-Preventable Diseases in Children Treated for Acute Lymphoblastic Leukemia: A Single-Center Retrospective Cross-Sectional Analysis

The survival rates of children with acute lymphoblastic leukemia (ALL) have improved over the years, but infections remain a significant cause of morbidity and mortality. Chemotherapy has a range of harmful side effects including the loss of protective antibodies against vaccine-preventable diseases. The objective of this study was to evaluate the serological status of pediatric ALL cases before and after intensive chemotherapy. Children treated and followed for ALL at Dokuz Eylül University were included in this retrospective cross-sectional study. Antibody levels against hepatitis A, hepatitis B, and rubella were routinely assessed at both the time of diagnosis and 6 months after completion of chemotherapy. Measles, mumps, and varicella antibody levels were evaluated at only 6 months after treatment. Seventy-eight children who completed chemotherapy for ALL were enrolled in the study. All participants had non-protective antibody levels for at least one of the diseases. The highest seropositivity rate was found for hepatitis A (55.1%) and the lowest for measles (17.9%) after chemotherapy. Overall, 50.7%, 30.6%, and 45.7% of the patients significantly lost their humoral immunity against hepatitis B, hepatitis A, and rubella, respectively. Patients in the higher-risk group for ALL had lower seropositivity rates than patients of the other risk groups. There were statistically significant relationships between the protective antibody rates for hepatitis A and varicella and the ages of the patients. Except for hepatitis A vaccination, pre-chemotherapy vaccination did not affect post-chemotherapy serology. On the other hand, all children with a history of varicella before diagnosis showed immunity after chemotherapy. Patients with ALL, including those previously fully vaccinated, are at great risk of infection due to the decrease in protective antibody levels after chemotherapy. There is a need for routine post-chemotherapy serological testing and re-vaccination based on the results obtained.

A real-world study on the changing characteristics of measles antibodies in premature infants in China

ABSTRACT The waning of maternal antibodies may cause infants to lose protection against measles before receiving measles-containing vaccine (MCV). The aim of this study is to investigate the changing characteristics and influencing factors of measles antibodies in preterm infants (PT), and to provide scientific basis for optimizing MCV vaccination strategy of the target population. Blood samples were collected from PT and full-term infants (FT) at the chronological age (CA) of 3, 6, and 12 months. Measles antibodies were quantitatively detected by enzyme-linked immunosorbent assay. Demographic and vaccination information were both collected. Kruskal–Wallis rank sum test was used to compare the measles antibodies among different gestation age (GA) groups, and multiple linear regression was performed to identify the correlative factors for the antibodies. Measles antibodies of PT decreased significantly with age increasing before MCV vaccination. The positive rates of antibodies of PT were 10.80% and 3.30% at the age of 3 and 6 months, respectively (p < .001). At 12 months, the measles antibodies and seropositive rate in the infants who received MCV vaccination increased sharply (p < .001). Regression analyzes showed that the younger the GA or the older the age, the lower the antibodies at 3 months(p < .001，p = .018); while the lower measles antibody levels at 3 months and older age predicted the lower antibodies at 6 months(p < .001, p = .029). PT were susceptible to measles due to the low level of maternally derived antibodies before MCV vaccination. More efforts should be considered to protect the vulnerable population during their early postnatal life.

Long-term Neutralizing Antibody Levels Against Measles and Rubella Viruses Among Adults With 3 Doses of Measles-Mumps-Rubella Vaccine.

A third dose of measles-mumps-rubella vaccine (MMR) may be administered for various reasons, but data on long-term immunity are limited. We assessed neutralizing antibody levels against measles and rubella among adults up to 11 years after receipt of a third MMR dose. In this longitudinal study, healthy adults who received a third MMR dose as young adults (ages 18-28 years) were recalled around 5 years and 9-11 years after the third dose. Measles and rubella antibody levels were assessed by plaque-reduction and immunocolorimetric neutralization assays, respectively. Antibody concentrations <120 mIU/mL and <10 U/mL were considered potentially susceptible to measles and rubella, respectively. Geometric mean concentrations (GMCs) and 95% confidence intervals (CIs) over time were estimated from generalized estimating equation models. Approximately 5 and 9-11 years after receipt of the third dose, 405 and 304 adults were assessed, respectively. Measles GMC was 428 mIU/mL (95% CI, 392-468 mIU/mL) 5 years postvaccination, declining to 381 mIU/mL (95% CI, 339-428 mIU/mL) 11 years postvaccination. At the last follow-up visit (9-11 years postvaccination), 10% of participants were potentially susceptible to measles infection. Rubella GMCs were stable throughout the follow-up period (63 U/mL to 65 U/mL); none of the participants was susceptible to rubella at the last follow-up visit. Eleven years after receiving a third MMR dose, measles and rubella neutralizing antibody levels remained high in adults. However, on the basis of waning antibody levels, some adults may become susceptible to measles infection over time despite receipt of 3 vaccine doses.

1148. Long-term Persistence of Measles and Rubella Virus Neutralizing Antibody Levels among Adults with Three Doses of Measles-Mumps-Rubella Vaccine

Abstract Background A third dose of measles-mumps-rubella vaccine (MMR) may be administered for various reasons, but there are limited data on long-term immunogenicity. We assessed persistence of measles and rubella neutralizing antibodies among adults after receipt of three MMR doses. Methods Adults who received two MMR doses in childhood and a third dose as young adults (aged 18-28 years) in 2009-2010 were recalled at around 5 (2014-2016) and 9-11 (2019-2021) years after receipt of the third MMR dose. Measles and rubella antibody levels were assessed by plaque-reduction and soluble immunocolorimetric neutralization assays, respectively. Participants with measles antibody concentrations &amp;lt; 120 mIU/ml or rubella antibody concentrations &amp;lt; 10 U/mL were considered potentially susceptible to infection. Generalized estimating equations models were used to estimate geometric mean concentrations (GMC) and 95% confidence intervals (CI) of antibody levels over time. Results Approximately 5 and 9-11 years after receipt of the third MMR dose, 408 (aged 22-33 years) and 304 (aged 26-37 years) adults were reassessed, respectively. For measles, GMC was 428 mIU/mL (95% CI, 392 – 468 mIU/mL) at 5 years after the third MMR dose, declining to 381 mIU/mL (95% CI, 339 – 428 mIU/mL) at 11 years after the third MMR dose (Fig 1). Measles antibody concentrations during both long-term follow-up periods declined to levels lower than before receipt of the third dose (Fig 2). At the last follow-up visit (2019-2021), 10% of participants were potentially susceptible to measles infection compared to 3% before receipt of the third MMR dose up to 11 years earlier. For rubella, GMCs were stable throughout the long-term follow-up period (63 U/mL to 65 U/mL) (Fig 3). Rubella antibody concentrations during the long-term follow-up periods remained higher than levels before receipt of the third MMR dose and were similar to levels at 1 year after receipt of the third MMR dose (Fig 2). None of the participants were susceptible to rubella at the last follow-up visit. The solid black line shows the trend in population GMC estimates from before vaccination (0 year) through 12 years after receipt of the third MMR dose. The gray lines show the measles virus antibody concentrations over time for each individual. The dotted horizontal line shows concentration &amp;lt;120 mIU/mL used as the cutoff for susceptibility. The vertical dotted lines represent the cutoff for susceptibility. The geometric mean concentrations (GMCs) were estimated using generalized estimating equations model. The solid black line shows the trend in population GMC estimates from before vaccination (0 year) through 12 years after receipt of the third MMR dose. The gray lines show the rubella virus antibody concentrations over time for each individual. The dotted horizontal line shows concentration &amp;lt;10 U/mL used as the cutoff for susceptibility. Conclusion Neutralizing antibody levels to measles and rubella remained high and persisted through 11 years after vaccination among adults who received three MMR doses. However, some adults may become susceptible to measles infection over time despite receipt of three MMR doses. Disclosures Stephen N. Crooke, PhD, Bionano Genomics: Stocks/Bonds|Caribou Biosciences: Stocks/Bonds|Pfizer: Stocks/Bonds|Vistagen Therapeutics: Stocks/Bonds Huong McLean, PhD, MPH, Seqirus: Grant/Research Support

Association of arsenic exposure with measles antibody titers in US children: Influence of sex and serum folate levels

Exposure to arsenic during childhood is associated with various adverse health conditions. However, little is known about the effect of arsenic exposure on vaccine-related humoral immunity in children. We analyzed data from the National Health and Nutrition Examination Survey (2003–2004 and 2009–2010) to study the relationship between urinary arsenic and measles antibody levels in 476 US children aged 6–11. Multivariable linear regression was used to evaluate the association, adjusting for cycle, age, race, body mass index (BMI), serum cotinine, poverty index ratio, and vitamin B12 and selenium intakes. Stratified analyses were conducted by sex and serum folate levels using the median as cutoff (18.7 ng/mL). The measles antibody concentrations in the 3rd and 4th quartiles were found to have significantly decreased by 28.5 % (95 % Confidence Interval (CI) −47.6, −2.28) and 36.8 % (95 % CI −50.2, −19.5), compared to the lowest quartile among boys with serum folate levels lower than 18.7 ng/ml. The serum measles antibody titers significantly decreased by 16.7 % (95 %CI −25.0, −7.61) for each doubling of creatinine-corrected urinary total inorganic arsenic concentrations in the same group. No associations were found in boys with high serum folate levels or in girls. Further prospective studies are needed to validate these findings and develop interventions to protect children from infectious diseases.

Long-term immunoprotection after live attenuated measles-mumps-rubella booster vaccination in children with juvenile idiopathic arthritis

IntroductionVaccines, especially live attenuated vaccines, in children with JIA pose a great challenge due to both potential lower immunogenicity and safety as a result of immunosuppressive treatment. For many years, in the Netherlands, JIA patients receive a measles-mumps-rubella (MMR) booster vaccine at the age of nine years as part of the national immunization program. ObjectivesTo study long-term humoral immunoprotection in a large cohort of JIA patients who received the MMR booster vaccine while being treated with immunomodulatory therapies at the Wilhelmina Children’s Hospital in Utrecht, the Netherlands. MethodsMMR-specific IgG antibody concentrations in stored serum samples of vaccinated JIA patients were determined with chemiluminescent microparticle immunoassays (CMIA). Samples were analyzed five years after MMR booster vaccination and at last available follow-up visit using both crude and adjusted analyses. Additional clinical data were collected from electronic medical records. ResultsIn total, 236 samples from 182 patients were analyzed, including 67 samples that were available five years post-vaccination, and an additional 169 samples available from last visits with a median duration after vaccination of 6.9 years (IQR: 2.8–8.8). Twenty-eight patients were using biologic disease-modifying antirheumatic drugs (bDMARDS) of whom 96% anti-TNF agents and 4% tocilizumab. Percentages of protective antibody levels against measles after five years were significantly lower for patients who used bDMARD therapy at vaccination compared to patients who did not: 60% versus 86% (P = 0.03). For mumps (80% versus 94%) and rubella (60% versus 83%) this difference did not reach statistical significance (P = 0.11 and P = 0.07, respectively). Antibody levels post-vaccination decreased over time, albeit not significantly different between bDMARD users and non-bDMARD users. ConclusionThe MMR booster vaccine demonstrated long-term immunogenicity in the majority of children with JIA from a large cohort, although lower percentages of protective measles antibody levels were observed in bDMARD users. Hence, it might be indicated to measure antibody levels at least five years after MMR booster vaccination in the latter group and advice an extra booster accordingly.

Red Blood Cell Folate Modifies the Association between Serum Per- and Polyfluoroalkyl Substances and Antibody Concentrations in U.S. Adolescents.

Per- and polyfluoroalkyl substances (PFAS) exposure has been associated with reduced antibody levels. Higher red blood cell (RBC) folate was previously associated with lower serum PFAS concentrations in adolescents. This study included 819 adolescents aged 12-19 years who had detectable rubella and measles antibody levels in serum from the U.S. National Health and Nutrition Examination Survey 2003-2004 and 2009-2010 cycles. We found inverse associations between serum PFOS and PFHxS and rubella antibodies, between PFOA and mumps antibodies, and between PFAS mixtures and rubella and mumps antibodies, only among adolescents with RBC folate concentrations <66th percentile (lower folate group) while not among adolescents with higher RBC folate levels (upper folate group). Specifically, per quartile increase in serum concentrations of the total PFAS mixture was associated with a 9.84% (95% CI: -15.57%, -3.74%) decrease in rubella antibody and an 8.79% (95% CI: -14.39%, -2.82%) decrease in the mumps antibody concentrations only in the lower folate group, while null associations were found for the upper folate group. If confirmed in mechanistic studies or prospective epidemiologic studies, these findings may have important implications for using folate as a mitigation measure against immune-related PFAS effects.

Waning of maternal antibody against measles virus in Shufu, China

ABSTRACT Background: As measles vaccination coverage has increased, measles infection has shifted to the population of infants. We conducted a follow-up seroepidemiological study among mothers and their infants to evaluate measles seroprevalence and the persistence of maternal measles antibody in Shufu, Kashgar from 2018 to 2020. Methods: Maternal venous blood and cord blood was obtained among mothers and their infants at 0, 3, 5, 8, 9, and 12 months of age. An enzyme-linked immunosorbent assay was used for quantitative measurement of measles antibodies. We analyzed the correlation between maternal and neonatal measles antibodies, and antibodies persistence after infants were born. Results: The overall neonatal maternal ratio was 2.38 (95%CI: 2.05–2.71). The measles antibodies for mothers and newborns were 438.93 IU/mL (95%CI: 409.47–470.51 IU/mL) and 440.10 IU/mL (95%CI: 410.82–471.48 IU/mL), respectively. Neonatal measles antibodies were dropping after birth and then beginning to increase starting at 8 months of age. Conclusions: Infant measles antibody levels progressively declined after birth regardless of maternal measles antibody levels. Efforts should be carried out to eliminate measles.

Increasing seroprevalence but waning herd immunity against measles after elimination: Longitudinal seroepidemiology of measles in Osaka Prefecture, Japan, 2003–2020

Japan is one of the countries conducting longitudinal serosurveillance of vaccine-preventable diseases. We conducted surveillance of the local measles-specific antibody titer, calculated the effective reproduction number (Re), and compared data of four terms: term 1, 2003–2006 (before the introduction of the second shot of measles-containing vaccine); term 2, 2007–2010 (early term toward measles elimination); term 3, 2011–2014 (later term toward measles elimination); and term 4, 2015–2020 (after elimination of measles in Japan). Approximately 250 sera from volunteers aged 0 to ≥ 40 years were collected and examined for measles-specific IgG using the gelatin particle agglutination (PA) method annually from 2003 to 2020. Seroprevalence and the geometric mean of the PA antibody titer were examined by term. Re was calculated using the age-dependent proportion immune and contact matrix for each term. Of the 4,716 sera, 886 in term 1, 1,217 in term 2, 1,069 in term 3, and 1,544 in term 4 were collected. The seroprevalence gradually increased from term 1 (88.3% CI 86.0–90.3) to term 4 (95.7% CI 94.6–96.7), and the seroprevalence of term 1 was significantly lower than those of other terms (Fisher’s exact test, p < 0.001), with PA titer ≥ 16 as positive. By contrast, PA antibody titers significantly decreased from term 1 (median 1,024) to term 4 (median 256) (Mann–Whitney U test, p < 0.001). With the protection level (PA titer ≥ 128 and ≥ 256) as positive, Re gradually increased from term 1 (1.8 and 2.3) to term 4 (2.5 and 4.8, respectively). Waning levels of measles antibodies potentially increase the measles susceptibility in Osaka, Japan. This trend might imply a limitation of vaccine-induced immunity in the absence of a natural booster for wild strains after measles elimination. This study provides a cue for maintaining continuous measles elimination status in the future.

Measles Neutralization Antibodies and Some Related Factors in Women of Reproductive-age in Hanoi, Vietnam

Aims: Our study aimed to determine neutralization antibodies against measles virus and some related factors in women of childbearing-age from 18 to 30 years old, in Hanoi, Vietnam.&#x0D; Methodology: In 2018, a cross-sectional study was conducted on 1,235 childbearing-age women from 18-30 years old in Bavi district, Hanoi, Vietnam. The study participants were interviewed by using a structured questionnaire which included demographic information, and history of measles. The measles neutralization antibodies (MNA) of these participants were quantified by a plaque reduction neutralization test (PRNT). The data were analyzed using the Epidata 3.1 and Stata 14.2 software.&#x0D; Results: The results showed that only 58.5% had MNA at sufficient protective levels (≥120mIU/ml), up to 12.5% were negative for MNA, and 358 women (29%) had MNA at insufficient protective levels. In addition, we found that the participants’ working as public employees, having two children, and being ≥ 25 years of age were all positively associated with the sufficient protective antibody levels (P&lt;0.05). A weak positive correlation between age and MNA titers was determined (r= 0.26).&#x0D; Conclusion: Approximately half (41.5%) of the women of childbearing age in this study did not have sufficient protective antibodies against measles virus. The study results suggest that it is necessary to boost measles vaccine to prevent the sporadic measles infection in women of childbearing age in Hanoi and to quantify the dynamics of maternal measles antibody levels in infants born from these women, so as to provide evidences to control measles incidence in children up to 9 months of age in the future.

Subacute sclerosing panencephalitis (SSPE) without electroencephalographic evidence throughout the illness: An unusual finding, challenging the diagnosis

SSPE is a chronic progressive encephalitis due to persistent measles viral infection. Clinical features, neuroimaging, EEG, CSF and serum measles antibody levels assist in the diagnosis. We report a case of SSPE confirmed by CSF measles antibodies and MRI abnormalities but without myoclonus or characteristic EEG changes.

Low Seroprevalence of Measles-Specific IgG in Children of Three Ethnic Groups from Mexico: Influence of Age, Sex, Malnutrition and Family Size.

Background: The reemergence of measles represents a public health problem. The aim of the study was to determine the seroprevalence of IgG antibodies against measles in children of three ethnic groups in southern Mexico and the nutritional status and demographic risk factors associated. Methods: A cross-sectional study in 416 school-age children, 207 belonging to the Tlapaneco ethnic group, 101 to the Mixteco group and 108 were considered Mestizo. Sociodemographic data were collected, an anthropometric evaluation of the children was performed and a fasting blood sample was obtained from each child for the measurement of measles IgG antibodies by Enzyme-Linked Immunosorbent Assay (ELISA). Results: From the total sample, 59% of the children were seropositive for IgG antibodies against measles; in contrast, 41% lacked IgG antibodies. Measles antibody seropositivity was higher in girls (64%). 90.5% of 6-year-old children had higher antibodies seroprevalence, compared to the children between 10 and 13 years old (45.5%). In the three ethnic groups, age was negatively correlated with the index standard ratio (ISR) of measles antibody levels and the families with ≥8 members showed less seropositivity. According to the antibodies levels, most of the positive cases remained around 1 Standard Deviation (SD) of the ISR values and no underweight children had antibody levels above 2 SD. Conclusions: The Anti-Measles serological coverage is low in children of three ethnic groups from Southern Mexico and the age, sex, malnutrition and family size are associated factors. Therefore, it is important to strengthen immunization campaigns, principally in vulnerable groups.

In utero arsenic exposure modulates children's immune function

Title: In utero arsenic exposure modulates children’s immune functionBackground. Arsenic exposure occurs globally, and it is immunotoxic.Objective. We examined the association between drinking water arsenic exposure and immunological outcomes in a prospective cohort recruited in Bangladesh (2008-2018).Methods. Linear and Poisson regression models were used to evaluate the association between arsenic exposure and serum antibody (N=502) and infectious diseases (N=989) in children aged 5.Results. Median water arsenic (W-As) was 4.6μg/L in pregnancy. Comparing highest to lowest tertile of W-As, children aged 5 had a greater odds of clinically insufficient concentrations of diphtheria antibody (OR:1.91, 95%CI): 1.03, 3.56) after adjusting for income, maternal education, breastfeeding, birth, gender, age, and BMI. No association was observed with diphtheria or measles antibody levels. The incident rate ratios for each doubling of W-As were 1.10 (95% confidence interval [CI] = 1.00, 1.22) and 0.93 (95% CI = 0.82, 1.05) for respiratory and febrile illness, respectively, after adjusting for covariates.Conclusion. This study provides epidemiological evidence that chronic low level arsenic exposure from drinking water during pregnancy modulates children’s immunological functioning and increases their susceptibility to infectious respiratory diseases.

Arsenic exposure and Measles Antibody Titers in the US Children: NHANES 2003-2004 and 2009-2010.

Background/Aim: Exposure to arsenic during childhood is associated with adverse health problems including cancers and non-cancerous diseases. However, little is known about its effect on vaccine-related humoral immunity in children. In this study, we examined the association between arsenic exposure and measles antibody titers in US children. Methods: The association between urinary arsenic and serum measles antibody levels in the US children aged between 6 and 11 was investigated, based on the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2009-2010. The total urinary arsenic level was calculated by summing inorganic arsenic and their metabolites (arsenite, arsenate, methylarsonic acid, and dimethylarsinic acid), and was divided by the level of urinary creatinine. The generalized linear regression was conducted to evaluate the association, adjusted for the cycle, age, race, undergrowth, secondhand smoking, and poverty index ratio. Stratified analyses were conducted by gender and serum folate levels using the median as cutoff (18.7 ng/mL). Results: The level of serum measles antibody titers decreased by 28.1% (95%CI: −44.2%, −12.0%) per tertile increase in the concentration of creatinine-adjusted urinary arsenic among boys with serum folate levels lower than 18.7 ng/ml. However, no associations were observed in boys with high serum folate levels and girls. Conclusion: Our stratified analysis showed the inverse association between arsenic exposure and measles antibody level among boys with lower folate intake. This study will provide the basis for an intervention strategy to protect children’s health from arsenic exposure.

Characteristics of measles immunity in students of the pediatric faculty of a medical university

Objective: to evaluate the intensity of measles immunity in students of I–VI courses of the pediatric faculty of St. Petersburg State Medical University.Materials and methods: titers of antibodies to measles virus were determined in 986 students of I–VI courses in May –June 2019. The level of measles antibodies was determined by enzyme-linked immunosorbent assay.Results: positive (protective) titres of measles antibodies were detected in 555 people. (56.4%), the absence of measles immunity was found in 431 people. (43.6%), including 57 people. (5.8%) specific antibodies were not detected. The relationship between the level of collective immunity and the duration of the period after the last vaccination against measles was revealed.Conclusions: in the majority of examined students (96.2%), protective titers of measles antibodies remained for 10 years after the last vaccination. Subsequently, a significant decrease in the level of measles antibodies was noted. All students who do not have a protective IgG titer are shown measles vaccination with live measles vaccine in accordance with the instructions for use.

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.

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.

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.

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.