Seroprevalence of measles-, mumps- and rubella-specific IgG antibodies in German children and adolescents and predictors for seronegativity

Measles seroprevalence in Thailand: are adolescents and young adults at risk of measles?

INTRODUCTION

During the last decade, measles has become an important re-emerging disease in Thailand. The objective of this study was to measure measles seroprevalence and its influencing factors so as to plan an improved vaccination programme.

METHODS

A total of 600 participants aged between 9 months and 50 years were divided into seven groups representing birth cohorts that experienced different measles vaccination policies. Participants' blood samples were obtained to measure measles immunoglobulin G (IgG) levels.

RESULTS

None of the participants in the age group of 9 months had measles IgG levels beyond a protective level. Participants in the age groups 2.5, 5-15, 16-29, 30-33, 34-40 and 41-50 years had 82% (95% confidence interval [CI] 73.3-90.7), 50% (95% CI 36.1-63.9), 52% (95% CI 42.3-62.7), 70% (95% CI 61.1-78.9), 88.8% (95% CI 84.1-93.5) and 98.8% (95% CI 96.4-100.0) measles seropositivity, respectively. The study did not find any significant factors affecting measles seropositivity.

CONCLUSION

Individuals aged 15-34 years are vulnerable to measles infections. Supplementary vaccination should be encouraged in special situations, including postexposure prophylaxis for young adults during an outbreak and for high-risk occupations such as healthcare personnel.

Immune Cells, Gut Microbiota, and Vaccines: A Gender Perspective

The development of preventive and therapeutic vaccines has played a crucial role in preventing infections and treating chronic and non-communicable diseases, respectively. For a long time, the influence of sex differences on modifying health and disease has not been addressed in clinical and preclinical studies. The interaction of genetic, epigenetic, and hormonal factors plays a role in the sex-related differences in the epidemiology of diseases, clinical manifestations, and the response to treatment. Moreover, sex is one of the leading factors influencing the gut microbiota composition, which could further explain the different predisposition to diseases in men and women. In the same way, differences between sexes occur also in the immune response to vaccines. This narrative review aims to highlight these differences, focusing on the immune response to vaccines. Comparative data about immune responses, vaccine effectiveness, and side effects are reviewed. Hence, the intricate interplay between sex, immunity, and the gut microbiota will be discussed for its potential role in the response to vaccination. Embracing a sex-oriented perspective in research may improve the efficacy of the immune response and allow the design of tailored vaccine schedules.

The decline of measles antibody titers in previously vaccinated adults: a cross-sectional analysis

The global reemergence of measles in 2018-2019 reinforces the relevance of high-coverage immunization to maintain the disease elimination. During an outbreak in the Sao Paulo State in 2019, several measles cases were reported in individuals who were adequately vaccinated according to the current immunization schedule recommends. This study aimed to assess measles IgG antibody seropositivity and titers in previously vaccinated adults. A cross-sectional study was conducted at CRIE-HC-FMUSP (Sao Paulo, Brazil) in 2019. It included healthy adults who had received two or more Measles-Mumps-Rubella vaccines (MMR) and excluded individuals with immunocompromising conditions. Measles IgG antibodies were measured and compared by ELISA (Euroimmun®) and chemiluminescence (LIASON®). The association of seropositivity and titers with variables of interest (age, sex, profession, previous measles, number of measles-containing vaccine doses, interval between MMR doses, and time elapsed since the last MMR dose) was analyzed. A total of 162 participants were evaluated, predominantly young (median age 30 years), women (69.8%) and healthcare professionals (61.7%). The median interval between MMR doses was 13.2 years, and the median time since the last dose was 10.4 years. The seropositivity rate was 32.7% by ELISA and 75.3% by CLIA, and a strong positive correlation was found between the tests. Multivariate analyses revealed that age and time since the last dose were independently associated with positivity. Despite being a single-center evaluation, our results suggest that measles seropositivity may be lower than expected in adequately immunized adults. Seropositivity was higher among older individuals and those with a shorter time since the last MMR vaccine dose.

Antibody Response against Vaccine Antigens in Children after TCRαβ-Depleted Haploidentical Stem Cell Transplantation: Is It Similar to That in Recipients with Fully Matched Donors?

Recipients of hematopoietic stem cell transplantation (HSCT) with HLA-mismatched donors are more immune suppressed than those with fully matched donors. The immunologic response to vaccines also may differ in HLA-mismatched haploidentical HSCT recipients. In this study, we aimed to evaluate the antibody response to vaccines in pediatric TCRαβ-depleted haploidentical HSCT recipients. This longitudinal study included a study group of 21 children who underwent haploidentical HSCT without CD19 depletion and with TCRαβ depletion and a control group of 38 children who underwent fully matched donor HSCT. Antibody levels were quantified by serologic tests before vaccination and after each dose against tetanus, diphtheria, pneumococcus, hepatitis B, hepatitis A, measles, rubella, mumps, and varicella. The median recipient age was significantly lower (P = .037) and the median donor age was significantly higher (P = .000) in the haploidentical group compared with the fully matched group. At the months 1, 3, 6, 9 and 12 post-transplantation, the median CD4, CD8, and CD19 cell counts and lymphocyte counts were similar in the haploidentical and fully matched groups. The median natural killer cell count was higher in the haploidentical group at the months 1, 3, and 6 post-transplantation (P = .001, .006, and .004, respectively). The median time to first vaccination was similar in the 2 groups (12.5 [range, 11 to 14] months for the haploidentical group and 11 [range, 9 to 13] months for the fully matched group; P = .441). Seroprotection rates were 100% in both groups after the second and third doses of diphtheria vaccine, the third dose of tetanus vaccine, the third dose of hepatitis B vaccine, the second and third doses of pneumococcal conjugate vaccines (PCV13), and pneumococcal polysaccharide vaccine (PSPV23), although lower after the initial doses and before vaccination. Seroprotection for hepatitis A, rubella, and varicella was >90% in the fully matched group and 100% for the haploidentical group after the second doses. Measles and mumps seroprotection rates were >80% in the haploidentical group and approximately 70% for the fully matched group after the second dose. Antibody response and seroprotection rates against vaccine antigens were similar in the haploidentical group and the fully matched when revaccination was started at 12 months post-transplantation. These findings support the idea that TCRαβ-depleted haploidentical HSCT recipients can be revaccinated according to the same vaccination schedule as fully matched HSCT recipients. Revaccination earlier after transplantation and vaccine responses for recipients of different types of HSCT should be evaluated in future studies.

Measles Serostatus in Mothers and Their Newborns in Antioquia, Colombia: Implications for Measles Elimination

To describe the serostatus of measles IgG antibodies in pregnant women and newborns, placental transfer, and factors that determine being below the threshold of 150 mIU/mL, a cross-sectional study was conducted. Blood samples of 790 pregnant women at the time of delivery and 734 umbilical cord samples were analyzed from eight hospitals in the Aburrá Valley of Antioquia, Colombia. Measles IgG antibody measurement was performed with ELISA. The proportion of individuals with antibodies < 150 mIU/mL was 13.9% (95% CI: 12.2-15.8) in pregnant women and 11.1% (95% CI: 9.2-13.4) in newborns. The geometric mean of the antibody level of the pregnant women was 552 mIU/mL (95% CI: 504-605) and in the umbilical cord 662 mIU/mL (95% CI: 604-727). A positive correlation between pregnant woman and umbilical cord antibodies was found. The median ratio of measles IgG antibodies in umbilical cord/pregnant woman was 1.22 for all participants. A seroprevalence below the threshold of 150 mIU/mL was found in newborns whose mothers were born between 1983 and 1994, compared with those born before that period, when exposure to the wildtype virus was common (adjusted prevalence ratio: 3.6, 95% CI: 1.3-9.6). These findings suggest that there are gaps in measles immunity among women of childbearing age, before pregnancy. To close this immune gap and support efforts to maintain measles control, serological screening for measles antibodies should be routinely included in reproductive health and antenatal care programs to identify women without immunity who should be vaccinated before pregnancy or after delivery.

Potential immunological effects of gender-affirming hormone therapy in transgender people - an unexplored area of research

There are well-described sex-based differences in how the immune system operates. In particular, cisgender (cis) females have a more easily activated immune system; associated with an increased prevalence of autoimmune diseases and adverse events following vaccinations. Conversely, cis males have a higher threshold for immune activation, and are more prone to certain infectious diseases, such as coronavirus disease (COVID-19). Oestrogen and testosterone have immune-modulatory properties, and it is likely that these contribute to the sexual dimorphism of the immune system. There are also important immune-related genes located on the X chromosome, such as toll-like receptor (TLR) 7/8; and the mosaic bi-allelic expression of such genes may contribute to the state of immune hyperactivation in cis females. The scientific literature strongly suggests that sex-based differences in the functioning of the immune system are related to both X-linked genes and immune modulation by sex hormones. However, it is currently not clear how this impacts transgender (trans) people receiving gender-affirming hormonal therapy. Moreover, it is estimated that in Australia, at least 2.3% of adolescents identify as trans and/or gender diverse, and referrals to specialist gender-affirming care are increasing each year. Despite the improving social awareness of trans people, they remain chronically underrepresented in the scientific literature. In addition, a small number of case studies describe new onset autoimmune disorders in adult trans females following oestrogen use. However, there is currently minimal long-term research with an immunological focus on trans people. Therefore, to ensure the positive health outcomes of trans people, it is crucial that the role of sex hormones in immune modulation is investigated further.

The Concordance between Mumps and Rubella Sero-Positivity among the Israeli Population in 2015

Mumps and rubella are vaccine-preventable viral diseases through the measles-mumps-rubella-varicella (MMRV) vaccine, administered at 12 months and again at 6 years. We assessed the sero-prevalence of mumps and rubella, identified factors associated with sero-negativity, and evaluated concordance between mumps and rubella sero-positivity. A national cross-sectional sero-survey was conducted on samples collected in 2015 by the Israel National Sera Bank. Samples were tested for mumps and rubella IgG antibodies using an enzyme-linked immunosorbent assay. Of 3131 samples tested for mumps IgG, 84.8% (95%CI: 83.5–86.0%) were sero-positive. Sero-negativity for mumps was significantly associated with age (high odds ratios observed in infants younger than 4 years and 20–29 years old subjects). Of 3169 samples tested for rubella IgG antibodies, 95.2% (95%CI: 94.4–95.9%) were sero-positive. Rubella sero-negativity was significantly associated with age (high odds ratios observed in children younger than 4 years old and adults older than 30 years), males, Jews, and others. Concordant sero-positivity for both mumps and rubella viruses was observed in 83.9% of the tested samples. The Israeli population was sufficiently protected against rubella but not against mumps. Since both components are administered in the MMRV vaccine simultaneously, the mumps component has a lower uptake than rubella and quicker waning.

Molecular identification and characterization of Measles virus genotypes circulating in Afghanistan, 2008-2018

The measles virus remains a leading cause of morbidity and mortality in children under five years of age. Molecular identification of circulating wild-type measles virus (MV) strains is a vital component of the measles elimination program. We received 159 oral swab samples from Afghanistan during 2008-2018. Viral RNA was extracted, followed by one-step RT-PCR and positive amplicons were subject to sequencing for genotype identification. Out of 159 total samples, 52% (83/159) were detected positive by RT-PCR. Genotype D4 was identified from 2.4% (2/83), genotype H1, 4.8% (4/83) and genotype B3, 92.7% (77/83) cases respectively. This article is protected by copyright. All rights reserved.

Measles seroprevalence among Dutch travelling families

BACKGROUND

While measles vaccination is widely implemented in national immunisation programmes, measles incidence rates are increasing worldwide. Dutch inhabitants who were born between 1965-1975 may have fallen between two stools, lacking protection from a natural infection, and having missed the introduction of the measles vaccination schedule. With this study we aim to find the measles seroprevalence in travellers born between 1965 and 1975, compared to those born before 1965 and after 1975.

METHODS

Families travelling to Eastern Europe or outside Europe during the preceding year were recruited via Dutch secondary schools between 2016 and 2018. Their vaccination status was assessed using questionnaires, vaccination records and measles serology in dried blood spot (DBS) eluates. Measles virus antibody concentrations were determined with an ELISA (EUROIMMUNE®) and a subset was retested with a focus reduction neutralization assay (FRNT).

RESULTS

In 188 (79%) of the 239 available DBS eluates, the ELISA could detect sufficient measles virus-specific IgG antibodies. Of the negative samples that were retested with FRNT, 85% remained negative, resulting in an overall seroprevalence of 82% [95% CI 76-86]. Children had a lower seroprevalence (72%) than adults (87%). Travellers born between 1965 and 1975 were protected in 89%.

CONCLUSIONS

In this study, we report a measles seroprevalence of 82% among Dutch travelling families. Remarkably, seroprevalence rates were lowest in children (12-18 years) instead of travellers born between 1965 and 1975. Although a fraction of people without detectable antibodies may be protected by other immune mechanisms, these data suggest that measles (re)vaccination should be considered for travellers to endemic regions.

High seroprevalence of rubella in Thai children with a 2-dose MMR national immunization policy

Rubella is generally a mild disease, but infection during pregnancy can cause congenital rubella syndrome. Thailand has implemented a two-dose MMR vaccination policy since 2010. This study aimed to describe the seroprevalence rate of rubella among children and adolescents in Thailand. We conducted a cross-sectional study of 132 healthy children (aged 3-9 years) who had received 2 doses of rubella vaccine and 424 adolescents (aged 10-18 years) who were expected to receive at least 1 dose of rubella vaccine. Stored serum samples from healthy children and recently drawn serum samples from adolescents were tested for rubella IgG antibody using a commercial enzyme-linked immunosorbent assay (ELISA) kit (EUROIMMUN). Seroprotection was defined as a rubella IgG level ≥ 10 IU/mL. The rubella seroprevalence rate among children and adolescents who had 2 documented doses of MMR was 97.0% (95 %CI 92.5-99.2%) and 85.4% (95% CI 78.8-90.6%, p < 0.01) respectively. The geometric mean titer of rubella was higher in children, 38.3 (95% CI 33.5-43.9) compared to adolescents, 22.5 (19.4-25.9) IU/mL. We observed an inverse correlation between the rubella titer and time interval from the second rubella containing vaccine dose (R = -0.30, p < 0.01). A 2-dose MMR vaccination course produces a high seroprevalence of rubella immunity in children, which decreases with time, suggesting waning of immunity. Thai clinical trials registry number TCTR20191120001.

Chronic Myeloid Leukemia in Children: Immune Function and Vaccinations

Children with CML need TKI treatment for many years, and the lack of knowledge about immune dysfunction with TKI has hindered routine immunizations. This review attempts to provide an overview of the effects of TKIs licensed for children (e.g., imatinib, dasatinib, and nilotinib) on immune function, as well as its implications on immunizations. We discuss surveillance strategies (e.g., immunoglobulin blood serum levels and hepatitis B reactivation) and immunizations. All inactivated vaccines (e.g., influenza, pneumococcal, and streptococcal) can be given during the treatment of CML in the chronic phase, although their efficacy may be lower. As shown in single cases of children and adults with CML, live vaccines (e.g., varicella, measles, mumps, rubella, and yellow fever) may be administered under defined circumstances with great precautions. We also highlight important aspects of COVID-19 in this patient population (e.g., the outcome of COVID-19 infection in adults with CML and in children with varying hemato-oncological diseases) and discuss the highly dynamic field of presently available different vaccination options. In conclusion, TKI treatment for CML causes humoral and cellular immune dysfunction, which is mild in most patients, and thus infectious complications are rare. Routine immunizations are important for health maintenance of children, but vaccinations for children with CML on TKI therapy should be carefully considered.

Seroprevalence of Measles-, Mumps-, and Rubella-specific antibodies in the German adult population - cross-sectional analysis of the German Health Interview and Examination Survey for Adults (DEGS1)

BACKGROUND

The WHO European Region targets the elimination of measles, rubella, and the congenital rubella syndrome and welcomes mumps elimination via the joint MMR vaccine. In a push towards this elimination goal, Germany introduced a recommendation on MMR vaccination for adults in 2010 to prevent increasing numbers of measles cases among adults and to strengthen herd immunity.

METHODS

The prevalence of anti-measles, -mumps, and -rubella IgG antibodies was analysed in 7,115 participants between the ages of 18 and 79 years in the German Health Interview and Examination Survey. Risk factors of seronegativity of adults born 1970 or later were determined.

FINDINGS

The seroprevalence of anti-measles IgG antibodies was more than 97% in adults born before 1965 and less than 90% in adults born afterwards. Prevalence and GMTs declined with later years of birth. Seronegativity was associated with two-sided migration background and region of residence in East Germany. For anti-mumps IgG antibodies, the seroprevalence was less than 90% in almost all age groups. Prevalence and GMTs declined with later years of birth. Seronegativity was not associated with any socio-demographic factor. Anti-rubella IgG seropositivity was found in more than 90% of adults born before 1985. GMTs declined in younger age groups. Seronegativity was associated with birth between 1980 and 1993 and male gender. High socio-economic status lowered the odds of being seronegative.

INTERPRETATION

These data reinforce the implementation of the vaccination recommendation for adults and provide the basis for further evaluation of this measure.

FUNDING

The Federal Ministry of Health, Germany.

Early childhood vaccination coverage and timeliness by macro-area of origin in children born to foreign women residing in Italy

OBJECTIVES

Country of origin might affect vaccine uptake in children born to immigrants. We aimed to evaluate differences in childhood vaccination coverage (VC) and timeliness by macro-area of origin of foreign mothers residing in Italy.

STUDY DESIGN

Multicentre retrospective birth cohorts.

METHODS

We analysed data of 23,287 children born in 2009-2014 to foreign women in the cities of Rome, Turin and Treviso. We retrieved data through record-linkage of the population, vaccination and birth registries. We estimated VCs at different ages for vaccines against tetanus, measles and meningococcal group-C, using the Kaplan-Meier method. Factors associated with vaccine uptake were evaluated using multilevel Poisson models.

RESULTS

Estimates of VC at any age and for all antigens were significantly lower in children born to women from Asia and higher in children born to women from Africa, as compared to other macro-areas. Similar differences by area of origin were observed for timeliness; independently of mother's sociodemographic characteristics and neonatal outcomes, the probability of delay vaccination after 2 years of age for each antigen was highest in children born to women from Asia. The risk of missed vaccination for all antigens was significantly higher in children born to younger and unemployed women.

CONCLUSIONS

Factors related to area of origin (e.g., cultural habits, language skills) are likely to affect parents' decision to vaccinate their children. These factors, as well as sociodemographic characteristics, should be adequately investigated and addressed to increase vaccine uptake in foreign children, especially those born to Asian women.

Gender Differences in the Level of Antibodies to Measles Virus in Adults

Individuals without a protective antibody level are susceptible to measles infection. There are differences in the persistence of antibodies after vaccination and infection, while the impact of gender on this process has not been sufficiently studied. Measles Ig G antibodies were measured in 1742 employees of a large hospital facility-403 men and 1339 women aged from 25 to 67 years; 15% participants had antibody levels less than the protective threshold of ≥0.18 IU/mL. Significant differences were found in the age group 40-49, where the level of IgG antibodies to measles among men was higher than among women (1.51 IU/mL (0.41; 3.38) vs. 0.70 IU/mL (0.22;1.98) respectively, (U = 3.2, p = 0,001)); in the age group 60 and older, by contrast, the level of antibodies among women was higher compared to men (3.29 IU/mL (1.72; 4.07) vs. 2.90 IU/mL (1.46; 3.53) respectively (U = 2.2, p = 0.03)). The proportion of seronegative women in the age group 40-49 was significantly higher than of seronegative men: 22 [18-26]% and 11 [6-18]% respectively (χ2 = 7.0, p = 0.001). The revealed gender characteristics that affect persistence of measles immunity may be important in personalization of vaccinal prevention for men and women.

Effect of early measles vaccination on long-term protection: A systematic review

BACKGROUND

In North America, the first dose of a measles-containing vaccine (MCV1) is administered at ≥12 months of age. However, MCV1 may be given to infants <12 months living in highly endemic areas or traveling to these areas. Although an early dose of MCV1 leads to immediate protection, it remains unclear how this impacts long-term immunity.

METHODS

This systematic review and meta-analysis evaluates the impact of MCV1 given at <12 months vs. ≥12 months of age on long-term immunogenicity and vaccine effectiveness, with long-term defined as at least one-year post-vaccination. PubMed, EMBASE, Global Health, Web of Science and Scopus were searched on October 31st, 2019. Studies were included if they included a cohort of infants vaccinated <12 months of age and evaluated long-term immunogenicity, vaccine efficacy, or effectiveness.

RESULTS

A total of 51 texts were identified: 23 reported outcomes related to vaccine effectiveness and 30 to immunogenicity. Infants vaccinated with MCV1 < 12 months of age showed an overall higher risk of measles compared to ≥12 months of age (RR = 3.16, 95% CI: 2.00, 5.01; OR = 2.46, 95% CI: 1.40, 4.32). Risk of measles decreased with increasing age at first vaccination, with those vaccinated with one dose ≥15 months at a lesser risk compared to 12-14 months or <12 months. Measles seroconversion and seropositivity was not affected by age at first vaccination, but antibody levels were significantly lower in the MCV1 < 12-month group (MD = -0.40, 95% CI: -0.71, -0.09).

CONCLUSION

Long-term measles seroconversion and seropositivity did not appear to be affected by age at MCV1, while vaccine effectiveness decreased with younger age. There was not enough evidence to look at the effect of age at MCV1 on immune blunting.

Sero-survey of measles virus antibodies among symptomatic children attending Abuja Teaching Hospital, Nigeria

Background: Nigeria is one of the countries with a high prevalence of measles outbreak in children under 5 years old, despite a history of vaccination. This study aims to determine the prevalence of anti-measles virus IgM and IgG among children under 5 years attending the University of Abuja Teaching Hospital (UATH), Gwagwalada, FCT Abuja, Nigeria.

Materials and methods: Whole blood was collected, centrifuged, and serum anti-IgM and anti-IgG against measles virus was analysed using ELISA. Sociodemographic variables and vaccination history of subjects were obtained by interview-based questionnaires.

Results: The overall anti-Measles virus IgG and IgM seroprevalences were 29.2% and 14.6%, respectively. The prevalence of measles IgG was significantly associated with the parent’s employment status (X²=11.67, p=0.008). However, the prevalence of measles virus IgM was significantly associated with children’s age (X²=16.62, p=0.002), parents’ employment status and children’s vaccination status (X² =7.72, p=0.02).

Conclusion: A majority of study participants were not immunised against measles, and a significant number of participants had serological evidence of acute measles virus infection. There is a need for more concerted and massive measles vaccination of children.

Seroprevalence against the measles virus after vaccination or natural infection in an adult population in Madinah, Saudi Arabia

Background: Over the past few years, measles cases have increased worldwide, despite the availability of a safe and highly effective vaccine. Numerous countries have eliminated measles or have made substantial advancements toward elimination.Materials and Methods: This study investigated the seroprevalence of anti-measles antibodies and vaccination status among 362 men and 81 women in Madinah. All participants were vaccinated or acquired immunity naturally due to infection. We aimed to examine the persistence of anti-measles IgG antibodies, which were qualitatively and quantitatively determined using ELISA.Results: We showed that measles seropositivity (92%, n = 408) was significantly more frequent than negative (5.4%, n = 14) and equivocal results (2.5%, n = 11). Among men, 92.8% were seropositive for the anti-measles IgG antibody, whereas 88.9% of women were seropositive. In addition, a significant relationship was observed between age and measles seropositivity, with a significant positive correlation between age and anti-measles antibody concentration as assessed by Spearman's correlation analysis (r = 0.405, p < .001).Conclusion: Based on these results, observing the serological status of the population 20-38 y after vaccination may be necessary to minimize the proportion of individuals who may be vulnerable to contracting measles. Despite the efficacy of the measles, mumps, and rubella vaccine and the positive global impact associated with the use of this vaccine, including a general decline in measles cases, attention must still be paid to the issue of measles risk, and seronegative individuals should be identified and advised to receive a booster dose of the vaccine.

Determination of ELISA reactive mumps IgG antibodies in MMR vaccine recipients in comparison with MMR vaccine naive children: A cross sectional study

Background/Aim: Mumps is by vaccine preventable infectious disease characterised by parotitis. In India mumps vaccines are not currently used under National Immunisation Programme (NIP). Waning of vaccine-induced immunity is considered to play a central role in the re-emergence of mumps. The comprehensive data on the seroepidemiology of measles, mumps, and rubella (MMR) as well as studies which compare the antibody titre among mumps vaccine naiveand mumps vaccinated children are lacking. The aim of this study was to estimate and compare mumps specific antibody titre in children with and without MMR vaccine. Methods: In 2019/2020, blood samples were collected from 100 healthy children attending immunisation clinic in Government Medical College Kota and associated J K Lon Maternal and Child care hospital Kota. The samples were investigated for MMR IgG antibodies using ELISA. Results: Out of total 100 children included in the study, 32.27 % vaccinated and 4.83 % non-vaccinated children were positive for mumps IgG antibody in the age group of 6 months to 6 years of age. Children aged 6 to 12 years, vaccinated and non-vaccinated, had 31.57 % and 26.57 % positivity, respectively. The seroprevalence of measles, mumps and rubella antibodies among 50 MMR vaccinated children were 94 %, 64 %, and 96 %, respectively. A high measles and rubella seroprevalences were observed among all children age groups, suggesting an effective control program, while the mumps seroprevalence decreased significantly with age. Conclusion: The maximum vaccine effectiveness against mumps for 2 doses of MMR vaccine is ≈ 96 %. The herd immunity threshold to block mumps virus transmission is ≥ 86 %. In this study only 64 % of the vaccinated children were found to have IgG mumps antibodies. In view of morbidity following mumps infection there is a need to incorporate mumps vaccine along with measles and rubella vaccine in the NIP instead of Mr.

Rubella seroprevalence using residual samples from the South African measles surveillance program: a cross-sectional analytic study

Introduction: South Africa is yet to introduce rubella-containing vaccines (RCV) into its routine immunization schedule. Selecting the target population when introducing RCV should take into account the ages of susceptible individuals in the population. We aimed to determine the seroprevalence of antibodies to rubella and characterize immunity gaps among individuals of all ages in South Africa. Methods: We tested for rubella immunoglobulin G (IgG) antibodies with a commercial enzyme-linked immunosorbent assay. We used residual samples collected from 2016 through 2018 as part of the national measles surveillance program. We only tested samples that were negative for measles and rubella immunoglobulin M (IgM) and explored the association between rubella susceptibility (IgG negative) and predictor variables (year of sample collection, age, sex, and province of residence) using logistic regression analysis. Results: We obtained results for 6057 records. Rubella susceptibility was highest among Individuals aged zero to 11 months (81.9%), followed by children 1 to 5 years old (71.5%), 6 to 10 y old (40.9%) and 11 to 15 y old (31.25) while the smallest proportion of susceptible individuals was among those 16 to 49 y old (19.9%). Females were less likely to be susceptible to rubella compared to males (OR = 0.79 (95%CI: 0.71-0.87), P < .001) in unadjusted analysis but this effect was not observed after adjusting for age and province. In multivariable logistic regression, age (OR = 6.24 (4.52-8.63), P < .001) and province of residence (OR = 0.97 (95%CI: 0.95-0.99), P = .01) were associated with rubella susceptibility. Conclusion: In the absence of rubella vaccination in the Expanded Program on Immunization in South Africa, the bulk of individuals susceptible to rubella are children under 16 y old. About 20% of individuals 16 to 49 y old are susceptible to rubella. This susceptibility gap must be born in mind during RCV introduction.

Humoral responses to the measles, mumps and rubella vaccine are impaired in Leigh Syndrome French Canadian patients

Leigh Syndrome French Canadian (LSFC) is a rare autosomal recessive metabolic disorder characterized by severe lactic acidosis crises and early mortality. LSFC patients carry mutations in the Leucine Rich Pentatricopeptide Repeat Containing (LRPPRC) gene, which lead to defects in the respiratory chain complexes and mitochondrial dysfunction. Mitochondrial respiration modulates cellular metabolic activity, which impacts many cell types including the differentiation and function of immune cells. Hence, we postulated that, in addition to neurological and metabolic disorders, LSFC patients may show impaired immune activity. To gain insight into the quality of the immune response in LSFC patients, we examined the response to the measles, mumps and rubella (MMR) vaccine by measuring antibody titers to MMR in the plasma. In a cohort of eight LSFC patients, the response to the MMR vaccine was variable, with some individuals showing antibodies to all three viruses, while others had antibodies to two or fewer viruses. These results suggest that the mutations in the LRPPRC gene present in LSFC patients may affect the immune response to vaccines. Monitoring vaccine response in this fragile population should be considered to ensure full protection against pathogens.

Mumps Outbreaks in Vaccinated Populations-Is It Time to Re-assess the Clinical Efficacy of Vaccines?

History illustrates the remarkable public health impact of mass vaccination, by dramatically improving life expectancy and reducing the burden of infectious diseases and co-morbidities worldwide. It has been perceived that if an individual adhered to the MMR vaccine schedule that immunity to mumps virus (MuV) would be lifelong. Recent mumps outbreaks in individuals who had received two doses of the Measles Mumps Rubella (MMR) vaccine has challenged the efficacy of the MMR vaccine. However, clinical symptoms, complications, viral shedding and transmission associated with mumps infection has been shown to be reduced in vaccinated individuals, demonstrating a benefit of this vaccine. Therefore, the question of what constitutes a good mumps vaccine and how its impact is assessed in this modern era remains to be addressed. Epidemiology of the individuals most affected by the outbreaks (predominantly young adults) and variance in the circulating MuV genotype have been well-described alluding to a collection of influences such as vaccine hesitancy, heterogeneous vaccine uptake, primary, and/or secondary vaccine failures. This review aims to discuss in detail the interplay of factors thought to be contributing to the current mumps outbreaks seen in highly vaccinated populations. In addition, how mumps diagnoses has progressed and impacted the understanding of mumps infection since a mumps vaccine was first developed, the limitations of current laboratory tests in confirming protection in vaccinated individuals and how vaccine effectiveness is quantified are also considered. By highlighting knowledge gaps within this area, this state-of-the-art review proposes a change of perspective regarding the impact of a vaccine in a highly vaccinated population from a clinical, diagnostic and public perspective, highlighting a need for a paradigm shift on what is considered vaccine immunity.

Measles immunity gaps in an era of high vaccination coverage: A serology study from Taiwan

BACKGROUND

Routine vaccination for children drastically reduces measles cases. Nonetheless, the global resurgence of measles since 2018 highlights the need for evaluating vaccine-induced immunity in an era of high vaccination coverage, especially in international travelers. This study aims to identify high-risk persons via analyzing the impact of age and different vaccination schedules on seroprevalence of measles in a country with high vaccination coverage, attempting to provide suggestions regarding pre-travel measles vaccination in highly immunized countries.

METHOD

We retrospectively collected serological results of measles from Taiwanese travelers during 2008-2017 and middle-aged subjects from community during 2007-2009. Participants were classified by age groups and cohort based on the national immunization program: cohort I (pre-mass vaccination), cohort II (suboptimal measles vaccination), and cohort III (2-dose MMR in childhood). The effects of age group on seropositivity was shown by odds ratio (OR) with 95% confidence interval (CI) in a logistic regression model.

RESULTS

The overall measles seroprevalence was 74.5% (N = 1096, mean age = 31.7 ± 12.3 years), with adolescents having the lowest seropositivity (65.9%) and participants ≥50 years having the highest (89.4%). Seropositivity was significantly higher in cohort I (pre-mass vaccination) compared with the other 2 cohorts (P < 0.0001). The effect of aging on seropositivity was only significant in cohort II (OR = 1.84, 95% CI = 1.13-2.99, P = 0.014 for 30-39 years vs. 20-29 years).

CONCLUSIONS

Waning immunity to measles in adolescents and young adults is a dominant issue in highly vaccinated cohorts. Enhancing pre-travel vaccination against measles can effectively fill the immunity gaps in highly immunized countries.

Ecological inference for infectious disease data, with application to vaccination strategies

Disease surveillance systems provide a rich source of data regarding infectious diseases, aggregated across geographical regions. The analysis of such ecological data is fraught with difficulties, and, unless care and suitable data summaries are available, will lead to biased estimates of individual-level parameters. We consider using surveillance data to study the impacts of vaccination. To catalog the problems of ecological inference, we start with an individual-level model, which contains familiar parameters, and derive an ecologically consistent model for infectious diseases in partially vaccinated populations. We compare with other popular model classes and highlight deficiencies. We explore the properties of the new model through simulation and demonstrate that, under standard assumptions, the ecological model provides less biased estimates. We then fit the new model to data collected on measles outbreaks in Germany from 2005-2007.

Seroepidemiological study of rubella in Vojvodina, Serbia: 24 years after the introduction of the MMR vaccine in the national immunization programme

Although rubella is usually a mild childhood disease, this infection in early pregnancy poses a serious problem due to its teratogenic effect. The goal of interrupted circulation and elimination of rubella virus was achieved in many countries in the world. The aim of this study was to determine the status of rubella immunity in Vojvodina and evaluate Serbia's progress toward this goal. A total of 3404 residual serum samples from patients of all ages (1 to 84 years) were included in the study. Samples were collected between May 2015 and December 2017 in Vojvodina. Rubella IgG antibodies were determined using an indirect chemiluminescent immunoassay. Percentage of participants seropositive for rubella antibodies was 92.9% in the entire sample. The highest number of seronegatives was in the youngest (1 year) age group (44.7%), followed by the group aged 24-49 (6.4%) and 2-11 years (6.2%). The absence of a higher percentage of children with protective anti-rubella antibodies in the group aged 2-11 can be explained by a lower immunization coverage during certain years. Participants in the group aged 24-49 were born during the pre-vaccination period with lower rubella incidence, leading to the conclusion that not all individuals of that age came into a contact with the virus. Comparing levels of anti-rubella IgG antibodies of seropositive males and females of different ages reveals that the immunity after a contact with the virus and a previously acquired infection is stronger than the immunity after the vaccination. Although the incidence rate of rubella in Vojvodina has been low for the last ten years, there is still a risk of an outbreak due to a decrease in immunization coverage. This study shows that the percentage of susceptible individuals is high, especially considering women aged 24-49, and that additional ("catch-up") immunization is required.

Assessment of immune status against measles, mumps, and rubella in young Kuwaitis: MMR vaccine efficacy

Seroprevalence studies on measles, mumps, and rubella immunoglobulin G (IgG) antibodies after the implementation of the measles-mumps-rubella (MMR) vaccine are lacking in Kuwait. This study is an age-stratified serological study to assess the herd immunity to measles, mumps, and rubella among the young Kuwaiti population to evaluate the effectiveness of the MMR vaccine. IgG antibody titers to mumps, measles, and rubella were determined with commercial immune-assay in serum samples of 1000 Kuwaitis aged 5 to 20 years. The highest level of seropositivity was to measles (94.6%), which was significantly higher in females than in males. The highest seronegativity was for mumps (29%). The percentage of the young Kuwaiti population who were serologically positive for all the components of the MMR vaccine was 47%, and 2% of the individuals were without any protective antibodies to measles, mumps, and rubella. Females aged 5 to 10 years were best protected to rubella; however, seronegativity in 8.2% of 11- to 20-year-old females makes them vulnerable to rubella virus infection and congenital complications during pregnancy. The study provided insight into the effect of the MMR vaccine on seroprevalence of antibodies against measles, mumps, and rubella in Kuwait, which will contribute to the global knowledge base of vaccine coverage and help to inform elimination strategies. The findings strengthen the need for a third dose of MMR vaccine and catch-up campaigns for the young Kuwaiti population to increase vaccination coverage and prevent waning immunity, especially among those who received only one dose of the vaccine during childhood.

Seroprevalence of vaccine-preventable diseases among children and adolescents in Singapore: Results from the National Paediatric Seroprevalence Survey 2018

OBJECTIVES

The Ministry of Health (MOH), Singapore, conducted the National Paediatric Seroprevalence Survey 2018 (NPSS 2018) to estimate the latest immunity levels against measles, rubella, varicella, diphtheria, tetanus and hepatitis B, and the seroprevalence of chronic hepatitis B virus (HBV) carriage in children and adolescents in Singapore.

METHODS

The survey involved prospective collection of residual sera from 1,200 children and adolescents aged 1-17 years in two public acute hospitals. Enzyme-linked immunosorbent assays (EIA) or plague reduction neutralisation tests (PRNT) were used to determine the seroprevalence of the vaccine-preventable diseases.

RESULTS

Overall prevalence of measles and rubella antibodies among Singaporean children and adolescents aged 1-17 years were 98.2% (95% CI: 91.2-98.8%) and 94.8% (95% CI: 93.4-95.9%) respectively. 97.1% (95% CI: 96.0-97.9%) of subjects had at least basic protection against diphtheria, while 89.3% (95% CI: 87.5-91.0%) were protected against tetanus. The prevalence of chronic HBV carriage was 0.4% (95% CI: 0.2-1.0%), while 45.7% (95% CI: 42.9-48.5%) were immune against HBV. The seroprevalence for varicella antibodies was 52.9% (95% CI: 50.1-55.7%). Concordance between vaccination status and seroprevalence was observed for measles, rubella, diphtheria and tetanus.

CONCLUSION

Singapore's children and adolescents are well-protected against measles, rubella, diphtheria and tetanus. Continual efforts in ensuring high vaccination coverage should be sustained.

Seroprevalence of mumps before the introduction of mumps-containing vaccine in Lao PDR: results from a nationwide cross-sectional population-based survey

OBJECTIVE

Mumps-containing vaccine is currently not a component of the national immunization schedule in Lao People's Democratic Republic (PDR). Mumps itself is not a notifiable disease in the country and the seroprevalence of anti-mumps immunoglobulin G (IgG) in the general population is unknown. In this study, anti-mumps IgG was measured in 2058 blood samples to evaluate population immunity in the country.

RESULTS

The seroprevalence of anti-mumps IgG showed a gradual increase with increasing age, starting at 10.6% (95% CI 7.4-13.7) in participants aged 1-2 years, and almost plateaued at about 75% in individuals older than 11-12 years, though it still tended toward a small increase up to 89.6% (95% CI 86.6-92.6) in participants aged 40 years or older. Compared with the results of previous studies, this increase with increasing age is less marked and the plateau of anti-mumps seroprevalence is lower. We attribute this result mainly to the lower population density in Lao PDR.

Comparison of early childhood vaccination coverage and timeliness between children born to Italian women and those born to foreign women residing in Italy: A multi-centre retrospective cohort study

BACKGROUND

Compared to hosting populations, immigrants are usually considered more vulnerable to communicable diseases, many of which are vaccine-preventable. This study aims to estimate vaccination coverage (VC) and timeliness in children born to women from high migratory pressure countries (HMPC) and to evaluate factors affecting differences with children born to Italian women or women from advanced development countries (ITA + ADC).

METHODS

We retrospectively analysed data of children born in 2009-2014 and resident in areas served by three local health units in the cities of Rome (n = 40,284), Turin (n = 49,600), and Treviso (n = 20,080). Data were retrieved through record-linkage of the population, vaccination, and birth registries. We used the Kaplan-Meier method to estimate VCs at different ages for the 3rd dose of vaccine against tetanus and the 1st dose of vaccines against measles and meningococcal group C. Factors affecting differences in VCs by citizenship were evaluated using log-binomial models.

RESULTS

In Rome, VCs at 2 years of age were consistently higher in children born to ITA + ADC women than in children born to HMPC women, while differences in VCs by citizenship varied according to antigen and birth-cohort in Turin and Treviso, respectively. Where differences were observed, these were only partially explained by the mother's socio-demographic characteristics, level of utilisation of health-services during pregnancy, and maternal, perinatal, and neonatal outcomes. Finally, we observed a reduction of VCs in recent birth cohorts (2012-14 vs. 2009-11), especially in children born to ITA + ADC women.

CONCLUSIONS

Differences in VCs by citizenship were not homogeneous and varied according to geographical context, antigen, and birth-cohort. These differences are likely to be also affected by informal barriers (e.g., linguistic and cultural barriers), which should be addressed in implementing strategies to increase vaccine uptake in foreign children. Moreover, our results suggest that effective strategies to promote vaccinations in the autochthonous population are also needed.

Seroprevalence of measles, mumps & rubella antibodies among 5-10 years old children in north India

Background & objectives

: Globally, there is an effort to eliminate the measles and control rubella as these diseases lead to considerable morbidity and mortality especially among under-five children and are important public health problems. This study was aimed to estimate the seroprevalence of measles, mumps and rubella (MMR) antibodies among children of age 5-10 yr in Chandigarh, north India, to provide evidence on prevalent immunity levels.

Methods

: This cross-sectional study was conducted in Chandigarh, among 196 randomly selected healthy children (5-10 yr), who received either one or two doses of measles or MMR combination vaccine. Socio-economic background and immunization history were recorded. Blood sample (2 ml) was collected to estimate the MMR IgG antibody titres by using ELISA kits.

Results

: Protective seroprevalence of MMR antibodies was 40.8, 75.5 and 86.2 per cent, respectively. The geometric mean titres of MMR IgG antibodies in the study children were 11.3, 50.6 and 54.3 international units (IU)/ ml, respectively. The proportion of seroprotected children for measles was significantly higher among those who had received two or more doses (46.4%) of measles vaccine compared to those who had received single dose (35.6%) (P <0.001). About 16 per cent of children had received single dose of MMR vaccine. Among these, 71.4 and 100 per cent were seroprotected against mumps and rubella, respectively.

Interpretation & conclusions

: A large proportion of children aged 5-10 yr lacked protective immunity against measles (60%); about one-fourth (15-25%) were susceptible to infection with mumps and rubella virus. Mumps vaccination may be considered to be included in National Immunization Schedule for children with periodic serosurveillance.

Seroprevalence of measles, mumps, rubella, and varicella zoster virus antibodies among healthcare students: analysis of vaccine efficacy and cost-effectiveness

OBJECTIVE

The aims of this study are to determine the seroprevalence for measles, mumps, rubella, and varicella zoster virus (VZV) in a cohort of nursing students, to evaluate vaccination response rates of nonimmune students, and to calculate the cost of vaccinating students based on seroprevalence screening.

METHODS

A cross-sectional study was conducted August 2015-November 2016 among 326 healthy nursing students aged 14.1-18.1 years. Serum IgG antibodies were measured by ELISA. Results were analyzed by the Chi-square test; a p-value of < 0.05 was considered statistically significant.

RESULTS

The number of seropositive participants (%) was 308 (94.5%) for rubella, 295 (90.5%) for VZV, 244 (74.9%) for measles, and 219 (67.2%) for mumps. A significant correlation was found between measles IgG and age. A relationship was also observed between VZV IgG and kindergarten attendance. Response rates to measles, rubella, VZV, and mumps vaccination were 96%, 92.3%, 87.5%, 78.8%, respectively. The total cost of vaccination after IgG screening was less than vaccination without screening.

CONCLUSIONS

In this study, participants' immunity to measles and VZV was low. Prevaccination serological screening was cost-effectiveness method for preventing measles, mumps, rubella, and varicella infections. We believe that administering booster measles, mumps, and rubella (MMR) vaccine doses or developing a special MMR vaccination strategy for at-risk groups may prevent MMR outbreaks.

Sex differences in vaccine-induced humoral immunity

Vaccines are among the most impactful public health interventions, preventing millions of new infections and deaths annually worldwide. However, emerging data suggest that vaccines may not protect all populations equally. Specifically, studies analyzing variation in vaccine-induced immunity have pointed to the critical impact of genetics, the environment, nutrition, the microbiome, and sex in influencing vaccine responsiveness. The significant contribution of sex to modulating vaccine-induced immunity has gained attention over the last years. Specifically, females typically develop higher antibody responses and experience more adverse events following vaccination than males. This enhanced immune reactogenicity among females is thought to render females more resistant to infectious diseases, but conversely also contribute to higher incidence of autoimmunity among women. Dissection of mechanisms which underlie sex differences in vaccine-induced immunity has implicated hormonal, genetic, and microbiota differences across males and females. This review will highlight the importance of sex-dependent differences in vaccine-induced immunity and specifically will address the role of sex as a modulator of humoral immunity, key to long-term pathogen-specific protection.

Effect of A Sun Protection Intervention on the Immune Response to Measles Booster Vaccination in Infants in Rural South Africa

The incidence of many serious childhood infections can be reduced by vaccination. High sun exposure at the time of vaccination has been associated with a reduced antigen-specific immune response. We hypothesized that providing sun protection advice and equipment to mothers of children who were waiting to be vaccinated would result in a more robust immunization response. We conducted a pilot study in 2015/2016 (data analyzed in 2017-2018) among 98 Black African children (~18 months of age) receiving the booster measles vaccination at two clinics in South Africa. Clinics were randomized to receive (or not) sun protection advice and equipment. We recorded demographic information on children and mothers and data on the child's usual sun exposure. At approximately 4 weeks' postmeasles vaccination, we measured measles immunoglobulin G levels in children. All children with blood results (n = 87, 89%) across both groups had antibody titers higher than 200 mIU mL^-1 which was considered the protective antibody concentration. There was no statistically significant difference in titers between groups: geometric difference in mean titers 1.13 mIU mL^-1 (95% CI 0.85, 1.51; P = 0.39) and 1.38 mIU mL^-1 (95% CI 0.90, 2.11, P = 0.14) for unadjusted and adjusted analyses, respectively. This study demonstrated that a sun protection intervention study could be performed in a developing-world pediatric vaccination setting. Although the sun protection intervention around the time of vaccination was not associated with a higher antibody level, given the potential importance of such an effect, a larger study should be considered.

Epidemiological and molecular investigation of a measles outbreak in Punjab, Pakistan, 2013-2015

Despite the availability of an effective vaccine, the measles virus continues to cause significant morbidity and mortality in children worldwide. Molecular characterization of wild-type measles strains is an invaluable component of epidemiological studies or surveillance systems that provides important information pertinent to outbreak linkages and transmission pathways. Serum samples and throat swabs were collected from suspected measles cases from the Punjab province of Pakistan (2013-2015) and further tested for measles immunoglobulin M (IgM) through enzyme-linked immunosorbent assay and reverse-transcriptase polymerase chain reaction for molecular characterization. Among the total of 5415 blood samples, 59% tested positive for measles IgM. Males had a higher infection rate (55%) than females (45%), and the highest frequency of positive cases (63%) was found in the age group of 0 to 5 years. Partial sequencing of the nucleoprotein gene showed that 27 strains belonged to the B3 genotype, whereas 2 viruses were identified as D4. On phylogenetic analysis, Pakistani B3 strains were found to be closely related to previously reported indigenous strains and those from neighboring countries of Iran and Qatar. This is the first report on the detection of the measles B3 genotype from Punjab, Pakistan. The current study shows a high burden of measles infections in Punjab province owing to poor routine immunization coverage in major cities. It is imperative that national health authorities adopt strategic steps on an urgent basis for improvement of routine immunization coverage. Molecular epidemiology of the measles viruses circulating in different parts of the country can provide useful data to manage future outbreaks.

Public health response to a measles outbreak on a university campus in Australia, 2015

This report describes the effective public health response to a measles outbreak involving a university campus in Brisbane, Australia. Eleven cases in total were notified, mostly university students. The public health response included targeted measles vaccination clinics which were established on campus and focused on student groups most likely to have been exposed. The size of the university population, social interaction between students on and off campus, as well as limited vaccination records for the university community presented challenges for the control of this extremely infectious illness. We recommend domestic students ensure vaccinations are current prior to matriculation. Immunisation information should be included in university student enrolment packs. Incoming international students should ensure routine vaccinations are up-to-date prior to arrival in Australia, thereby reducing the risk of importation of measles and other infectious diseases.

Serological survey of mumps antibodies in adults in the Czech Republic and the need for changes to the vaccination strategy

Mumps outbreaks, especially in adolescents and young adults, have been reported in the Czech Republic. The aim of the presented study was to determine the seroprevalence of specific IgG antibodies against mumps in the adult population of the Czech Republic. The study was designed as a multicenter serological survey of adults aged 18 years and over. Specific IgG antibodies against mumps were detected in blood samples using an enzyme-linked immunosorbent assay (ELISA). A total of 1,911 serum samples were examined. The overall seropositivity reached 55.3%. In individual age groups, the highest seropositivity 63% (63.5-65.2%) was recorded in adults aged 40 years and over; the lowest seropositivity was found in adults aged 18-29 years (27.4%). The difference in seropositivity rate between the 18-29 years age group and the 40 years and over age groups was statistically significant (p < 0.001). Only the 18-29 years age group included both vaccinated and unvaccinated (born in the pre-vaccine era) individuals. In vaccinated individuals, seropositivity was reported in only 19.1% of persons; in unvaccinated individuals, seropositivity reached 48.2%. Our results demonstrate the long-term persistence of antibodies following natural infection and the decrease in seropositivity that occurs after vaccination over time. This immunity waning may account for the higher susceptibility of adolescents and young adults to mumps. Therefore, the current vaccination program in the Czech Republic could be considered as less effective. It will be modified with the shifting of the second dose of vaccine from two years of age to the preschool age.

IgG antibody prevalence suggests high immunization needs in newcomers to Luxembourg, 2012

Vaccine coverage of the general population in Luxembourg is high, but refugees or asylum seekers may be incompletely vaccinated and susceptible to vaccine-preventable diseases. In order to assess protection rates, serum and oral fluid samples were collected from 406 newcomers aged between 13 and 70 years arriving between May and September 2012. Sera were screened for IgG antibodies against measles, rubella, mumps, hepatitis B, tetanus, diphtheria and pertussis. Oral fluid samples were screened for antibodies against measles, mumps and rubella virus to investigate their suitability for antibody prevalence studies. More than 90% of the participants had IgG antibodies against rubella, 73% against measles and 56% against mumps. Less than 19% had anti-HBs antibodies. Nearly 84% of the participants had an adequate protection against tetanus, 73% against diphtheria and 40% had pertussis antibodies. 93%, 95% and 78% of the measles, rubella and mumps test results obtained with serum and oral fluid were concordant. The majority of the participants lacked antibodies against at least one of the measles/mumps/rubella (58%) and diphtheria/tetanus/pertussis (72%) vaccine components and against hepatitis B virus (82%) and might thus profit from vaccination. Oral fluid is a suitable alternative and non-invasive specimen for measles/rubella antibody prevalence studies.

Low intrathecal antibody production despite high seroprevalence of Epstein-Barr virus in multiple sclerosis: a review of the literature

BACKGROUND

Patients with multiple sclerosis (MS) frequently have an intrathecal production of antibodies to different common viruses, which can be detected by elevated antiviral antibody indices (AIs). There is a strong and consistent association of MS and Epstein-Barr virus (EBV) infection.

OBJECTIVE

To systematically compare the frequencies of intrathecal antibody production to EBV, measles virus, rubella virus, varicella zoster virus (VZV) and herpes simplex virus (HSV) in patients with MS.

METHODS

Review of the English and German literature on the frequencies of intrathecal immunoglobulin (Ig)G antibody production, as defined by an elevated AI, to EBV, measles virus, rubella virus, VZV and HSV in adult and pediatric patients with MS.

RESULTS

In nine original studies identified, the frequencies of an intrathecal production of antibodies to Epstein-Barr nuclear antigen-1 (33/340, 9.7%), EBV viral capsid antigen (12/279, 4.3%) and antigens from EBV-infected cell lines (14/90, 15.6%) in adult patients with MS were clearly lower (p ≤ 0.03 for all pairwise comparisons) than the frequencies of an intrathecal production of antibodies to measles virus (612/922, 66.4%), rubella virus (521/922, 56.5%), VZV (470/922, 51%; data from 17 original studies) and HSV (78/291, 26.8%; data from 6 original studies). Though based on a lower number of original studies and patients, findings in children with MS were essentially similar. As in adults and children with MS the seroprevalence of EBV is higher than the seroprevalences of the other investigated viruses, the lower frequency of elevated EBV AIs became even more pronounced after correction of the frequencies of elevated antiviral AIs for the seroprevalences of the respective viruses.

CONCLUSIONS

Given the very high seroprevalence of EBV in MS, the frequency of intrathecally produced antibodies to EBV in patients with MS is paradoxically low compared to that of other common viruses. These findings are compatible with the recently proposed hypothesis that in individuals going on to develop MS antiviral antibody-producing cells may invade the brain predominantly at the time of and triggered by acute primary EBV infection, before anti-EBV IgG producing cells have yet occurred.

Comparison of rubella immunization rates in immigrant and Italian women of childbearing age: Results from the Italian behavioral surveillance system PASSI (2011-2015)

Background

International migration rapidly increased in the last decade, raising a renewed attention to its impact on public health. We evaluated differences in rubella immunization rate (RIR) between immigrant and Italian women of childbearing age and tried to identify the driving factors causing them.

Methods

We analyzed data from the Italian behavioral surveillance system PASSI collected in 2011–2015 in a nationally representative sample of residents in Italy. The analysis was performed using log-binomial models to compare RIR between 41,094 Italian women and 3140 regular immigrant women of childbearing age (18–49 years), stratifying the latter by area of origin and length-of-stay in Italy (recent: ≤ 5-years; mid-term: 6-10-years; long-term: > 10-years).

Results

Immigrant women showed a RIR of 36.0% compared to 60.2% among Italian women (RIR-ratio = 0.60, 95% confidence interval (CI): 0.57–0.63). Adjusting for demographic characteristics (i.e., sex, age and area of residence), socio-economic factors (i.e., education, occupation, family composition and economic status) and an indicator of the presence of at least one health-risk behavior (i.e., physical inactivity, current cigarette smoking, excessive alcohol consumption and excess weight) did not significantly change this difference (RIR-ratio = 0.56, 95% CI: 0.53–0.59). Recent immigrants (RIR-ratio = 0.47, 95% CI: 0.42–0.53) and immigrants from high migratory pressure countries (HMPC) in sub-Saharan Africa (RIR-ratio = 0.41, 95% CI: 0.31–0.56) and Asia (RIR-ratio = 0.42, 95% CI: 0.33–0.53) showed the greatest differences in RIR compared with Italian women.

Conclusions

Differences in RIR between immigrant and Italian women were not explained by different demographic, socioeconomic and health-risk behaviors characteristics. As entitlement to free-of-charge immunization in Italy is universal, regardless of migration status, other informal barriers (e.g., cultural and barriers to information access) might explain lower RIRs in immigrant women, especially recent immigrants and those from HMPC in sub-Saharan Africa and Asia. Further investigations are needed to identify obstacles and appropriate promotion and access-enabling strategies for rubella immunization.

Reduced Antibody Response to Infant Measles Vaccination: Effects Based on Type and Timing of the First Vaccine Dose Persist After the Second Dose

Background

The effect of age at first dose on the immunogenicity of a 2-dose pediatric schedule of measles-mumps-rubella (MMR) or measles-mumps-rubella-varicella (MMRV) vaccine was assessed in children born to mostly vaccinated mothers.

Methods

Immunogenicity data among children given their first measles vaccine dose between 11 and 22 months of age were pooled from 5 randomized controlled trials conducted in Europe and the United States between 2004 and 2010. Measles antibody titers were measured by enzyme-linked immunosorbent assay before and after each dose; geometric mean concentrations (GMCs) and the proportion seronegative (GMC <150 mIU/mL) were derived by age at first dose.

Results

Among 5542 children given a first measles vaccine dose at 11, 12, 13-14, and 15-22 months of age, the proportion seronegative decreased from 8.5% to 3.2%, 2.4%, and 1.5%, respectively (P < .001), whereas GMCs increased with older age measles vaccine initiation (P < .001). MMRV induced higher GMCs than MMR (P < .001). First and second dose GMCs were highly correlated (Spearman coefficient = 0.8).

Conclusions

As previously noted among infants born to mothers with history of wild-type measles, antibody responses among children born to vaccinated mothers were reduced based on earlier administration of their first measles vaccine dose at ≤12 vs ≥15 months of age. Negative effects of earlier age at first measles vaccine dose persisted after the second dose. The measles elimination goal may require a careful balance between earlier infant protection and the risk of reduced antibody responses and secondary vaccine failure among successive birth cohorts systematically initiated to measles vaccination <15 months of age.

Maternal HIV infection associated with reduced transplacental transfer of measles antibodies and increased susceptibility to disease

BACKGROUND

Transplacental transfer of measles antibodies from mother to fetus is important in protecting against measles during early infancy. Changes in population immunity against measles in adults, including waning of immunity among HIV-infected pregnant women, could affect passive immunity acquired in utero by newborns.

OBJECTIVES

To evaluate the effect of maternal HIV infection on transplacental transfer of measles antibody in mother-newborn dyads in a setting of high maternal HIV prevalence.

STUDY DESIGN

Serum at birth was obtained from 303 mother-newborn dyads, including 196 HIV-infected and 107 HIV-uninfected women, and tested for measles IgG antibodies by ELISA. Seronegativity was defined as antibody levels <150mIU/ml and seroprotective titers as ≥330mIU/ml.

RESULTS

HIV-infected and -uninfected women had similar measles antibody titers, however, cord-blood titers were lower among HIV-exposed (788.06mIU/ml) compared to HIV- unexposed newborns (1306.6mIU/ml; p≤0.001), due to lower transplacental antibody transfer ratio in HIV-exposed (0.63) than in HIV-unexposed newborns (0.97; p≤0.001). Maternal age <25years of age was associated with lower antibody titers and lower percentage with seroprotective titer, as well as less likelihood of their newborns having seroprotective titers (70.2% vs. 86.5%; p=0.001).

CONCLUSIONS

Lower levels of measles antibody in HIV-exposed newborns and in younger women <25years old, increases the susceptibility of their newborns to developing measles. This suggest a need to re-evaluate measles immunization of women of child bearing age and the timing of measles vaccination among infants in settings with a high prevalence of maternal HIV-infection.

Seroprevalence of Measles Antibodies and Predictors for Seropositivity among Chinese Children

Background: Supplementary measles immunization has been implemented since 2010 throughout China, yet few studies have reported its effect in the northwest regions. Methods: A cross-sectional study was conducted among children aged 2 to 4 years old (n = 755) from February to September 2014 in 25 towns of Qian County, Shaanxi Province. Blood samples were analyzed for measles antibodies using enzyme-linked immunosorbent immunoglobulin G (IgG) assays. Socio-demographic factors were assessed by questionnaire. Data on vaccine dose were collected from town medical records. Univariate and logistic regression analyses were used to determine factors associated with measles antibody seropositivity. Results: Measles antibody seroprevalence was 91.13% (95% CI: 89.52-92.83) in our sample. Compared with children whose mother's highest education was primary school, seroprevalence was higher in children whose maternal education was middle school (adjusted OR: 1.4, 95% CI: 0.7-2.8), high school (adjusted OR: 2.4, 95% CI: 1.3-7.7), and college/university (adjusted OR: 2.9, 95% CI: 1.2-9.3). Vaccine dose was positively associated with seropositivity. Conclusions: Measles seroprevalence is high in China and is associated with the mother's education and vaccine dose.

Decreasing Seroprevalence of Measles Antibodies after Vaccination - Possible Gap in Measles Protection in Adults in the Czech Republic

Aims

In recent years, Europe has recorded an increase in the number of measles outbreaks despite the implementation of vaccination into the National Immunization Programs. The Czech Republic introduced vaccination against measles into National Immunization Program in 1969. The aim of this study was to determine seroprevalence of IgG antibodies against measles in adults.

Methods

Our study was designed as a prospective, multicenter cohort study. Samples of blood were taken from adults aged 18 years and over. Specific IgG antibodies were determined by ELISA method.

Results

A number of 1911 sera samples were obtained. The total seropositivity reached 83.3%, 14.3% of the results were negative and 2.4% were borderline. When comparing the individual age groups, the highest antibody seropositivity (> 96%) was detected in persons aged 50 years and over who were naturally infected in pre-vaccine era. The lowest seropositivity was recorded in the age groups 30–39 years (61.5%), 40–49 years (77.5%) and 18–29 years (81.1%).

Conclusions

A long term high rate of seropositivity persists after natural measles infection. By contrast, it decreases over time after vaccination. Similarly, the concentrations of antibodies in persons with measles history persist for a longer time at a higher level than in vaccinated persons. Our results indicate possible gap in measles protection in adults born after implementation of vaccination into the National Immunization Programs. There are two probable reasons, decrease of measles antibody seropositivity in time after vaccination in setting of limited natural booster and one-dose vaccination schedule used in the first years after implementation.

Serological assessment of the establishment of herd immunity against measles in a health district in Malaysia

Background

Malaysia still faces challenges optimizing resources to effectively eliminate measles through high immunization and herd immunity, with sporadic outbreaks of measles as evidence. The objective of this study is to determine the age-specific positive measles antibodies seroprevalence used for assessing the establishment of herd immunity against measles in different age groups. This is useful for identifying vulnerable age groups requiring supplementary immunization.

Methods

A seroprevalence study was conducted among respondents aged 6–9 years, 15–24 years and 45–54 years attending government health clinics in Seremban between September 2014 and January 2015. A total of 1541 measles IgG antibody status were determined using ELISA technique (NovaTec Immundiagnostica GMBH) and assessment of establishment of herd immunity was based on indicators developed by Plans. Data on socio-demographic background as well as medical and medication history were also gathered.

Results

Seropositive rate for all respondents were 87% (95% CI 85–89), while the rest had either indeterminate [6% (95% CI 5–7)] or negative titre [7% (95% CI 6–8)]. None of the factors analyzed except for age were significant predictors of positive measles antibodies. Seropositive rate differed by age with the highest rate seen in adults (94%; CI 92–96), followed by children (90%; 95% CI 87–94) and adolescents, and young adults (74%; 95% CI 70–78). Based on Plans’ indicators, herd immunity was established in adults and children, but not in adolescents and young adults.

Conclusions

To tackle the most susceptible group in the present study, it is advisable to give booster vaccination to secondary school students and freshmen who enter colleges and universities in Malaysia.

Vaccination in secondary school students expedites rubella control and prevents congenital rubella syndrome

Background

In order to control the spread of rubella and reduce the risk for congenital rubella syndrome, an additional rubella vaccination program was set up for all secondary school students since 2008 in Zhejiang, China.

Methods

We conducted a descriptive analysis of rubella incidence among different age groups from 2005 to 2015 and a serosurvey of female subjects aged 15–39 years to understand the possible effects of this immunization program.

Results

The average annual rubella incidence rate had decreased from 15.86 per 100,000 population (2005–2007) to 0.75 per 100,000 population (2013–2015) in Zhejiang. The decrease in the rate of rubella incidence in girls aged 15–19 years was more accelerated (from 138.30 to 0.34 per 100,000) than in the total population during 2008–2015 (from 32.20 to 0.46 per 100,000). Of 1225 female subjects in the serosurvey, 256 (20.9%) were not immune to rubella. The proportion of subjects immune to rubella was significantly different among different age groups (Wald χ2 = 22.19, p = 0.000), and subjects aged 15–19 years old had the highest immunity (88.0%). Rubella antibody levels were significantly lower in women aged 25–30 years with 26.7% of them not immune, followed by the group aged 20–24 years (25.0%) and 30–35 years (24.5%).

Conclusions

Rubella vaccine included in the Expanded Program on Immunization together with vaccination activities for secondary school students can help in rubella control, particularly in targeted age groups in the program. Seroprevalence of antibodies to the rubella virus amongst the female population within childbearing age in Zhejiang, China, is still too low to provide immunity. In addition to vaccination programs in the secondary schools, rubella vaccination should also be encouraged in women of childbearing age, which can be done effectively combined with pre-marital examination in China.

Differences in Influenza Vaccination Coverage between Adult Immigrants and Italian Citizens at Risk for Influenza-Related Complications: A Cross-Sectional Study

BACKGROUND

Due to their increased vulnerability, immigrants are considered a priority group for communicable disease prevention and control in Europe. This study aims to compare influenza vaccination coverage (IVC) between regular immigrants and Italian citizens at risk for its complications and evaluate factors affecting differences.

METHODS

Based on data collected by the National Institute of Statistics during a population-based cross-sectional survey conducted in Italy in 2012-2013, we analysed information on 42,048 adult residents (≥ 18 years) at risk for influenza-related complications and with free access to vaccination (elderly residents ≥ 65 years and residents with specific chronic diseases). We compared IVC between 885 regular immigrants and 41,163 Italian citizens using log-binomial models and stratifying immigrants by area of origin and length of stay in Italy (recent: < 10 years; long-term: ≥ 10 years).

RESULTS

IVC among all immigrants was 16.9% compared to 40.2% among Italian citizens (vaccination coverage ratio (VCR) = 0.42, 95% confidence interval (CI): 0.36-0.49). Adjusting for sex, age and area of residence, this difference was greatly reduced but remained statistically significant (VCR = 0.71, 95 CI: 0.61-0.81). Further adjustment for socio-economic factors (education, occupation, family composition and economic status) and a composite indicator of health-services utilization did not affect the difference (VCR = 0.78, 95% CI: 0.68-0.90). However, after adjustments, only long-term immigrants from Africa (VCR = 0.49, 95% CI: 0.28-0.85) and recent immigrants (VCR = 0.58, 95% CI: 0.43-0.78) showed a significantly different IVC compared to Italian citizens.

CONCLUSIONS

Differences in demographic characteristics, socio-economic conditions and health-services utilization explained the reduced IVC in most long-term immigrants compared to Italian citizens. By contrast, these differences did not explain the reduced IVC in long-term immigrants from Africa and recent immigrants. This suggests that IVC in these sub-groups is affected by other informal barriers (e.g., cultural and linguistic) that need to be investigated to promote effective immunization access strategies.

Mumps, measles and rubella vaccination in children with PFAPA syndrome

There is no published data regarding immunologic response to vaccinations in children with PFAPA syndrome (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis). The aim of this study was to evaluate mumps, measles and rubella immunity in children with PFAPA. 31 children with PFAPA syndrome and 22 healthy children (control group - CG) were recruited to the study. All children were previously vaccinated with one dose of MMR vaccine according to the Polish obligatory vaccination schedule. The patients from both groups were evaluated for anti-measles, anti-mumps and anti-rubella IgG antibodies concentrations (ELISA tests; the reference values for protective antibody levels were 150IU/L, 16RU/L and 11IU/ml respectively). The percentage of patients with protective antibodies levels was as follows: measles - 93.55% of PFAPA and 95.45% of CG patients (p=0.77); mumps - 74.19% of PFAPA and 95.45% of CG patients (p=0.02); rubella - 80.65% of PFAPA and 90.9% of CG patients (p=0.30).

CONCLUSIONS

Children with PFAPA syndrome present a good response to the measles and rubella component of the MMR vaccine, however immunity against mumps after one dose of MMR may not be sufficient. Further investigation concerning immunity against vaccine-preventable diseases and the safety of vaccinations in children with periodic fever syndromes is required.