Seroprevalence of measles, mumps, rubella and varicella antibodies in the United States population, 2009-2010

Serological investigation of vaccine-induced antibodies for measles, rubella, and yellow fever viruses in children vertically exposed to Zika virus or with down syndrome

Background

Vaccination schedules, as well as their effectiveness and contraindications, need to be evaluated regularly, especially in specific situations. Congenital Zika Syndrome (CZS) is a severe condition that results in extensive functional and neurological impairment of fetuses and newborns due to Zika virus tropism for fetal neural progenitor cells. Down Syndrome (DS) is the leading genetic cause of intellectual disability. The immune impairment in DS has already been described, but little is known about the immune response of CZS children. Thus, CZS and DS are specific conditions that can be considered for a reassessment of the available immunizations. Here, we carried out serological analyses of attenuated vaccines-induced antibodies for measles, rubella, and yellow fever viruses in children aged 2-7, grouped into asymptomatic controls, DS children, and CZS children.

Methods

Plasma samples were taken, and vaccination records were compiled during clinical follow-up. Enzymatic immunoassays for quantifying anti-measles and anti-rubella IgG were performed to assess the response to the Measles, Mumps, and Rubella (MMR) vaccine. Plaque Reduction Neutralization Test (PRNT) was performed to investigate neutralizing antibodies in response to the Brazilian vaccine strain of yellow fever (YF-17DD).

Results

We highlight similar levels of anti-measles IgG and neutralizing antibodies for YF-17DD among CZS, DS, and asymptomatic children, although low positivity of measles data was seen in the three groups. In DS children, the 2-4-year-old group had an increased level of anti-measles IgG compared to the older group of children aged five to seven years. Lower anti-rubella IgG levels were observed in CZS and DS children compared to asymptomatic children. For anti-rubella IgG, the good performance of vaccination in asymptomatic children is due to younger ones rather than older ones.

Conclusions

There were no reports of adverse events after the use of the MMR and YF-17DD indicating that CZS and DS could continue to receive these vaccines, but our data draws attention to the necessity of monitoring the vaccination response in CZS and DS children over time and the possible need to adhere to national measles vaccination campaigns. Scientific research needs to continue to help develop appropriate CZS and DS health guidelines.

Seroprevalence of Measles, Mumps, Rubella, and Varicella-Zoster Virus and Seroresponse to the Vaccinations in Adult Solid Organ Transplant Candidates

BACKGROUND

Updating live vaccines such as measles, mumps, rubella, and varicella (MMRV) is an important step in preparing patients for solid organ transplant (SOT) to prevent morbidity from these preventable diseases. However, data for this approach are scarce. Thus, we aimed to describe the seroprevalence of MMRV and the efficacy of the vaccines in our transplant center.

METHODS

Pre-SOT candidates >18 y of age were retrospectively retrieved from SOT database in Memorial Hermann Hospital Texas Medical Center. MMRV serologies are routinely screened at the time of pretransplant evaluation. We divided patients into 2 groups: MMRV-positive group versus MMRV-negative group, patients with positive all MMRV serologies and with negative immunity to at least 1 dose of MMRV, respectively.

RESULTS

A total of 1213 patients were identified. Three hundred ninety-four patients (32.4%) did not have immunity to at least 1 dose of MMRV. Multivariate analysis was conducted. Older age (odds ratio [OR]: 1.04) and liver transplant candidates (OR: 1.71) were associated with seropositivity. Previous history of SOT (OR: 0.54) and pancreas/kidney transplant candidates (OR: 0.24) were associated with seronegativity. Among 394 MMRV seronegative patients, 60 patients received 1 dose of MMR vaccine and 14 patients received 1 dose of varicella-zoster virus vaccine without severe adverse events. A total of 35% (13/37) of patients who had follow-up serologies did not have a serological response.

CONCLUSIONS

A significant number of pre-SOT candidates were not immune to at least 1 dose of MMRV. This highlights the importance of MMRV screening and vaccinations pre-SOT. Postvaccination serological confirmation should be performed to evaluate the necessity for a second dose.

Systematic review and meta-analysis of epidemiologic data on vaccine response in relation to exposure to five principal perfluoroalkyl substances

BACKGROUND

Epidemiologic studies of serum per- and polyfluoroalkyl substances (PFAS) and antibody response to vaccines have suggested an adverse association, but the consistency and magnitude of this association remain unclear.

OBJECTIVE

The goal of this systematic review was to determine the size of the association between a doubling in perfluoroalkyl substances (PFAS) serum concentration and difference in log_e antibody concentration following a vaccine, with a focus on five PFAS: perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA).

DATA SOURCE

We conducted online searches of PubMed and Web of Science through May 17, 2022 and identified 14 eligible reports published from 2012 to 2022.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

We included studies conducted in humans, including mother-child pairs, which examined serum PFAS concentration in relation to serum concentration of antibody to a specific antigen following a vaccine.

STUDY APPRAISAL AND SYNTHESIS METHODS

We used the risk of bias assessment for non-randomized studies of exposure and certainty assessment method proposed by Morgan et al. (2019). Using a multilevel meta-regression model, we quantitatively synthesized the data.

RESULTS

The 14 reports represented 13 unique groups of subjects; the frequency of studies of a given antibody was Tetanus (n = 7); followed by Diphtheria (6); Measles (4); Rubella (3); Haemophilus influenzae type b and Influenza A H1N1 (2 each); and Hepatitis A, Hepatitis B, Influenza A H2N3, Influenza B, and Mumps (1 each). There were approximately 4,830 unique participants included in the analyses across the 14 reports. The models of coefficients between antibody concentration and the five principal PFAS showed homogeneity of associations across antibody types for each principal PFAS. In the models with all antibodies treated as one type, evidence of effect modification by life stage was present for PFOA and PFOS, and for consistency, all associations were evaluated for all ages and for children. The summary associations (coefficients for difference in log_e[antibody concentration] per doubling of serum PFAS) with 95% confidence intervals that excluded zero ("statistical support"), and certainty of evidence ratings were as follows: for PFOA and all antibodies treated as one type in all ages, -0.06 (-0.10, -0.01; moderate) and in children, -0.10 (-0.16, -0.03; moderate); for Diphtheria in children, -0.12 (-0.23, -0.00; high); for Rubella in all ages, -0.09 (-0.17, -0.01; moderate), and for Tetanus in children, -0.12 (-0.24, -0.00; moderate). For PFOS the summary associations were, for all antibodies treated as one type in all ages, -0.06 (-0.11, -0.01; moderate) and in children, -0.10 (-0.18, -0.03; moderate); for Rubella in all ages, -0.09 (-0.15, -0.03; high) and in children, -0.12 (-0.20, -0.04; high). For PFHxS the summary associations were, for all antibodies treated as one type in all ages, -0.03 (-0.06, -0.00; moderate) and in children, -0.05 (-0.09, -0.00; low); and for Rubella in children, -0.07 (-0.11, -0.02; high). Summary associations for PFNA and PFDA did not have statistical support, but all PFAS studied tended to have an inverse association with antibody concentrations.

LIMITATIONS AND CONCLUSIONS

Epidemiologic data on immunosuppression and five principal PFAS suggest an association, with support across antibodies against multiple types of antigens. Data on Diphtheria, Rubella, and Tetanus were more supportive of an association than for other antibodies, and support was greater for associations with PFOA, PFOS, and PFHxS, than for PFNA or PFDA. The data on any specific antibody were scarce. Confounding factors that might account for the relation were not identified. Nearly all studies evaluated were judged to have a low or moderate risk of bias.

Preexisting immunity: Barrier or bridge to effective oncolytic virus therapy?

Oncolytic viruses (OVs) represent a highly promising treatment strategy for a wide range of cancers, by mediating both the direct killing of tumor cells as well as mobilization of antitumor immune responses. As many OVs circulate in the human population, preexisting OV-specific immune responses are prevalent. Indeed, neutralizing antibodies (NAbs) are abundantly present in the human population for commonly used OVs, such as Adenovirus type 5 (Ad5), Herpes Simplex Virus-1 (HSV-1), Vaccinia virus, Measles virus, and Reovirus. This review discusses (pre)clinical evidence regarding the effect of preexisting immunity against OVs on two distinct aspects of OV therapy; OV infection and spread, as well as the immune response induced upon OV therapy. Combined, this review provides evidence that consideration of preexisting immunity is crucial in realizing the full potential of the highly promising therapeutic implementation of OVs. Future investigation of current gaps in knowledge highlighted in this review should yield a more complete understanding of this topic, ultimately allowing for better and more personalized OV therapies.

Rational selection of an ideal oncolytic virus to address current limitations in clinical translation

Oncolytic virus therapy (OVT) is a promising modality that leverages the propensity of natural or engineered viruses to selectively replicate in and kill cancer cells. Over the past decade, (pre)clinical studies have focused on the development and testing of adenovirus, herpes simplex virus, and vaccinia virus-based vectors. These studies have identified barriers to success confronting the field. Here, we propose a set of selection criteria or ideal properties of a successful oncolytic virus, which include lack of pathogenicity, low seroprevalence, selectivity (infection and replication), transgene carrying capacity, and genome stability. We use these requirements to analyze the oncolytic virus landscape, and then identify a potentially optimal species for platform development - vesicular stomatitis virus.

Health and Economic Impact of the United States Varicella Vaccination Program, 1996-2020

BACKGROUND

The aim of this study was to evaluate the health and economic impact of the varicella vaccination program on varicella disease in the United States (US), 1996-2020.

METHODS

Analysis was conducted using the Centers for Disease Control and Prevention or published annual population-based varicella incidence, and varicella-associated hospitalization, outpatient visit, and mortality rates in the US population aged 0-49 years during 1996-2020 (range, 199.5-214.2 million persons) compared to before vaccination (1990-1994). Disease costs were estimated using the societal perspective. Vaccination program costs included costs of vaccine, administration, postvaccination adverse events, and travel and work time lost to obtain vaccination. All costs were adjusted to 2020 US dollars using a 3% annual discount rate. The main outcome measures were the number of varicella-associated cases, hospitalizations, hospitalization days, and premature deaths prevented; life-years saved; and net societal savings from the US varicella vaccination program.

RESULTS

Among US persons aged 0-49 years, during 1996-2020, it is estimated that more than 91 million varicella cases, 238 000 hospitalizations, 1.1 million hospitalization days, and almost 2000 deaths were prevented and 118 000 life-years were saved by the varicella vaccination program, at net societal savings of $23.4 billion.

CONCLUSIONS

Varicella vaccination has resulted in substantial disease prevention and societal savings for the US over 25 years of program implementation.

Prevention and Control of Nosocomial Varicella During the United States Varicella Vaccination Program Era

The United States varicella vaccination program has successfully reduced varicella incidence and hospitalizations by ≥90%, consequently reducing the risk of nosocomial exposures. However, patients and healthcare personnel (HCP) continue to introduce varicella zoster virus (VZV) into healthcare settings. Herpes zoster (HZ) is less contagious than varicella, but it can also result in exposures. Unrecognized varicella and HZ may lead to extensive contact investigations, control efforts, and HCP furloughs that result in significant disruption of healthcare activities as well as substantial costs. Robust occupational health and infection prevention programs that ensure healthcare personnel immunity and prompt recognition and isolation of patients with varicella or HZ will lower the risk of VZV transmission and reduce or eliminate the need to furlough exposed HCP and associated costs.

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.

Risk Factors for Measles Nonimmunity in Rubella-Immune Pregnant Patients

OBJECTIVES

 Measles immunity testing, unlike that for rubella, is not currently part of prenatal screening even though immunity to both is conferred by the measles-mumps-rubella (MMR) vaccine. Although endemic transmission of measles was declared eliminated in the United States in 2001, outbreaks have continued to occur. Given the risks associated with measles infection during pregnancy, we sought to identify risk factors for measles nonimmunity (MNI) in rubella-immune (RI) pregnant individuals.

METHODS

 We performed a retrospective observational cross-sectional study of patients receiving prenatal care and delivering at two university hospitals and a county hospital in Southern California from April 1, 2019 to February 1, 2021. Inclusion criteria were pregnant individuals ≥18 years old who had serological testing for rubella and measles during pregnancy. Demographic data were extracted from electronic medical records, including results of serological testing and chronic medical conditions. All subjects were rubella immune, and we compared measles-immune (MI) with MNI groups.

RESULTS

 In total, 1,813 RI individuals were identified, with 1,467 (81%) MI and 346 (19%) MNI individuals. Variables associated with an increased risk of MNI included having public health insurance (adjusted relative risk [aRR]: 1.56; 95% confidence interval [CI]: 1.24, 1.97) and Hispanic ethnicity (aRR: 1.37; 95% CI: 1.06, 1.78). Black race was associated with a decreased risk of MNI (aRR: 0.52; 95% CI: 0.29, 0.91). Birth year before 1989 demonstrated a trend toward increased risk of MNI, but this did not reach statistical significance (aRR 1.23; 95% CI: 1.00, 1.52). No differences were seen between the two groups for medical comorbidities.

CONCLUSION

 Our study is the first to demonstrate risk factors for measles MNI in patients with documented rubella immunity. In the absence of universal measles serological screening recommendations, the risk factors identified could help guide clinicians in selective screening for those at risk of needing postpartum MMR vaccination.

KEY POINTS

· The rate of measles nonimmunity is higher than previously reported.. · Hispanic ethnicity and use of public insurance are risk factors for measles nonimmunity.. · The current recommendation for history-based screening for measles immunity is likely insufficient..

Seroprevalence of viral infectious diseases and associated factors in Korean patients with inflammatory bowel diseases

BACKGROUND/AIMS

Data on the immunoprotective status against measles, mumps, rubella, varicella zoster virus (VZV), hepatitis A virus (HAV), and Epstein-Barr virus (EBV) infection in patients with inflammatory bowel disease (IBD) are still lacking. Therefore, we investigated the seropositivity rates for viral infectious diseases and the associated factors in Korean patients with IBD.

METHODS

In this retrospective cohort study, serum immunoglobulin G antibody positivity rates against measles virus, mumps virus, rubella virus, VZV, HAV, and EBV viral capsid antigen (VCA) were measured in patients with Crohn's disease or ulcerative colitis (UC) who first visited the IBD clinic. Seropositivity rates and their associated factors were analyzed.

RESULTS

Between January 2016 and December 2018, 263 patients were enrolled (male, 167 [67.3%]; UC, 134 [50.9%]). The median age at serological test was 30 years (interquartile range, 22 to 46). The seropositivity rates were 84.0%, 85.2%, 66.5%, 87.4%, 50.0%, and 93.7% for measles, mumps, rubella, VZV, HAV, and EBV, respectively. Younger age at serological test was associated with seronegative status for measles (adjusted odds ratio [aOR], 0.92; 95% confidence interval [CI], 0.88 to 0.96), VZV (aOR, 0.83; 95% CI, 0.74 to 0.93), and HAV (aOR, 0.93; 95% CI, 0.91 to 0.95). Furthermore, IBD type-UC was associated with seronegative status against VZV (aOR, 0.33; 95% CI, 0.11 to 0.99).

CONCLUSION

Seropositivity rates for common viral infectious diseases in Korean patients with IBD were similar to those of the general population. In the younger age group, protective immunity against measles, VZV, and HAV is required, with proper vaccination, as necessary.

Seroprevalence of Measles and Mumps Antibodies Among Individuals With Cancer

Importance

Although patients with cancer are at an increased risk of infection-related complications, few studies have characterized their vulnerability to measles and mumps. Given the recent outbreaks and increased community vaccine hesitancy, understanding measles and mumps immunity within this population is vital.

Objectives

To identify a point prevalence estimate of protective measles and mumps antibodies among ambulatory patients with cancer.

Design, Setting, and Participants

In this cross-sectional study, residual clinical plasma samples were obtained from consecutive patients with cancer at Seattle Cancer Care Alliance/Fred Hutchinson Cancer Research Center in Seattle, Washington, in August 2019. These samples were tested for measles and mumps IgG using a commercial enzyme-linked immunosorbent assay. Patients without cancer were excluded from the analysis.

Exposures

Patient age, sex, self-reported race and ethnicity, primary disease, receipt of chemotherapy in the past 30 days before sample collection, hematopoietic cell transplant (HCT) history, and date of most recent intravenous immunoglobulin treatment were abstracted from electronic medical records.

Main Outcomes and Measures

Measles and mumps IgG seroprevalence, defined as the proportion of patients with positive antibody test results, was measured overall and among the subgroups.

Results

Of the 959 patients included in the analysis, 510 (53%) were male individuals and the mean (SD) age at sample collection was 60 (15) years. Most patients (576 [60%]) had a malignant solid tumor, and 383 patients (40%) had a hematologic malignant neoplasm; 146 patients (15%) had an HCT history. Overall, the seroprevalence of measles antibodies was 0.75 (95% CI, 0.72-0.78), and the seroprevalence of mumps antibodies was 0.62 (95% CI, 0.59-0.65). The lowest seroprevalences were among patients with a hematologic malignant neoplasm (0.63 for measles and 0.48 for mumps), those with a history of HCT (0.46 for measles and 0.29 for mumps), and those aged 30 to 59 years (0.49-0.63 for measles and 0.41-0.58 for mumps).

Conclusions and Relevance

In this study, 25% of ambulatory patients with cancer lacked protective antibodies for measles and 38% lacked protective antibodies for mumps. Deficits in protective antibodies underscore patients' increased risk during outbreaks and emphasize the need for community-based efforts to increase herd immunity to protect this population.

Antibodies against vaccine-preventable infections after CAR-T cell therapy for B cell malignancies

BACKGROUND

Little is known about pathogen-specific humoral immunity after chimeric antigen receptor–modified T (CAR-T) cell therapy for B cell malignancies.

METHODS

We conducted a prospective cross-sectional study of CD19-targeted or B cell maturation antigen–targeted (BCMA-targeted) CAR-T cell therapy recipients at least 6 months posttreatment and in remission. We measured pathogen-specific IgG against 12 vaccine-preventable infections and the number of viral and bacterial epitopes to which IgG was detected (“epitope hits”) using a serological profiling assay. The primary outcome was the proportion of participants with IgG levels above a threshold correlated with seroprotection for vaccine-preventable infections.

RESULTS

We enrolled 65 children and adults a median of 20 months after CD19- (n = 54) or BCMA- (n = 11) CAR-T cell therapy. Among 30 adults without IgG replacement therapy (IGRT) in the prior 16 weeks, 27 (90%) had hypogammaglobulinemia. These individuals had seroprotection to a median of 67% (IQR, 59%–73%) of tested infections. Proportions of participants with seroprotection per pathogen were comparable to population-based studies, but most individuals lacked seroprotection to specific pathogens. Compared with CD19-CAR-T cell recipients, BCMA-CAR-T cell recipients were half as likely to have seroprotection (prevalence ratio, 0.47; 95% CI, 0.18–1.25) and had fewer pathogen-specific epitope hits (mean difference, –90 epitope hits; 95% CI, –157 to –22).

CONCLUSION

Seroprotection for vaccine-preventable infections in adult CD19-CAR-T cell recipients was comparable to the general population. BCMA-CAR-T cell recipients had fewer pathogen-specific antibodies. Deficits in both groups support the need for vaccine and immunoglobulin replacement therapy studies.

FUNDING

Swiss National Science Foundation (Early Postdoc Mobility grant P2BSP3_188162), NIH/National Cancer Institute (NIH/NCI) (U01CA247548 and P01CA018029), NIH/NCI Cancer Center Support Grants (P30CA0087-48 and P30CA015704-44), American Society for Transplantation and Cellular Therapy, and Juno Therapeutics/BMS.

In this prospective study, we investigated antibodies against vaccine-preventable infections and other pathogen-specific antibodies in individuals with remission after CAR-T cell therapy for B lineage malignancies.

Risk of Absence of Measles Antibody in Healthcare Personnel and Efficacy of Booster Vaccination

We aimed to identify the presence of the measles IgG antibody (mIgG-Ab) in healthcare personnel and finding out who needs the measles vaccination. The history of measles vaccination was obtained from the national vaccine registry. A baseline mIgG-Ab test was performed, and the measles vaccine was administered to participants who tested negative or equivocal for mIgG-Abs. During the study, 2885 (87.3%) of the 3303 employees were tested for measles serostatus. The baseline seropositivity rate for mIgG-Abs was 91.9%. Among the 234 seronegative cases, 82.9% were born after 1985. The seroprevalence rate was lower in those who received the measles–mumps–rubella (MMR) vaccine >10 years before the testing time, especially if they were born after 1985 and if there was only one previous record of vaccination. Among the 234 seronegative cases, MMR vaccination was administered in 174 cases, of which serostatus was evaluated in 146 cases. After the first dose, positive seroconversion was achieved in 126 participants (86.3%). After a second dose, 15 achieved (75.0%) positive seroconversion. In healthcare personnel born after the period when measles incidence significantly decreased, it may be necessary to reassess their immune status for measles if more than 10 years have elapsed since the last vaccination.

Serum Concentration of Antibodies to Mumps, but Not Measles, Rubella, or Varicella, Is Associated with Intake of Dietary Fiber in the NHANES, 1999-2004

Treatment with prebiotics, a type of dietary fiber, was recently shown to increase antibody concentrations following influenza vaccination in a meta-analysis of clinical trials. In observational epidemiologic studies it is not possible to estimate intake of prebiotics, but quantifying intake of dietary fiber is routine. Our objective was to investigate the potential effect of dietary fiber on immunogenicity. We examined serum antibody concentrations (Measles, Mumps, Rubella, and Varicella) in relation to dietary fiber in more than 12,000 subjects in the U.S. National Health and Nutrition Examination Survey (NHANES) for the period 1999-2004. Data from one (1999-2002) or two (2003-2004) dietary recalls were used to calculate fiber intake. For Mumps the adjusted percentage difference in antibody concentration per interquartile range intake in energy-adjusted dietary fiber was 6.34% (95% confidence interval, 3.10, 9.68). Fiber from grain-based foods was more positively associated than fiber from other fiber-containing food groups. The association was slightly larger among subgroups with higher fiber intake, greater interquartile range in fiber intake, and less measurement error. Furthermore, based on the reliability of the diet recalls in 2003-2004, we calculated that the percentage difference per interquartile increment was substantially attenuated by measurement error. Dietary fiber may have a favorable influence on the immunogenicity of some vaccines or natural infections.

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

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

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.

Seropositivity of measles antibodies in the Israeli population prior to the nationwide 2018 - 2019 outbreak

Measles vaccine is administered in Israel as part of the routine childhood immunization program, at ages 1 and 6 years. In this study, we assessed seropositivity of the Israeli population against measles before the onset and propagation of the 2018-2019 measles outbreak. From the Israel Center for Disease Control National Serum Bank, 3,164 samples collected during 2015 were tested for measles antibodies. All the tests were performed using Enzyme-Linked Immunosorbent Assay (ELISA) commercial kit (Enzygnost, Anti-Measles Virus/IgG: Behring, Marburg, Germany). The overall seropositivity rate for measles was 90.7%. The seropositivity rate at 6 months and younger was 48.9%, and decreased to 3.8% among infants aged 6-11 months. Seropositivity increased to 90.7% in the 1-4-year age group, and reached 96.1% for 5-9 year-old children. Our results suggest high immunity in the Israeli population against measles virus, but not high enough to prevent outbreaks because of pockets of specific population groups with low immunization coverage. Infants between ages 6 and 11 months and children younger than 2 years had the lowest seropositivity rates being the age groups with the highest attack rates of measles during the epidemic of 2018. Efforts should be aimed at avoiding any delay in vaccination once a child reaches the age of 1 year and improving immunity levels in children aged 1-4 years.

Seroprevalence of measles antibodies and factors associated with susceptibility: a national survey in Mexico using a plaque reduction neutralization test

Measles continues to be one of the leading causes of child mortality worldwide, even though a highly effective vaccine has existed for more than 40 years. We aimed to describe the seroprevalence of measles antibodies in Mexico in 2012 and the risk factors associated with susceptibility. A total of 7,785 serum samples were analyzed from the National Health and Nutrition Survey in Mexico. This national survey is representative of the general population, including noninstitutionalized adult, adolescent, and child populations. Antibody titers were classified into protective (> 120 mIU/mL) or susceptible (≤ 120 mIU/mL) levels. The weighted seroprevalence and susceptibility of the overall population were 99.37% (95% CI 99.07–99.58) and 0.63% (95% CI 0.42–0.93), respectively. Among 1-to-4-year-old children, 2.18% (95% CI 1.36–3.48) were susceptible to measles. Among adolescents and young adults, the prevalence of susceptibility was as follows: those 15–19 years of age had a prevalence of 0.22% (95% CI 0.09–0.57), and those 30–39 years of age had a prevalence of 1.17% (95% CI 0.47–2.85). Susceptibility was associated with young age, living in Mexico City, living in crowded households and unknown or nonvaccinated status among 1- to 5-year-old children. Although the overall sample population seroprevalence for measles is above 95%, increased susceptibility among younger children signals the importance of the timely administration of the first vaccine dose at 12 months of age. Furthermore, increased susceptibility among specific subgroups indicates the need to reinforce current vaccination policies, including the immunization of unvaccinated or incompletely vaccinated individuals from 10 to 39 years of age.

Surprisingly Low Levels of Measles Immunity in Persons With HIV: A Seroprevalence Survey in a United States HIV Clinic

Background

Measles outbreaks have become increasingly common due to deteriorating vaccination rates, fluctuating herd immunity, and varying antibody decline. Limited knowledge exists regarding prevalence and risk factors associated with measles seronegativity among persons with HIV (PWH).

Methods

This was a cross-sectional study conducted at an academic HIV clinic in Omaha, Nebraska. Participants were screened for the presence of measles IgG antibody. Demographic and clinical information was obtained through electronic medical record review. Simple and multivariable logistic regressions were performed to identify risk factors for measles seronegativity.

Results

Three hundred fifty-one participants were enrolled, with a measles seroprevalence rate of 70.3%. The mean age (range) was 48 (20-74) years, 77% were male, and 53% were Caucasian. The mean CD4 nadir (range) was 334 (1-1675) cells/mm³. At the time of testing, 86% and 87% of the seronegative and seropositive participants had an HIV RNA <50 copies/mL, respectively. Younger age was significantly associated with measles seronegativity (P = .003), as was birth year after 1957 (P = .021). Prior history of measles infection was associated with seropositivity (P = .011). All other risk factors evaluated, including written documentation of adequate vaccination, were not associated with seronegativity.

Conclusions

Our study demonstrates a measles seroprevalence rate that is remarkably lower than previously reported in PWH (92%), and, more importantly, is considerably lower than the rate needed to maintain herd immunity (95%). With higher than expected seronegativity and absence of notable risk factors aside from age, our findings support expanded measles immunity screening for PWH who are at risk of measles exposure.

Australian mumps serosurvey 2012-2013: any cause for concern?

Objectives

To determine population-level immunity to mumps in Australia.

Methods

We tested randomly selected specimens from people aged 1-49 years using the Enzygnost anti-parotitis IgG enzyme immunoassay from an opportunistically collected serum bank in 2012-2013. Weighted estimates of the proportion seropositive and equivocal for mumps-specific IgG antibody were determined by age group and compared with two previous national serosurveys conducted in 2007-2008 and 1997-1998.

Results

Overall, 82.1% (95% CI 80.6-83.5%) of 2,729 specimens were positive or equivocal for mumps-specific IgG antibodies (71.1% positive [95% CI 69.4-72.9%]; 10.9% equivocal [95% CI 9.8-12.2%]). The proportion positive or equivocal was higher in 2012-2013 (82.1%) than in 2007-2008 (75.5%) and 1997-1998 (72.5%), but varied by age. The proportion positive or equivocal in 2012-2013 was above 80% for all age groups older than 1 year except for 30-34 year olds, corresponding to the 1978-1982 birth cohort previously identified as most likely to have missed out on a second MMR vaccine dose.

Conclusion

Seropositivity to mumps in 2012-2013 was well-maintained compared with previous serosurveys. Low mumps notifications over this period in Australia suggest an absence of community-based transmission of mumps infection in the general population, but recent outbreaks among Aboriginal adolescents and young adults in close-contact settings, despite high 2-dose MMR coverage, suggest that seroprotection may be insufficient in other similar settings in Australia.Seropositivity to mumps in 2012-2013 was well-maintained compared with previous serosurveys. Low mumps notifications over this period in Australia suggest an absence of community-based transmission of mumps infection in the general population, but recent outbreaks among Aboriginal adolescents and young adults in close-contact settings, despite high 2-dose MMR coverage, suggest that seroprotection may be insufficient in other similar settings in Australia.

The Clinical Impact and Cost-effectiveness of Measles-Mumps-Rubella Vaccination to Prevent Measles Importations Among International Travelers From the United States

BACKGROUND

Measles importations and the subsequent spread from US travelers returning from abroad are responsible for most measles cases in the United States. Increasing measles-mumps-rubella (MMR) vaccination among departing US travelers could reduce the clinical impact and costs of measles in the United States.

METHODS

We designed a decision tree to evaluate MMR vaccination at a pretravel health encounter (PHE), compared with no encounter. We derived input parameters from Global TravEpiNet data and literature. We quantified Riskexposure to measles while traveling and the average number of US-acquired cases and contacts due to a measles importation. In sensitivity analyses, we examined the impact of destination-specific Riskexposure, including hot spots with active measles outbreaks; the percentage of previously-unvaccinated travelers; and the percentage of travelers returning to US communities with heterogeneous MMR coverage.

RESULTS

The no-encounter strategy projected 22 imported and 66 US-acquired measles cases, costing $14.8M per 10M travelers. The PHE strategy projected 15 imported and 35 US-acquired cases at $190.3M per 10M travelers. PHE was not cost effective for all international travelers (incremental cost-effectiveness ratio [ICER] $4.6M/measles case averted), but offered better value (ICER <$100 000/measles case averted) or was even cost saving for travelers to hot spots, especially if travelers were previously unvaccinated or returning to US communities with heterogeneous MMR coverage.

CONCLUSIONS

PHEs that improve MMR vaccination among US international travelers could reduce measles cases, but are costly. The best value is for travelers with a high likelihood of measles exposure, especially if the travelers are previously unvaccinated or will return to US communities with heterogeneous MMR coverage.

Asthma increases the risk of herpes zoster: a nested case-control study using a national sample cohort

Background

This study aimed to complement previous studies on the risk of herpes zoster in the asthmatic adult population.

Methods

The Korean Health Insurance Review and Assessment Service—National Sample Cohort (HIRA-NSC) from 2002 through 2013 was used. A total of 64,152 participants with herpes zoster were matched for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia with 239,780 participants who were included as a control group. In both the herpes zoster and control groups, previous history of asthma were investigated. The crude and adjusted odds ratios (ORs) and 95% confidence intervals (CI) of asthma for herpes zoster were analyzed using unconditional logistic regression analysis. Subgroup analyses were conducted according to age and sex.

Results

Approximately 16.2% (9728/59,945) and 12.8% (30,752/239,780) of participants in the herpes zoster and control groups, respectively, had a previous history of asthma (P < 0.001). The herpes zoster group demonstrated a 1.32-times higher odds of asthma than the control group (95% CI 1.28–1.35, P < 0.001). The increased odds of asthma in the herpes zoster group persisted in all the age and sex subgroups.

Conclusions

The odds for asthma were higher in the herpes zoster group.

Plasma Donors in the Southwestern United States Positively Contribute to the Diverse Therapeutic Antibody Profile of Immune Globulin Products

Human-plasma-derived immune globulin (IG) is used in augmentation therapy to provide protective levels of antibodies to patients with primary immune deficiency diseases (PIDD) and for prophylaxis against infectious diseases. To maintain the breadth of antibodies necessary for clinical protection, it is important to understand regional patterns of antibody seroprevalence in source plasma from which IG products are manufactured. In this study, source plasma from donation centers in various locations of the Southwestern quarter of the United States was surveyed for antibody titers to hepatitis A virus (HAV), measles virus (MeV), and cytomegalovirus (CMV). A broad range of anti-HAV Ig plasma titers was observed among these centers, with some centers exhibiting 3-5 times the titers of the others. Minor to no differences were observed for levels of anti-MeV and anti-CMV, respectively. Importantly, elevated anti-HAV Ig titers were broadly observed across plasma units obtained from the centers exhibiting high titers, indicative of a potential regional phenomenon among donors as opposed to few donors with singularly high titers. Plasma from these high-titer centers conferred significantly greater neutralization against HAV in vitro. The outcomes of this study give a glimpse of the antibody diversity inherent in human plasma used to manufacture IG products..

Prevalence of Measles Antibodies in São José do Rio Preto, São Paulo, Brazil: A serological survey model

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

Seroepidemiology of Measles, Mumps and Rubella on Bonaire, St. Eustatius and Saba: The First Population-Based Serosurveillance Study in Caribbean Netherlands

The National Immunization Program (NIP) on Bonaire, St. Eustatius and Saba (i.e., Caribbean Netherlands (CN)) includes the measles-mumps-rubella (MMR) vaccine since 1988/89. Seroepidemiological data is an important tool to evaluate the NIP, hence a cross-sectional representative population-based serosurveillance study was conducted for the first time in CN in mid-2017. Participants (n = 1829, aged 0-90 years) donated a blood sample and completed a health-related questionnaire. MMR-specific IgG antibodies were determined using a bead-based multiplex immunoassay and risk factors were analyzed using logistic regression models. Overall seroprevalence was high for measles (94%), but lower for mumps and rubella (both 85%). In NIP eligibles, including women of childbearing age, rubella seroprevalence (88%) exceeded the threshold for protection (85%); however, for measles (89%) this protective level (95%) was not met. MMR seropositivity was lowest in children who became CN resident at 11-17 years of age (especially for measles (72%)), mostly originating from Latin America and other non-Western countries. Interestingly, rubella seroprevalence was lowest in non-NIP eligible adults from Dutch overseas territories and Suriname (75%). Taken together, MMR immunity is generally good in CN, nonetheless some risk groups were identified. Additionally, we found evidence for a unique island epidemiology. In light of recent regional measles outbreaks, disease monitoring remains of utmost importance.

Forecasted Size of Measles Outbreaks Associated With Vaccination Exemptions for Schoolchildren

IMPORTANCE

Vaccine exemptions, which allow unvaccinated children to attend school, have increased by a factor of 28 since 2003 in Texas. Geographic clustering of unvaccinated children facilitates the spread of measles introductions, but the potential size of outbreaks is unclear.

OBJECTIVE

To forecast the range of measles outbreak sizes in each metropolitan area of Texas at 2018 and future reduced school vaccination rates.

DESIGN, SETTING, AND PARTICIPANTS

An agent-based decision analytical model using a synthetic population of Texas, derived from the 2010 US Census, was used to simulate measles transmission in the Texas population. Real schools were represented in the simulations, and the 2018 vaccination rate of each real school was applied to a simulated hypothetical equivalent. Single cases of measles were introduced, daily activities and interactions were modeled for each population member, and the number of infections over the course of 9 months was counted for 1000 simulated runs in each Texas metropolitan area.

INTERVENTIONS

To determine the outcomes of further decreases in vaccination coverage, additional simulations were performed with vaccination rates reduced by 1% to 10% in schools with populations that are currently undervaccinated.

MAIN OUTCOMES AND MEASURES

Expected distributions of outbreak sizes in each metropolitan area of Texas at 2018 and reduced vaccination rates.

RESULTS

At 2018 vaccination rates, the median number of cases in large metropolitan areas was typically small, ranging from 1 to 3 cases, which is consistent with outbreaks in Texas 2006 to 2017. However, the upper limit of the distribution of plausible outbreaks (the 95th percentile, associated with 1 in 20 measles introductions) exceeded 400 cases in both the Austin and Dallas metropolitan areas, similar to the largest US outbreaks since measles was eliminated in 2000. Decreases in vaccination rates in schools with undervaccinated populations in 2018 were associated with exponential increases in the potential size of outbreaks: a 5% decrease in vaccination rate was associated with a 40% to 4000% increase in potential outbreak size, depending on the metropolitan area. A mean (SD) of 64% (11%) of cases occurred in students for whom a vaccine had been refused, but a mean (SD) of 36% (11%) occurred in others (ie, bystanders).

CONCLUSIONS AND RELEVANCE

This study suggests that vaccination rates in some Texas schools are currently low enough to allow large measles outbreaks. Further decreases are associated with dramatic increases in the probability of large outbreaks. Limiting vaccine exemptions could be associated with a decrease in the risk of large measles outbreaks.

Assessment of population immunity to measles in Ontario, Canada: a Canadian Immunization Research Network (CIRN) study

Canada eliminated measles in 1998. We conducted a sero-epidemiology study to estimate population immunity to measles in the province of Ontario, Canada and to identify groups at higher risk of outbreaks. We used a previously developed modified enzyme immunoassay to test 1,199 residual sera from patients aged 1–39 years. We re-tested negative and equivocal sera using a plaque reduction neutralization assay. We interpreted our results in the context of Ontario’s immunization program and vaccine coverage data. Of 1,199 sera, 1035 (86.3%, 95% confidence interval (CI) 84.4, 88.2) were above the measles threshold for protection, 70 (5.8%, 95% CI 4.5, 7.2) were equivocal and 94 (7.8%, 95% CI 6.3, 9.4) were negative. The proportion of positive sera was highest for those 1–5 years, with 180/199 (90.5%, 95% CI 86.4, 94.5) positive sera, and lowest for those age 12–19 years, at 158/199 (79.4%, 95% CI 73.8, 85.0). Adjusted for age, females were more likely than males to have antibody titers above the threshold of protection (odds ratio = 1.60, 95% CI 1.14, 2.24). Most of the study cohort were eligible for two measles vaccine doses, and vaccine uptake in Ontario is >90% for school-aged cohorts. We observed a higher than expected proportion of sera with antibody levels below the threshold of protection, suggesting that immunity in some Ontario age-groups may be waning, despite high vaccine coverage. Alternatively, the traditional measles correlates of protection may not be an appropriate measure of population protection in measles-eliminated settings.

Seroprevalence and durability of rubella virus antibodies in a highly immunized population

BACKGROUND

Although the administration of the measles-mumps-rubella (MMR) vaccine has been widespread in the United States for decades, gaps in vaccine coverage still persist for various reasons. The maintenance of herd immunity against rubella virus (RV) is important to controlling the spread and resurgence of rubella and congenital rubella syndrome.

METHODS

In this study, we sought to assess the seroprevalence of RV-specific antibodies in an adult population from a defined geographic area in Olmsted County, MN, and the surrounding municipalities, with relatively high vaccine coverage and no documented evidence of circulating RV in the past 24 years. Rubella-specific IgG antibodies were measured by ELISA in a large set of serum samples (n = 1393) obtained from the Mayo Clinic Biobank. This cohort was 80.2% female and ranged from 20 to 44 years of age.

RESULTS

In total, 97.8% of subjects were seropositive for rubella-specific IgG antibodies, with a median titer of 40.56 IU/mL, suggesting a high degree of immunization; however, 2.2% of subjects were found to be seronegative. Interestingly, 25.1% of subjects were seropositive but had titers lower than 25 IU/mL, indicating either a population of low responders or individuals that could potentially be at risk of waning immunity. No significant associations or differences were found between RV-specific titers and demographic variables such as age, sex, or body mass index (BMI).

CONCLUSIONS

A high rate of seropositivity for rubella was found among this young adult cohort, but a significant percent of the cohort had lower titers that may indicate poor initial vaccine response and potential risk if their antibody titers decline.

Seroprevalence data at a private teaching hospital in Kenya: An examination of Toxoplasma gondii, cytomegalovirus, rubella, hepatitis A, and Entamoeba histolytica

Background

Relevant seroprevalence data for endemic pathogens in a given region provide insight not only into a population’s susceptibility to acute infection or risk for reactivation disease but also into the potential need for policy initiatives aimed at reducing these risks. Data from sub-Saharan Africa are sparse and since Aga Khan University Hospital Nairobi is an internationally accredited hospital equipped with a laboratory electronic medical record system, analysis of pertinent local seroprevalence data has been made possible.

Methods

We have analyzed serology data from laboratory electronic records at a 300 bed tertiary private teaching hospital in Kenya for the dates, 2008 to 2017 for Toxoplasma gondii, cytomegalovirus, and rubella, which were used primarily for antenatal screening. We also analyzed the data from hepatitis A and amebiasis serologies, which were used primarily for diagnostic purposes.

Results

For T. gondii, cytomegalovirus, and rubella, we used IgG serology to determine seroprevalence, finding rates of 32%, 86%, and 89%, respectively. There was no significant age-related difference in the 20 to 49 year old age range for any of these three pathogens. Of the Hepatitis A IgM tests that were ordered, 33% were positive with a peak positive rate of 70% in the five to nine year old age range. The seroprevalence of amebiasis was 4% and all cases of seropositivity were accompanied by compatible clinical illness (hepatic abscess).

Conclusions

These data provide insight into seroprevalence rates of selected pathogens that can be used to guide screening and diagnostic laboratory testing as well as private and public immunization practices.

Varicella in the prison setting: A report of three outbreaks in Rhode Island and a review of the literature

BACKGROUND

The prison setting carries unique risks for varicella outbreaks and the disease in adults, particularly those who are immunocompromised, can be life-threatening. In 2016-17, there were three outbreaks of varicella at three different correctional facilities in Rhode Island. The Centers for Disease Control and Prevention (CDC) recommend post-exposure vaccination within three to five days for affected populations however the Federal Bureau of Prisons (BOP) notes the logistical challenges of vaccinating exposed incarcerated individuals.

MATERIAL AND METHODS

A descriptive analysis was performed for each outbreak along with an overview of the response. Varicella serologies were obtained from the exposed population at each facility and the results compiled for comparative analysis. A literature review was then performed to identify and analyze other reported varicella outbreaks in incarcerated populations.

RESULTS

In each outbreak, the sentinel event was an inmate with herpes zoster. In prison A, there were 432 inmates exposed to the virus leading to 5 cases of varicella, while the outbreak in Prison B exposed 46 inmates and led to 3 cases. In Prison C, there was one case of primary varicella and 97 inmates were exposed.

DISCUSSION

It is remarkable that there were 3 unrelated outbreaks in a short time and, although corroborating data would be necessary to establish a trend, it may signal an increased risk of varicella transmission within this population. Correctional facilities should remain vigilant and have plans for managing the disease including isolation protocols, serology testing and post-exposure vaccination when indicated. While the BOP does not provide clear recommendations on the use of post-exposure prophylaxis during an outbreak response in this population, the experience in Rhode Island and the review of the literate demonstrate steps that can be taken to facilitate a response including post-exposure vaccination in line with CDC recommendations.

The declining antibody level of measles virus in China population, 2009-2015

Background

To eliminate measles, the coverage of more than 90% vaccine is required in China. Nonetheless, the measles incidence still reached to 3.88 per 100,000 in 2014, which is far more than the target of 1 per 1,000,000. Moreover, there is little national surveillance to measles antibody level indicating herd immunity status in China.

Methods

We detected the level of antibody to measles using commercially available indirect enzyme-linked immunosorbent IgG assays, and calculated the protection rate of population (PRP) to measles virus infection among health peoples in China.

Results

During the years 2009–2015, among the Chinese population aged 0–56, PRP was 94.7, 91.6, 91.6, 84.2, 82.1, 81.0, 75.4%, respectively. Among all age bands, the PRP is lowest among children less than 12-month-age, followed by people over 15 years old.

Conclusion

Measles antibody level among healthy population has been declined since 2012, supplemented measles vaccination activity may be necessary to eliminate measles in China.

Varicella Vaccination Among US Adolescents: Coverage and Missed Opportunities, 2007-2014

CONTEXT

Since 2007, 2 doses of varicella vaccine have been routinely recommended, with a catch-up second dose recommended for those who received only 1 prior dose.

OBJECTIVE

To examine varicella vaccination coverage with 2 or more doses and the proportions of adolescents with evidence of immunity to varicella (≥2 doses of vaccine or varicella history) during 2007-2014. To assess timing of second-dose receipt, factors associated with 2 or more vaccine doses, and missed second-dose opportunities during 2014.

DESIGN, SETTING, AND PARTICIPANTS

We used data from the 2007-2014 National Immunization Survey-Teen (NIS-Teen), which collects information on adolescents aged 13 to 17 years in the United States.

RESULTS

From 2007 to 2014, varicella vaccination coverage with 2 or more doses increased from 8.3% to 66.9% in 13- to 15-year-olds and from 3.6% to 56.7% in 16- to 17-year-olds. The proportions with evidence of immunity also increased from 68.0% to 84.1% (13- to 15-year-olds) and 78.6% to 83.4% (16- to 17-year-olds). In 2014, 13.4% of 13- to 15-year-olds and 3.2% of 16- to 17-year-olds had received their second dose at 4 to 6 years of age. Factors most significantly associated with lower coverage with 2 or more doses were not having an 11- to 12-year well-child visit, not receiving an adolescent vaccine, and residence in a state with no 2-dose immunization school entry requirement. Seventy-seven percent of 1-dose vaccinated adolescents had 1 or more missed opportunities to receive their second dose; if were they not missed, 2-dose coverage would have increased from 79.5% to 94.8%.

CONCLUSIONS

Levels of varicella vaccination coverage with 2 or more doses and the proportion of adolescents with evidence of immunity increased from 2007 to 2014, though 16% lacked evidence of immunity in 2014. Although catch-up campaigns have succeeded, missed vaccination opportunities persist.

Prevalence of Inadequate Immunity to Measles, Mumps, Rubella, and Varicella in MLB and NBA Athletes

BACKGROUND

Multiple outbreaks of vaccine-preventable viral diseases have occurred in professional sports in recent years. Currently, there is no established protocol for vaccination or immunity screening for professional athletes.

HYPOTHESIS

There are significant differences in the prevalence of inadequate immunity dependent on age, sport, country of birth, and participation in collegiate sports.

STUDY DESIGN

Cross-sectional cohort study.

LEVEL OF EVIDENCE

Level 4.

METHODS

A sample of Major League Baseball (MLB) and National Basketball Association (NBA) players were screened for serologic evidence of immunity to measles, mumps, rubella, and varicella prior to the 2015 and 2016 seasons. The results were designated as adequate (immune) or inadequate (equivocal or nonimmune) based on laboratory criteria. Comparison with an age-matched control group was performed using data from the National Health and Nutrition Examination Survey (NHANES).

RESULTS

A total of 98 athletes (62 MLB, 36 NBA) were screened. The prevalence of inadequate immunity for any virus was 35.5% in MLB players and 33.3% in NBA players. There was a significantly greater risk of inadequate immunity to rubella (risk ratio, 6.38; P < 0.01) and varicella (risk ratio, 4.21; P < 0.01) in athletes compared with the age-matched NHANES population. Our analysis did not reveal differences in rates of immunity based on sport, country of birth (US born vs international), or participation in college athletics. There was a lower rate of inadequate immunity to varicella with increasing age (odds ratio, 0.72; P = 0.05).

CONCLUSION

One-third of athletes studied had inadequate immunity to 1 of the 4 viruses tested. Younger players had a significantly greater risk of inadequate immunity to varicella. Birth outside the US and lack of participation in college athletics were not found to influence immunity rates.

CLINICAL RELEVANCE

These results can inform the development of future screening programs to prevent outbreaks of viral infections in professional athletes.

Carrier Cells for Delivery of Oncolytic Measles Virus into Tumors: Determinants of Efficient Loading

Oncolytic measles virus (OMV) is a promising antitumor agent. However, the presence of anti-measles neutralizing antibodies (NAbs) against the hemagglutinin (H) protein of OMV is a major barrier to the therapeutic application of OMV in clinical practice. In order to overcome this challenge, specific types of cells have been used as carriers for OMV. Differential loading strategies appear to result in different therapeutic outcomes; despite this, only few studies have reported practical ex vivo loading strategies required for effective treatment. To this end, we systematically evaluated the antitumor efficacy of OMV using different loading strategies; this involved varying the in vitro loading duration and loading dose of OMV. We found that improved oncolysis of carrier cells was achieved by a prolonged loading duration in the absence of NAbs. However, the enhanced oncolytic effect was abrogated in the presence of NAbs. Further, we found that the expression of H protein on the surface of carrier cells was predominantly determined by the loading duration rather than the loading dose. Finally, we showed that NAbs blocked viral transfer by targeting H protein prior to the occurrence of cell-to-cell interactions. Our results provide comprehensive information on the determinants of an effective loading strategy for carrier cell-based virotherapy; these results may be useful for guiding the application of OMV as an antitumor agent in clinical practice.

Declining measles antibodies in the era of elimination: Australia's experience

BACKGROUND

Australia is one of only a few countries with a long-standing and consistent serosurveillance program. We conducted a national serosurvey in 2012-2013 to estimate population seroprevalence of measles-specific IgG and the effective reproduction number, R, and compare the results with the three previous serosurveys (1996-1999, 2002 and 2007) to examine trends following a decade of sustained measles control.

METHODS

2729 residual sera from 1 to 49 year olds were tested using the Enzygnost anti-measles IgG enzyme immunoassay (EIA). All sera in the equivocal range by EIA on re-testing and a random sample of low positive and negative sera were later tested by a microneutralisation assay. R was calculated from weighted estimates of the proportion seronegative by age using a previously developed contact matrix.

RESULTS

In the 2012-13 serosurvey, anti-measles IgG seropositivity for 1-49 year olds was 80.8% (95% CI: 79.4-82.3%) and 8.9% (95% CI: 7.8-10.0%) had equivocal antibody levels. The increasing proportion of seronegative and equivocal individuals in age groups 10-39 years continued a trend seen in previous serosurveys. There was also an increase in equivocal results among 2-4 and 5-9 year old children, >90% of whom were recently vaccinated. R increased from 0.57 in 1999 to above the epidemic threshold of 1 in 2012-13 (R = 1.7). All 20 EIA negative sera, 238/241 (98.8%) equivocal sera, and 89/92 (96.7%) low positive sera had a titre <10 (negative) in the measles microneutralisation assay.

CONCLUSIONS

A number of countries with sustained measles control have now demonstrated that measles-specific IgG antibodies decline with time since vaccination. As there is good epidemiologic evidence of population-level protection, the implications of declining measles-specific IgG antibody levels for maintaining measles elimination are unclear. Novel studies to determine correlates of protection against measles transmission and disease in the post-elimination era are needed to help answer this question.

Association between seroprevalence of measles and various social determinants in the year following a measles outbreak in Turkey

OBJECTIVES

Despite an ongoing measles elimination programme, a measles outbreak occurred in 2013 in Turkey. Population-based seroprevalence studies are needed to determine seronegativity and explore the reasons for this outbreak. This study aimed to explore the seroprevalence of measles and its association with various social determinants in a provincial population in Turkey in the year following a measles outbreak.

STUDY DESIGN

Cross-sectional study.

METHODS

This study was conducted in Manisa Province in 2014 in a sample of 1740 people aged >2 years. The dependent variable was the seroprevalence of measles. Independent variables were sex, age, migration, household size, household density, income, education level, existence of chronic disease and occupational class. Blood samples were collected from participants at family health centres. The presence of specific measles antibodies in serum samples was determined using an anti-measles virus IgG enzyme-linked immunosorbent assay test. Chi-squared test and logistic regression analysis were performed.

RESULTS

Overall, data from 1250 people were analysed. The seroprevalence of measles in the whole study population was 82.2% (95% confidence interval 80.0-84.2). Seroprevalence was 55.4% among subjects aged 2-9 years, 48.7% among subjects aged 10-19 years, 74.1% among subjects aged 20-29 years and 93.6% among subjects aged 30-39 years (P < 0.01). Seroprevalence in subjects aged >40 years was >95%. The lowest seroprevalence was found in primary school children (40.2%), followed by those below the age for primary education (69.8%) and secondary school graduates (75.1%). The prevalence of measles seronegativity was not associated with any of the social determinants when adjusted for age.

CONCLUSIONS

The seroprevalence of measles was lower than expected in the study population and was particularly low in subjects aged <30 years of age despite previous vaccination. Seroprevalence was not associated with social determinants of health that confirmed either an even distribution of virus exposure or fair access to vaccination services. However, the current seroprevalence cannot be sufficiently effective to reach the measles elimination targets, suggesting that it may be necessary to re-evaluate the need for an extra dose of measles vaccine.

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.

Varicella immunization requirements for US colleges: 2014-2015 academic year

OBJECTIVE

To obtain information on varicella prematriculation requirements in US colleges for undergraduate students during the 2014-2015 academic year.

PARTICIPANTS

Health care professionals and member schools of the American College Health Association (ACHA).

METHODS

An electronic survey was sent to ACHA members regarding school characteristics and whether schools had policies in place requiring that students show proof of 2 doses of varicella vaccination for school attendance.

RESULTS

Only 27% (101/370) of schools had a varicella prematriculation requirement for undergraduate students. Only 68% of schools always enforced this requirement. Private schools, 4-year schools, northeastern schools, those with <5,000 students, and schools located in a state with a 2-dose varicella vaccine mandate were significantly more likely to have a varicella prematriculation requirement.

CONCLUSIONS

A small proportion of US colleges have a varicella prematriculation requirement for varicella immunity. College vaccination requirements are an important tool for controlling varicella in these settings.

Systematic Review of Measles and Rubella Serology Studies

Serological tests provide information about individual immunity from historical infection or immunization. Cross-sectional serological studies provide data about the age- and sex-specific immunity levels for individuals in the studied population, and these data can provide a point of comparison for the results of transmission models. In the context of developing an integrated model for measles and rubella transmission, we reviewed the existing measles and rubella literature to identify the results of national serological studies that provided cross-sectional estimates of population immunity at the time of data collection. We systematically searched PubMed, the Science Citation Index, and references we identified from relevant articles published in English. We extracted serological data for comparison to transmission model outputs. For rubella, serological studies of women of child-bearing age provide information about the potential risks of infants born with congenital rubella syndrome. Serological studies also document the loss of maternal antibodies, which occurs at different rates for the different viruses and according to the nature of the induced immunity (i.e., infection or vaccine). The serological evidence remains limited for some areas, with studies from developed countries representing a disproportionate part of the evidence. The collection and review of serological evidence can help program managers identify immunity gaps in the population, which may help them better understand the characteristics of individuals within their populations who may participate in transmission and manage risks.

Measles susceptibility in young Thai men suggests need for young adult measles vaccination: a cross sectional study

Background

Measles remains a major public health concern in Thailand despite the introduction of vaccination since 1984. Similar to other countries, Thailand has experienced numerous measles outbreaks including adult communities such as university student dormitories, prisons, refugee camps, and military recruit camps. These outbreaks raise questions on the seroprotective antibody level in Thai adults.

Methods

To better understand measles susceptibility in young Thai adults, a retrospective measles seroprevalence study on repository serum specimens obtained with informed consent from young Thai men entering the Royal Thai Army (RTA) during 2007–2008 was conducted. A total of 7760 stratified randomized samples were chosen by residence province. Measles IgG titer was measured using a commercial IgG quantitative ELISA kit following the manufacturer’s instructions. An antibody level ≥ 250 International Units per Liter (IU/L) was interpreted as seropositive.

Results

The overall measles seroprevalence was 78.5 % (95 % Confidence Interval: 77.6–79.4 %) with geometric mean titer of 738 IU/L (95 % Confidence Interval: 716–760 IU/L). The measles seroprevalence by province ranged from 59.6 % to 93.1 %. A trend of decreasing seroprevalence in the younger cohorts despite increasing immunization coverage was found. Lower seroprevalence than vaccination coverage was observed in the youngest age group.

Conclusions

To achieve long term measles control and elimination, an integrated two doses vaccination strategy has been implemented in children in Thailand. This nationwide measles seroprevalence study in young adult RTA recruits found a measles seroprevalence lower than WHO’s recommendation for measles outbreak prevention and elimination. These results raise concerns for measles control in Thailand. Supplementary immunization in young adults is essential especially in high-risk and densely populated communities to establish herd immunity for outbreak prevention and elimination.

Association Between Prenatal Exposure to Maternal Infection and Offspring Mood Disorders: A Review of the Literature

The purpose of this article is to provide a systematic review of studies that have examined the association between prenatal exposure to maternal infection and development of mood disorders across the life course. Drawing from both human- and animal-based studies, we give an overview of hypothesized biological mechanisms by which exposure to maternal infection during critical periods of gestation may contribute to fetal programming of mood disorders in offspring. We discuss studies examining the association between prenatal exposure to maternal infection with pathogens including influenza as well as other respiratory viruses, herpesviruses, hepatitis viruses, and Toxoplasma gondii and mood disorders in human populations. Moreover, we outline strengths and limitations of the current body of evidence and make recommendations for future research. We also discuss findings in the context of well-documented gender and socioeconomic disparities in the prevalence and severity of mood disorders, particularly major depression, and the role that early exposure to infection may play in explaining the perpetuation of such disparities across generations. Overall, this review of the current knowledge on this topic has important implications for determining future research directions, designing interventions as well as prenatal care guidelines targeted at prevention or treatment of infection during pregnancy, and clinical practice for the identification of individuals that may be at increased risk for mood disorders beginning early in life. Importantly, such efforts may not only lower the overall burden of mood disorders but also serve to address social disparities in these adverse mental health conditions in the U.S.

Clinical and economic impact of various strategies for varicella immunity screening and vaccination of health care personnel

BACKGROUND

Exposure to patients with varicella or herpes zoster causes considerable disruption to a health care facility's operations and has a significant health and economic impact. However, practices related to screening for immunity and immunization of health care personnel (HCP) for varicella vary widely.

METHODS

A decision tree model was built to evaluate the cost-effectiveness of 8 different strategies of screening and vaccinating HCP for varicella. The outcomes are presented as probability of acquiring varicella, economic impact of varicella per employee per year, and cost to prevent additional cases of varicella. Monte Carlo simulations and 1-way sensitivity analyses were performed to address the uncertainties inherent to the model. Alternative epidemiologic and technologic scenarios were also analyzed.

RESULTS

Performing a clinical screening followed by serologic testing of HCP with negative history diminished the cost impact of varicella by >99% compared with not having a program. Vaccinating HCP with negative screen cost approximately $50,000 per case of varicella prevented at the current level of U.S. population immunity, but was projected to be cost-saving at 92% or lower immunity prevalence. Improving vaccine acceptance rates and using highly sensitive assays also optimize cost-effectiveness.

CONCLUSION

Strategies relying on screening and vaccinating HCP for varicella on employment were shown to be cost-effective for health care facilities and are consistent with current national guidelines for varicella prevention.