Mounting a good offense against measles

A neutralizing antibody prevents postfusion transition of measles virus fusion protein

Measles virus (MeV) presents a public health threat that is escalating as vaccine coverage in the general population declines and as populations of immunocompromised individuals, who cannot be vaccinated, increase. There are no approved therapeutics for MeV. Neutralizing antibodies targeting viral fusion are one potential therapeutic approach but have not yet been structurally characterized or advanced to clinical use. We present cryo-electron microscopy (cryo-EM) structures of prefusion F alone [2.1-angstrom (Å) resolution], F complexed with a fusion-inhibitory peptide (2.3-Å resolution), F complexed with the neutralizing and protective monoclonal antibody (mAb) 77 (2.6-Å resolution), and an additional structure of postfusion F (2.7-Å resolution). In vitro assays and examination of additional EM classes show that mAb 77 binds prefusion F, arrests F in an intermediate state, and prevents transition to the postfusion conformation. These structures shed light on antibody-mediated neutralization that involves arrest of fusion proteins in an intermediate state.

Epidemiology of measles in Angola: Results from routine surveillance from 2015 to 2021

Background

Measles, an acute infectious disease of extremely contagious viral aetiology, has been eliminated in some parts of the world. To the best of the authors' knowledge, this is the first study on the epidemiological pattern of the measles virus in Angola, and it was carried out through a review of 7 years of observational retrospective data from the national measles laboratory surveillance programme.

Methods

A retrospective study using national databases on the laboratory surveillance of measles was performed. Patients of all ages with suspected measles from all provinces of Angola were included. Serum samples were used to detect IgM-type measles-virus-specific antibodies by enzyme-linked immunosorbent assay.

Findings

In total, 3690 suspected measles samples were sent to the Instituto Nacional de Investigação em Saúde. There were 962 (26.1%) laboratory-confirmed cases, and the most affected age group was children aged 1-4 years. The highest incidence rate per 100,000 population was found in Benguela (17.9%), followed by Huambo (16.7%) and Cuanza Sul (13.6%). Of the study years, the incidence rate per 1,000,000 population was highest in 2020 (11.9%). The most common complication was diarrhoea (n=406, 42.2%). Of the confirmed cases, 209 (21.7%) were vaccinated, 633 (65.8%) were unvaccinated, and 120 (12.5%) had unknown vaccination status. For all study years, vaccination coverage was <70%.

Interpretation

Measles continues to be a serious problem in Angola, and more efforts are needed to increase measles surveillance and achieve a high percentage of vaccination coverage.

Attitudes and Beliefs around the Value of Vaccination in the United States

Despite the benefits of immunization, differences in attitudes persist toward vaccines. We captured individuals’ perceptions of vaccines and vaccination across the United States (US) to inform vaccine-related policy development. A survey was completed by 5000 respondents from 10 states. Respondents were screened for inclusion, which included individuals ≥ 18 years of age that had received a vaccine or were unvaccinated but indicated a favorable or neutral attitude towards vaccinations. Participants were excluded if they indicated they did not support the idea of vaccinations. Questions explored perceptions of vaccines for all age groups. Among unvaccinated individuals, the most common concerns were about safety (38%). Most respondents (95%) highlighted the importance of state immunization programs for disease prevention. Access to health and immunization records and immunization information systems were important to 96% and 88% of respondents, respectively, for future health planning. Doctors and healthcare professionals (HCPs) were considered trusted sources for vaccine information (95%). Overall, respondents recognized the importance of vaccination, but documented concerns among the unvaccinated indicated a need for greater promotion regarding vaccine safety. Doctors and HCPs, as trusted information sources, should continue to and increasingly advocate for the importance of immunization to increase vaccine uptake.

The Clinical and Economic Impact of Measles-Mumps-Rubella Vaccinations to Prevent Measles Importations From US Pediatric Travelers Returning From Abroad

BACKGROUND

Pediatric international travelers account for nearly half of measles importations in the United States. Over one third of pediatric international travelers depart the United States without the recommended measles-mumps-rubella (MMR) vaccinations: 2 doses for travelers ≥12 months and 1 dose for travelers 6 to <12 months.

METHODS

We developed a model to compare 2 strategies among a simulated cohort of international travelers (6 months to <6 years): (1) No pretravel health encounter (PHE): travelers depart with baseline MMR vaccination status; (2) PHE: MMR-eligible travelers are offered vaccination. All pediatric travelers experience a destination-specific risk of measles exposure (mean, 30 exposures/million travelers). If exposed to measles, travelers' age and MMR vaccination status determine the risk of infection (range, 3%-90%). We included costs of medical care, contact tracing, and lost wages from the societal perspective. We varied inputs in sensitivity analyses. Model outcomes included projected measles cases, costs, and incremental cost-effectiveness ratios ($/quality-adjusted life year [QALY], cost-effectiveness threshold ≤$100 000/QALY).

RESULTS

Compared with no PHE, PHE would avert 57 measles cases at $9.2 million/QALY among infant travelers and 7 measles cases at $15.0 million/QALY among preschool-aged travelers. Clinical benefits of PHE would be greatest for infants but cost-effective only for travelers to destinations with higher risk for measles exposure (ie, ≥160 exposures/million travelers) or if more US-acquired cases resulted from an infected traveler, such as in communities with limited MMR coverage.

CONCLUSIONS

Pretravel MMR vaccination provides the greatest clinical benefit for infant travelers and can be cost-effective before travel to destinations with high risk for measles exposure or from communities with low MMR vaccination coverage.

Transmission-Blocking Preventive Measures for Infectious Diseases: Altruism, Solidarity, and the Common Good

Aiming to prevent the spread of contagious diseases has long been a central tenet of public health. In the present time, divisive political responses to mask wearing to prevent SARS-CoV-2 transmission have competed with sound public health advice for public attention. Here, we draw parallels in terms of individualism versus societal solidarity between the slow and ponderous development of transmission-blocking vaccines for malaria and advocacy for mask wearing to prevent COVID-19.

Progress towards the development of a P. vivax vaccine

INTRODUCTION

Plasmodium vivax causes significant public health problems in endemic regions. A vaccine to prevent disease is critical, considering the rapid spread of drug-resistant parasite strains, and the development of hypnozoites in the liver with potential for relapse. A minimally effective vaccine should prevent disease and transmission while an ideal vaccine provides sterile immunity.

AREAS COVERED

Despite decades of research, the complex life cycle, technical challenges and a lack of funding have hampered progress of P. vivax vaccine development. Here, we review the progress of potential P. vivax vaccine candidates from different stages of the parasite life cycle. We also highlight the challenges and important strategies for rational vaccine design. These factors can significantly increase immune effector mechanisms and improve the protective efficacy of these candidates in clinical trials to generate sustained protection over longer periods of time.

EXPERT OPINION

A vaccine that presents functionally-conserved epitopes from multiple antigens from various stages of the parasite life cycle is key to induce broadly neutralizing strain-transcending protective immunity to effectively disrupt parasite development and transmission.

Precision Surveillance for Viral Respiratory Pathogens: Virome Capture Sequencing for the Detection and Genomic Characterization of Severe Acute Respiratory Infection in Uganda

Background

Precision public health is a novel set of methods to target disease prevention and mitigation interventions to high-risk subpopulations. We applied a precision public health strategy to syndromic surveillance for severe acute respiratory infection (SARI) in Uganda by combining spatiotemporal analytics with genomic sequencing to detect and characterize viral respiratory pathogens with epidemic potential.

Methods

Using a national surveillance network we identified patients with unexplained, influenza-negative SARI from 2010 to 2015. Spatiotemporal analyses were performed retrospectively to identify clusters of unexplained SARI. Within clusters, respiratory viruses were detected and characterized in naso- and oropharyngeal swab samples using a novel oligonucleotide probe capture (VirCapSeq-VERT) and high-throughput sequencing platform. Linkage to conventional epidemiologic strategies further characterized transmission dynamics of identified pathogens.

Results

Among 2901 unexplained SARI cases, 9 clusters were detected, accounting for 301 (10.4%) cases. Clusters were more likely to occur in urban areas and during biannual rainy seasons. Within detected clusters, we identified an unrecognized outbreak of measles-associated SARI; sequence analysis implicated cocirculation of endemic genotype B3 and genotype D4 likely imported from England. We also detected a likely nosocomial SARI cluster associated with a novel picobirnavirus most closely related to swine and dromedary viruses.

Conclusions

Using a precision approach to public health surveillance, we detected and characterized the genomics of vaccine-preventable and zoonotic respiratory viruses associated with clusters of severe respiratory infections in Uganda. Future studies are needed to assess the feasibility, scalability, and impact of applying similar approaches during real-time public health surveillance in low-income settings.

Acceptability of a herd immunity-focused, transmission-blocking malaria vaccine in malaria-endemic communities in the Peruvian Amazon: an exploratory study

BACKGROUND

A transmission-blocking vaccine (TBV) to prevent malaria-infected humans from infecting mosquitoes has been increasingly considered as a tool for malaria control and elimination. This study tested the hypothesis that a malaria TBV would be acceptable among residents of a malaria-hypoendemic region.

METHODS

The study was carried out in six Spanish-speaking rural villages in the Department of Loreto in the Peruvian Amazon. These villages comprise a cohort of 430 households associated with the Peru-Brazil International Centre for Excellence in Malaria Research. Individuals from one-third (143) of enrolled households in an ongoing longitudinal, prospective cohort study in 6 communities in Loreto, Peru, were randomly selected to participate by answering a pre-validated questionnaire.

RESULTS

All 143 participants expressed desire for a malaria vaccine in general; only 1 (0.7%) expressed unwillingness to receive a transmission-blocking malaria vaccine. Injection was considered most acceptable for adults (97.2%); for children drops in the mouth were preferred (96.8%). Acceptability waned marginally with the prospect of multiple injections (83.8%) and different projected efficacies at 70 and 50% (90.1 and 71.8%, respectively). Respondents demonstrated clear understanding that the vaccine was for community, rather than personal, protection against malaria infection.

DISCUSSION

In this setting of the Peruvian Amazon, a transmission-blocking malaria vaccine was found to be almost universally acceptable. This study is the first to report that residents of a malaria-endemic region have been queried regarding a malaria vaccine strategy that policy-makers in the industrialized world often dismiss as altruistic.

Understanding modern-day vaccines: what you need to know

Vaccines are considered to be one of the greatest public health achievements of the last century. Depending on the biology of the infection, the disease to be prevented, and the targeted population, a vaccine may require the induction of different adaptive immune mechanisms to be effective. Understanding the basic concepts of different vaccines is therefore crucial to understand their mode of action, benefits, risks, and their potential real-life impact on protection. This review aims to provide healthcare professionals with background information about the main vaccine designs and concepts of protection in a simplified way to improve their knowledge and understanding, and increase their confidence in the science of vaccination ( Supplementary Material ). KEY MESSAGE Different vaccine designs, each with different advantages and limitations, can be applied for protection against a particular disease. Vaccines may contain live-attenuated pathogens, inactivated pathogens, or only parts of pathogens and may also contain adjuvants to stimulate the immune responses. This review explains the mode of action, benefits, risks and real-life impact of vaccines by highlighting key vaccine concepts. An improved knowledge and understanding of the main vaccine designs and concepts of protection will help support the appropriate use and expectations of vaccines, increase confidence in the science of vaccination, and help reduce vaccine hesitancy.

Does disease cause vaccination? Disease outbreaks and vaccination response

Parental fear of vaccines has limited vaccination rates in the United States. I test whether disease outbreaks increase vaccination using a new dataset of county-level disease and vaccination data. I find that pertussis (whooping cough) outbreaks in a county decrease the share of unvaccinated children entering kindergarten. These responses do not reflect changes in the future disease risk. I argue that these facts are best fit by a model in which individuals are both myopic and irrational. This suggests that better promotion of information about outbreaks could enhance the response.

Risk analysis for the reintroduction and transmission of measles in the post-elimination period in the Americas

Objective.

To propose and test a model for analyzing municipalities’ level of risk of reintroduction and transmission of the measles virus in the post-elimination period in the Americas.

Methods.

An ecological-analytical study was conducted using data on the measles epidemic that occurred in 2013–2015 in northeastern Brazil. The variables for analysis were selected after an extensive review of scientific literature on the risk of importation of measles cases. A univariate analysis considering the presence or absence of confirmed cases of measles in 184 municipalities in the state of Ceará, Brazil, was carried out to evaluate the association between the dependent variable and 23 independent variables, grouped into four categories: 1) characteristics of the municipalities; 2) quality indicators for immunization programs and epidemiological surveillance; 3) organizational structure for the public health response; and 4) selected impact indicators. A P value < 0.05 was considered significant. All variables with P < 0.200 were analyzed using multivariate logistic regression. Based on the results, the municipalities were categorized by four levels of risk (“low,” “medium,” “high,” and “very high”).

Results.

The model sensitivity was 95% for concordance between municipalities classified as “high risk” and “very high risk” and those that had an epidemic between 2013 and 2015 in Ceará. Of the 38 municipalities that had an epidemic, 76% (29/38) were classified as “high risk” and “very high risk”; 146 municipalities did not report cases (P < 0.0002).

Conclusions.

Given the imminent risk of reintroduction of measles circulation in the post-elimination period in the Americas, this model may be useful in identifying areas at greater risk for reintroduction and continued transmission of measles. Knowledge of vulnerable areas could trigger appropriate surveillance and monitoring to prevent sustained transmission.

County-level assessment of United States kindergarten vaccination rates for measles mumps rubella (MMR) for the 2014-2015 school year

United States kindergarten measles-mumps-rubella (MMR) vaccination rates are typically reported at the state level by the Centers for Disease Control and Prevention (CDC). The lack of local MMR data prevents identification of areas with low vaccination rates that would be vulnerable to the spread of disease. We collected county-level vaccination rates for the 2014-2015 school year with the objective of identifying these regions. We requested county-level kindergarten vaccination data from state health departments, and mapped these data to visualize geographic patterns in achievement of the 95% MMR vaccination target. We aggregated the county-level data to the state level for comparison against CDC state estimates. We also analyzed the relationship of MMR vaccination level with county-level and state-level poverty (using U.S. census data), using both a national mixed model with state as a random effect, and individual linear regression models by state. We received county vaccination data from 43 states. The median kindergarten MMR vaccination rate was 96.0% (IQR 89-98) across all counties, however, we estimated that 48.4% of the represented counties had vaccination rates below 95%. Our state estimates closely reflected CDC values. Nationally, every 10% increase in under-18 county poverty was associated with a 0.24% increase in MMR vaccination rates (95% CI: -0.07%; 0.54%), but the direction of this relationship varied by state. We found that county data can reveal vaccination trends that are unobservable from state-level data, but we also discovered that the current availability of county-level data is inadequate. Our findings can be used by state health departments to identify target areas for vaccination programs.

Measles Outbreak in a Child Care Center, Cook County, Illinois, 2015

BACKGROUND

During January-February 2015, Cook County Department of Public Health led an investigation of a measles outbreak predominantly affecting infants at a child care center who were too young for routine immunization with measles-mumps-rubella (MMR) vaccine.

METHODS

Measles cases and contacts were investigated by Illinois public health officials. Cases were isolated for 4 days after rash onset. Exposed healthcare workers and child care center staff were required to provide documentation of receipt of 2 doses of MMR vaccine or laboratory evidence of immunity to return to work. Susceptible contacts were actively monitored for 21 days after exposure and provided postexposure prophylaxis (PEP) if certain criteria were met.

RESULTS

Fifteen confirmed measles cases were identified; 12 (80%) occurred in infants who were attendees of a child care center. Clinical misdiagnosis of 1 case allowed for continued transmission within the center. Twelve (86%) of 14 exposed infants at the child care center were diagnosed with measles; no other attendees or staff were infected. Five cases visited outpatient pediatric clinics during their infectious period, exposing 33 infants. Six exposed child care center staff and 3 healthcare workers did not have documentation of immunity available and were excluded from work until this was obtained. No healthcare-associated transmission was identified. Ninety-one contacts were actively monitored and 20 received PEP.

CONCLUSIONS

This outbreak underscores the vulnerability of infants to measles, the need for early consideration of measles in susceptible patients presenting with a febrile rash illness, and the importance of immunity among individuals working closely with infants.

Geospatial characteristics of measles transmission in China during 2005-2014

Measles is a highly contagious and severe disease. Despite mass vaccination, it remains a leading cause of death in children in developing regions, killing 114,900 globally in 2014. In 2006, China committed to eliminating measles by 2012; to this end, the country enhanced its mandatory vaccination programs and achieved vaccination rates reported above 95% by 2008. However, in spite of these efforts, during the last 3 years (2013-2015) China documented 27,695, 52,656, and 42,874 confirmed measles cases. How measles manages to spread in China-the world's largest population-in the mass vaccination era remains poorly understood. To address this conundrum and provide insights for future public health efforts, we analyze the geospatial pattern of measles transmission across China during 2005-2014. We map measles incidence and incidence rates for each of the 344 cities in mainland China, identify the key socioeconomic and demographic features associated with high disease burden, and identify transmission clusters based on the synchrony of outbreak cycles. Using hierarchical cluster analysis, we identify 21 epidemic clusters, of which 12 were cross-regional. The cross-regional clusters included more underdeveloped cities with large numbers of emigrants than would be expected by chance (p = 0.011; bootstrap sampling), indicating that cities in these clusters were likely linked by internal worker migration in response to uneven economic development. In contrast, cities in regional clusters were more likely to have high rates of minorities and high natural growth rates than would be expected by chance (p = 0.074; bootstrap sampling). Our findings suggest that multiple highly connected foci of measles transmission coexist in China and that migrant workers likely facilitate the transmission of measles across regions. This complex connection renders eradication of measles challenging in China despite its high overall vaccination coverage. Future immunization programs should therefore target these transmission foci simultaneously.

Measles epidemic in Brazil in the post-elimination period: Coordinated response and containment strategies

The measles virus circulation was halted in Brazil in 2001 and the country has a routine vaccination coverage against measles, mumps and rubella higher than 95%. In Ceará, the last confirmed case was in 1999. This article describes the strategies adopted and the effectiveness of surveillance and control measures implemented during a measles epidemic in the post-elimination period. The epidemic started in December 2013 and lasted 20 months, reaching 38 cities and 1,052 confirmed cases. The D8 genotype was identified. More than 50,000 samples were tested for measles and 86.4% of the confirmed cases had a laboratory diagnosis. The beginning of an campaign vaccination was delayed in part by the availability of vaccine. The classic control measures were not enough to control the epidemic. The creation of a committee of experts, the agreement signed between managers of the three spheres of government, the conducting of an institutional active search of suspected cases, vaccination door to door at alternative times, the use of micro planning, a broad advertising campaign at local media and technical operative support contributed to containing the epidemic. It is important to recognize the possibility of epidemics at this stage of post-elimination and prepare a sensitive surveillance system for timely response.

In Vivo Efficacy of Measles Virus Fusion Protein-Derived Peptides Is Modulated by the Properties of Self-Assembly and Membrane Residence

Measles virus (MV) infection is undergoing resurgence and remains one of the leading causes of death among young children worldwide despite the availability of an effective measles vaccine. MV infects its target cells by coordinated action of the MV hemagglutinin (H) and fusion (F) envelope glycoproteins; upon receptor engagement by H, the prefusion F undergoes a structural transition, extending and inserting into the target cell membrane and then refolding into a postfusion structure that fuses the viral and cell membranes. By interfering with this structural transition of F, peptides derived from the heptad repeat (HR) regions of F can inhibit MV infection at the entry stage. In previous work, we have generated potent MV fusion inhibitors by dimerizing the F-derived peptides and conjugating them to cholesterol. We have shown that prophylactic intranasal administration of our lead fusion inhibitor efficiently protects from MV infection in vivo We show here that peptides tagged with lipophilic moieties self-assemble into nanoparticles until they reach the target cells, where they are integrated into cell membranes. The self-assembly feature enhances biodistribution and the half-life of the peptides, while integration into the target cell membrane increases fusion inhibitor potency. These factors together modulate in vivo efficacy. The results suggest a new framework for developing effective fusion inhibitory peptides.

IMPORTANCE

Measles virus (MV) infection causes an acute illness that may be associated with infection of the central nervous system (CNS) and severe neurological disease. No specific treatment is available. We have shown that fusion-inhibitory peptides delivered intranasally provide effective prophylaxis against MV infection. We show here that specific biophysical properties regulate the in vivo efficacy of MV F-derived peptides.

HIV, breast cancer and vaccines: what do high-profile cases reveal about stakeholder engagement in research?

Substantially engaging stakeholders in research involves making extensive changes to the full life cycle of research, from the initial stage of selecting research priorities to the final stages of dissemination and implementation. Recent scholarship has explored logistical and methodological challenges, including the time, training and resources required for engagement. However, inadequate attention has been given to the intended ends or goals of engagement - what do we want engagement to achieve? An examination of historical case studies can yield important insights regarding engagement and its intended ends. Using historical perspective methods, we explore how clarity about the ends of engagement can inform the design of engagement efforts and lead to better outcomes. We present several lessons for improving stakeholder-engaged research.

Vaccine hesitancy in Austria : A cross-sectional survey

BACKGROUND

Vaccine hesitancy is an emerging phenomenon particularly in industrialized nations. It has led to repeated epidemic outbreaks of otherwise vaccine-preventable, infectious diseases. Compared to other countries very low rates of influenza and measles vaccination rates have been reported in Austria.

METHODS

We performed a single-center cross-sectional, questionnaire-based survey. A total of 350 adult patients attending our emergency room participated in this survey. We assessed knowledge and attitudes towards vaccination and the associated infectious diseases.

RESULTS

Out of 350 participants 40 (11.4 %) declared that they deliberately refused vaccinations. Most common reasons for non-vaccination were fear of adverse effects (35.9 %), doubt of effectiveness of vaccines (35.9 %) and distrust towards the pharmaceutical industry (23.1 %). Of all 350 participants only 148 (42.3 %) thought themselves to be sufficiently informed about national vaccination recommendations as stated in the Austrian National Vaccination Program (ANVP). General practitioners (GP) were the primary source of healthcare-related information for 256 (73.1 %) participants. Furthermore, GPs as well as hospital-based physicians achieved the highest level of trust in this study population.

CONCLUSIONS

The results of our study underline the necessity of comprehensive informational campaigns on the merits of vaccination. A lack of knowledge about the benefits of vaccination, uncertainty and unfounded fears seem to prevent the achievement of recommended vaccination rates. Family GPs enjoyed the highest levels of trust in our study population. We believe that additional information communicated by GPs could help boost the low vaccination rates. This study underlines the important role of primary care practitioners in informing patients about vaccines and healthcare topics.

Health care and human rights: against the split duty gambit

There are various grounds on which one may wish to distinguish a right to health care from a right to health. In this article, I review some old grounds before introducing some new grounds. But my central task is to argue that separating a right to health care from a right to health has objectionable consequences. I offer two main objections. The domestic objection is that separating the two rights prevents the state from fulfilling its duty to maximise the health it provides each citizen from its fixed health budget. The international objection is that separating a human right to health care fails the moral requirement that, for any given moral human right, the substance to which any two right-holders are entitled be of an equal standard.

Adverse Events After MMR or MMRV Vaccine in Infants Under Nine Months Old

BACKGROUND

In the United States, measles is resurging, with more than 700 confirmed cases since January 2014. During measles outbreaks, vaccination as early as at 6 months of age is sometimes recommended for infants who are at risk for exposure.

METHODS

We searched the Vaccine Adverse Event Reporting System for reports of measles, mumps and rubella vaccine combined or measles, mumps, rubella and varicella vaccine combined vaccination in children less than 9 months of age. We performed a clinical assessment of each report and summarized the frequency, range, onset time and severity of adverse events.

RESULTS

After excluding 346 reports because they were duplicates or because they contained insufficient information about the child's age or vaccine(s), we retained 204 reports in the analysis, including 35 (17%) that were serious. Among the 169 nonserious reports, more than half (88; 52%) described a vaccination error without any adverse event per se. Other nonserious reports described fever, injection reactions and gastrointestinal symptoms. Serious adverse events included developmental disorders, fever and fussiness. There were 44 reports of fever, but only 4 cases began 5-12 days after immunization, the peak risk window. The vast majority of fever reports listed concomitant vaccines, such as diphtheria and tetanus toxoids, acellular or whole-cell pertussis vaccine.

CONCLUSIONS

This review did not identify any major safety concerns. These findings may facilitate discussions about the risks and benefits of vaccinating infants who are potentially exposed to this life-threatening disease.

Vaccine epidemiology: A review

This review article outlines the key concepts in vaccine epidemiology, such as basic reproductive numbers, force of infection, vaccine efficacy and effectiveness, vaccine failure, herd immunity, herd effect, epidemiological shift, disease modeling, and describes the application of this knowledge both at program levels and in the practice by family physicians, epidemiologists, and pediatricians. A case has been made for increased knowledge and understanding of vaccine epidemiology among key stakeholders including policy makers, immunization program managers, public health experts, pediatricians, family physicians, and other experts/individuals involved in immunization service delivery. It has been argued that knowledge of vaccine epidemiology which is likely to benefit the society through contributions to the informed decision-making and improving vaccination coverage in the low and middle income countries (LMICs). The article ends with suggestions for the provision of systematic training and learning platforms in vaccine epidemiology to save millions of preventable deaths and improve health outcomes through life-course.

To spray or not to spray? Understanding participation in an indoor residual spray campaign in Arequipa, Peru

Current low participation rates in vector control programmes in Arequipa, Peru complicate the control of Chagas disease. Using focus groups (n = 17 participants) and semi-structured interviews (n = 71) conducted in March and May 2013, respectively, we examined barriers to and motivators of household participation in an indoor residual spray (IRS) campaign that had taken place one year prior in Arequipa. The most common reported barriers to participation were inconvenient spray times due to work obligations, not considering the campaign to be necessary, concerns about secondary health impacts (e.g. allergic reactions to insecticides), and difficulties preparing the home for spraying (e.g. moving heavy furniture). There was also a low perception of risk for contracting Chagas disease that might affect participation. The main motivator to participate was to ensure personal health and well-being. Future IRS campaigns should incorporate more flexible hours, including weekends; provide appropriate educational messages to counter concerns about secondary health effects; incorporate peer educators to increase perceived risk to Chagas in community; obtain support from community members and leaders to build community trust and support for the campaign; and assist individuals in preparing their homes. Enhancing community trust in both the need for the campaign and its operations is key.

Just when you think you know someone: the evolving epidemiologies of measles and pertussis

PURPOSE OF REVIEW

The epidemiologic patterns of measles and pertussis continue to evolve in the United States. Recent studies have provided important insights which impact the public health response to these diseases.

RECENT FINDINGS

An increase in imported cases has led to increased reports of measles disease in the United States. The burden of pertussis disease is shifting to schoolchildren who have received only acellular vaccinations as part of their childhood series.

SUMMARY

Routine childhood vaccinations protect against these diseases, but have limitations which should be recognized. Medical providers and public health practitioners will need to work together to ensure that patients are educated about the importance of vaccines, and that these vaccines are available to those who need them.

Measles in the 21st Century, a Continuing Preventable Risk to Travelers: Data From the GeoSentinel Global Network

Measles remains a risk for travelers, with 94 measles diagnoses reported to the GeoSentinel network from 2000 to 2014, two-thirds since 2010. Asia was the most common exposure region, then Africa and Europe. Efforts to reduce travel-associated measles should target all vaccine-eligible travelers, including catch-up vaccination of susceptible adults.

Robust Vaccine Responses in Adult and Pediatric Cord Blood Transplantation Recipients Treated for Hematologic Malignancies

Because cord blood (CB) lacks memory T and B cells and recent decreases in herd immunity to vaccine-preventable diseases in many developed countries have been documented, vaccine responses in CB transplantation (CBT) survivors are of great interest. We analyzed vaccine responses in double-unit CBT recipients transplanted for hematologic malignancies. In 103 vaccine-eligible patients, graft-versus-host disease (GVHD) most commonly precluded vaccination. Sixty-five patients (63%; engrafting units median HLA-allele match 5/8; range, 2 to 7/8) received protein conjugated vaccines, and 63 patients (median age, 34 years; range, .9 to 64) were evaluated for responses. Median vaccination time was 17 months (range, 7 to 45) post-CBT. GVHD (n = 42) and prior rituximab (n = 13) delayed vaccination. Responses to Prevnar 7 and/or 13 vaccines (serotypes 14, 19F, 23F) were seen in children and adults (60% versus 49%, P = .555). Responses to tetanus, diphtheria, pertussis, Haemophilus influenzae, and polio were observed in children (86% to 100%) and adults (53% to 89%) even if patients had prior GVHD or rituximab. CD4(+)CD45RA(+) and CD19(+) cell recovery significantly influenced tetanus and polio responses. In a smaller cohort responses were seen to measles (65%), mumps (50%), and rubella (100%) vaccines. No vaccine side effects were identified, and all vaccinated patients survived (median follow-up, 57 months). Although GVHD and rituximab can delay vaccination, CBT recipients (including adults and those with prior GVHD) have similar vaccine response rates to adult donor allograft recipients supporting vaccination in CBT recipients.

The Reemergence of Measles

Measles, or rubeola, is a highly infectious, acute viral illness of childhood that is considered eliminated in the USA but has reemerged in the past few years. Globally, an estimated 20 million cases of measles continue to occur, and it remains a leading cause of death among young children. It is rare in the USA and other first world countries, but numerous outbreaks have occurred in the USA recently, due to a combination of factors including poor vaccine coverage and importation of cases among travelers returning from endemic areas. The diagnosis of measles is usually made clinically, when an individual presents with a constellation of symptoms including cough, coryza, conjunctivitis, high fever, and an erythematous maculopapular rash in a cephalocaudal distribution. Complications are common and include otitis media, pneumonia, encephalitis, and rarely death. A measles vaccine is available in two doses and provides excellent protection against the disease. Despite this, vaccination coverage, especially among young adults, remains poor. Given its resurgence in the USA and other countries, interventions are urgently needed to address low vaccination rates and vaccine hesitancy. Measles awareness should also be a priority among young clinicians, who may have never seen a case or are not familiar with the disease.

Immunity to Measles, Mumps, and Rubella in US Children With Perinatal HIV Infection or Perinatal HIV Exposure Without Infection

BACKGROUND

Children with perinatal human immunodeficiency virus (HIV) infection (PHIV) may not be protected against measles, mumps, and rubella (MMR) because of impaired initial vaccine response or waning immunity. Our objectives were to estimate seroimmunity in PHIV-infected and perinatally HIV-exposed but uninfected (HEU) children and identify predictors of immunity in the PHIV cohort.

METHODS

PHIV and HEU children were enrolled in the Pediatric HIV/AIDS Cohort Study (PHACS) at ages 7-15 years from 2007 to 2009. At annual visits, demographic, laboratory, immunization, and clinical data were abstracted and serologic specimens collected. Most recent serologic specimen was used to determine measles seroprotection by plaque reduction neutralization assay and rubella seroprotection and mumps seropositivity by enzyme immunoassay. Sustained combination antiretroviral therapy (cART) was defined as taking cART for at least 3 months.

RESULTS

Among 428 PHIV and 221 HEU PHACS participants, the prevalence was significantly lower in PHIV children for measles seroprotection (57% [95% confidence interval {CI}, 52%-62%] vs 99% [95% CI, 96%-100%]), rubella seroprotection (65% [95% CI, 60%-70%] vs 98% [95% CI, 95%-100%]), and mumps seropositivity (59% [95% CI, 55%-64%] vs 97% [95% CI, 94%-99%]). On multivariable analysis, greater number of vaccine doses while receiving sustained cART and higher nadir CD4 percentage between last vaccine dose and serologic testing independently improved the cumulative prediction of measles seroprotection in PHIV. Predictors of rubella seroprotection and mumps seropositivity were similar.

CONCLUSIONS

High proportions of PHIV-infected children, but not HEU children, lack serologic evidence of immunity to MMR, despite documented immunization and current cART. Effective cART before immunization is a strong predictor of current seroimmunity.