Association of Previous Measles Infection With Markers of Acute Infectious Disease Among 9- to 59-Month-Old Children in the Democratic Republic of the Congo

Immunological landscape of human lymphoid explants during measles virus infection

In humans, lymph nodes are the primary site of measles virus (MeV) replication. To understand the immunological events that occur at this site, we infected human lymphoid tissue explants using a pathogenic strain of MeV that expresses GFP. We found that MeV infected 5%-15% of cells across donors. Using single-cell RNA-Seq and flow cytometry, we found that while most of the 29 cell populations identified in the lymphoid culture were susceptible to MeV, there was a broad preferential infection of B cells and reduced infection of T cells. Further subsetting of T cells revealed that this reduction may be driven by the decreased infection of naive T cells. Transcriptional changes in infected B cells were dominated by an interferon-stimulated gene (ISG) signature. To determine which of these ISGs were most substantial, we evaluated the proteome of MeV-infected Raji cells by mass spectrometry. We found that IFIT1, IFIT2, IFIT3, ISG15, CXCL10, MX2, and XAF1 proteins were the most highly induced and positively correlated with their expression in the transcriptome. These data provide insight into the immunological events that occur in lymph nodes during infection and may lead to the development of therapeutic interventions.

Ongoing Measles in the Developed and Developing World

Measles is a vaccine-preventable illness. Nevertheless, in recent years, measles is still endemic and epidemic in both the developed world and the developing world. The public perception of measles in the past was that it was not a big deal. However, measles is associated with a number of complications which can be places in three categories which are: acute(diarrhea, otitis media, pneumonia, encephalitis, seizures, and death) and delayed-subacute sclerosing panencephalitis (SSPE) and post-measles immune amnesia. Contrary to the beliefs of the anti-vaccine lobby, measles is bad. In acute measles, the death rate is 1-3 per 1000 and the risk of encephalitis is 1 per 1000. Relatively recent investigations indicate that SSPE is considerably more common than previously believed. The worldwide contribution of post-measles immune amnesia to morbidity and mortality is likely to be huge. In exposure situations, two doses of measles vaccine will prevent 99% of cases. Presently in the United States, the first dose is given at 12 through 15 months of age. The second dose is most often administered at 4 through 6 years of age. In my opinion, the second dose of measles vaccine should be given 4-6 weeks after the first dose rather than at 4-6 years of age. Children who don't have antibody to measles should not travel to risk areas.

Measles outbreak in the adult age group: Clinical, laboratory, and epidemiological features of the 11 patients admitted to the hospital

The measles virus, also known as the morbillivirus, or MV, is a virus that infects humans. The goal of this research is to assess to adult cases of measles. Eleven patients thought to be confirmed cases of measles were enrolled in the investigation. Following the identification of symptoms of tiredness, fever, and rash in one soldier, the results of 10 more troops from the pertinent military group were assessed. The diagnosis was made based on the presence of serum immunoglobulin M (IgM) and positive polymerase chain reaction (PCR) results. When the control IgM, immunoglobulin G, and PCR findings were evaluated a fortnight after hospitalization, a cluster of 11 incidents was found. It is now necessary to address the issue of the cautious stance towards vaccination or the anti-vaccination sentiment that has grown increasingly popular, particularly in light of the COVID-19 pandemic, for both our nation and the entire world.

Measles vaccination and reduced child mortality: Prevention of immune amnesia or beneficial non-specific effects of measles vaccine?

Measles vaccine (MV) has been observed to reduce all-cause mortality more than explained by prevention of measles infection. Recently, prevention of "measles-induced immune amnesia" (MIA) has been proposed as an explanation for this larger-than-anticipated beneficial effect of measles vaccine (MV). According to the "MIA hypothesis", immune amnesia leads to excess non-measles morbidity and mortality, that may last up to five years after measles infection, but may be prevented by MV. However, the benefits of MV-vaccinated children could also be due to beneficial non-specific effects (NSEs) of MV, reducing the risk of non-measles infections (The "NSE hypothesis"). The epidemiological studies do provide some support for MIA, as exposure to measles infection before 6 months of age causes long-term MIA, and over 6 months of age for 2-3 months. However, in children over 6 months of age, the MIA hypothesis is contradicted by several epidemiological patterns: First, in community studies that adjusted for MV status, children surviving acute measles infection had lower mortality than uninfected controls (44%(95%CI: 0-69%)). Second, in six randomised trials and six observational studies comparing MV-vaccinated and MV-unvaccinated children, the benefit of MV changed minimally from 54%(43-63%) to 49%(37-59%) when measles cases were censored in the survival analysis, making it unlikely that prevention of measles and its long-term consequences explained much of the reduced mortality. Third, several studies conducted in measles-free contexts still showed significantly lower mortality after MV (55%(40-67%)). Fourth, administration of MV in the presence of maternal measles antibody (MatAb) is associated with much stronger beneficial effect for child survival than administration of MV in the absence of MatAb (55%(35-68%) lower mortality). The MIA hypothesis alone cannot explain the strongly beneficial effects of MV on child survival. Conversely, the hypothesis that MV has beneficial non-specific immune training effects is compatible with all available data. Consideration should be given to continuing MV even when measles has been eradicated.

Reported History of Measles and Long-term Impact on Tetanus Antibody Detected in Children 9-59 Months of Age and Receiving 3 Doses of Tetanus Vaccine in the Democratic Republic of the Congo

BACKGROUND

Recent studies suggest measles-induced immune amnesia could have long-term immunosuppressive effects via preferential depletion of memory CD150+ lymphocytes, and associations with a 2-3 year period of increased mortality and morbidity from infectious diseases other than measles has been shown in children from wealthy and low-income countries. To further examine the associations previous measles virus infection may have on immunologic memory among children in the Democratic Republic of the Congo (DRC), we assessed tetanus antibody levels among fully vaccinated children, with and without a history of measles.

METHODS

We assessed 711 children 9-59 months of age whose mothers were selected for interview in the 2013-2014 DRC Demographic and Health Survey. History of measles was obtained by maternal report and classification of children who had measles in the past was completed using maternal recall and measles IgG serostatus obtained from a multiplex chemiluminescent automated immunoassay dried blood spot analysis. Tetanus IgG antibody serostatus was similarly obtained. A logistic regression model was used to identify association of measles and other predictors with subprotective tetanus IgG antibody.

RESULTS

Subprotective geometric mean concentration tetanus IgG antibody values were seen among fully vaccinated children 9-59 months of age, who had a history of measles. Controlling for potential confounding variables, children classified as measles cases were less likely to have seroprotective tetanus toxoid antibody (odds ratio: 0.21; 95% confidence interval: 0.08-0.55) compared with children who had not had measles.

CONCLUSIONS

History of measles was associated with subprotective tetanus antibody among this sample of children in the DRC who were 9-59 months of age and fully vaccinated against tetanus.

Assessing the Effects of Measles Virus Infections on Childhood Infectious Disease Mortality in Brazil

BACKGROUND

Measles virus infection induces acute immunosuppression for weeks following infection, and also impairs preexisting immunological memory, resulting in "immune amnesia" that can last for years. Both mechanisms predispose the host to severe outcomes of subsequent infections. Therefore, measles dynamics could potentially affect the epidemiology of other infectious diseases.

METHODS

To examine this hypothesis, we analyzed the annual mortality rates of children aged 1-9 years in Brazil from 1980 to 1995. We calculated the correlation between nonmeasles infectious disease mortality rates and measles mortality rates using linear and negative-binomial models, with 3 methods to control the confounding effects of time. We also estimated the duration of measles-induced immunomodulation.

RESULTS

The mortality rates of nonmeasles infectious diseases and measles virus infection were highly correlated. This positive correlation remained significant after removing the time trends. We found no evidence of long-term measles immunomodulation beyond 1 year.

CONCLUSIONS

These results support that measles virus infection could increase the mortality of other infectious diseases. The short lag identified for measles effects (<1 year) implies that acute immunosuppression was potentially driving this effect in Brazil. Overall, our study indicates disproportionate contributions of measles to childhood infectious disease mortality, highlighting the importance of measles vaccination.

Disease Progression, Clinical Features, and Risk Factors for Pneumonia in Unvaccinated Children and Adolescents with Measles: A Re-Emerging Disease in Romania

Measles causes in vaccinated children, with some exceptions, a mild disease, while the unvaccinated can suffer complications that result in serious consequences and even death. Although the introduction of the measles vaccine has reduced the number of cases and the viral spread, the current downward vaccination trend has resulted in the resurgence of the disease. Currently, Romania has a measles vaccination coverage below the 95% safety threshold. Thus, an outbreak started in 2016 and still ongoing in Romania, many cases being identified in the Western region in the pediatric population. Our objective was to conduct a thorough examination of clinical characteristics, evolution, and risk factors in vaccinated and unvaccinated children in this region. To reach our objectives we used a retrospective cohort analysis. The authors reviewed clinical and laboratory data from patients hospitalized at "Victor Babes" Hospital for Infectious Diseases and Pulmonology in Timisoara. We found a total of 136 qualifying cases of measles among the children admitted to this facility. The two comparison groups consisted of 104 children under 10 years and 32 patients between 10 and 18 years. An important characteristic of both study groups was the high prevalence of patients from the Roma ethnicity, which, although represents a minority in Romania, the prevalence was over 40% in the current study. The infection source was in 40.4% of children under 10 years inside the family, while 71.9% of infections in the group of adolescents were isolated (p-value = 0.047). The multivariate risk factor analysis identified as independent risk factors for the development of pneumonia the older age of patients (OR = 1.62), poor nutritional status (OR = 1.25), Roma ethnicity (OR = 2.44), presence of anemia (OR = 1.58), and procalcitonin (OR = 3.09). It is essential to handle these risk factors in a patient with measles, especially in conjunction with an unknown vaccination status. To achieve a vaccination rate greater than 95 percent for Romanian children, measles vaccination awareness must be promoted, moreover in the Roma population. More comprehensive preventative methods must be developed promptly with the objective of eradicating measles in Romania via a vigorous vaccination campaign.

Measles in the European Past: Outbreak of Severe Measles in an Isolated German Village, 1861

OBJECTIVES

We examined measles mortality in the European past in an outbreak in an isolated German village, Hagelloch, in 1861.

METHODS

Pfeilsticker's contemporary thesis was used to describe the measles case fatality ratio (CFR) and complications. Data on onset of prodromes and rash was used to determine index cases and secondary cases of measles within the household. The church register provided information on survival in 1862.

RESULTS

The epidemic affected nearly all children under 14 years of age. The overall CFR was 6.4%(12/187), and 10%(7/70) for children under five years of age; 44% of children were secondary cases (82/187). Secondary cases had higher CFR than index cases (RR=3.03 (95% CI: 0.91-10.07). Boys had higher CFR than girls (RR=4.46 (1.03-19.22)). Boys infected by a girl had higher CFR than boys infected by other boys (RR=6.30 (1.18-85.64)). Children who survived measles virus infection in 1861, did not have higher mortality in the following year compared with those who had not had measles in 1861 (RR=0.24 (0.07-0.82)).

CONCLUSIONS

Severe measles in the European past had determinants similar to those observed more recently in low-income countries.

BRIEF SUMMARY

The measles case fatality was 6% in rural Germany in 1861. Mortality was highest for boys infected in the household by a girl. There was no excess mortality after the acute phase of measles infection.

Effect of measles prevalence and vaccination coverage on other disease burden: evidence of measles immune amnesia in 46 African countries

BACKGROUND

Measles is highly infectious that leads to a high disease burden among the vulnerable population, especially in developing countries, despite the availability of highly effective measles vaccine. Immune amnesia, the resetting of the immune systems of infected patients, has been observed in developed countries. This paper is the first to use various African countries to evaluate the extent of immune amnesia.

METHODS

We used two panel datasets from 46 African countries between 1990 and 2018 among children, one is the disease prevalence from Global Burden of Disease, and another is on the measles vaccination coverage from WHO/UNICEF Joint Reporting Form. We used panel regression to estimate the effect of measles prevalence or measles vaccination coverage on other disease prevalence (diarrhea, lower respiratory infection, malaria, meningitis, and tuberculosis).

RESULTS

We found the strong evidence that the increase in the measles prevalence led to an increase in other disease prevalence and mortality. We also found that the increase in the measles vaccination coverage decreased the prevalence of and the mortality due to other diseases.

DISCUSSION AND CONCLUSION

Measles vaccination can have a large impact on children's health because not only does it reduce the prevalence of measles cases and deaths but also could it potentially reduce the prevalence of and deaths due to other diseases.

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

Background

Measles is endemic in the Democratic Republic of the Congo (DRC), and 89–94% herd immunity is required to halt its transmission. Much of the World Health Organization African Region, including the DRC, has vaccination coverage below the 95% level required to eliminate measles, heightening concern of inadequate measles immunity.

Methods

We assessed 6706 children aged 6–59 months whose mothers were selected for interview in the 2013–2014 DRC Demographic and Health Survey. History of measles was obtained by maternal report, and classification of children who had measles was completed using maternal recall and measles immunoglobulin G serostatus obtained from a multiplex chemiluminescent automated immunoassay dried blood spot analysis. A logistic regression model was used to identify associations of covariates with measles and seroprotection, and vaccine effectiveness (VE) was calculated.

Results

Out of our sample, 64% of children were seroprotected. Measles vaccination was associated with protection against measles (OR: 0.15, 95% CI: 0.03, 0.81) when administered to children 12 months of age or older. Vaccination was predictive of seroprotection at all ages. VE was highest (88%) among children 12–24 months of age.

Conclusion

Our results demonstrated lower than expected seroprotection against measles among vaccinated children. Understanding the factors that affect host immunity to measles will aid in developing more efficient and effective immunization programs in DRC.

The potential impact of a recent measles epidemic on COVID-19 in Samoa

BACKGROUND

The pandemic of COVID-19 has occurred close on the heels of a global resurgence of measles. In 2019, an unprecedented epidemic of measles affected Samoa, requiring a state of emergency to be declared. Measles causes an immune amnesia which can persist for over 2 years after acute infection and increases the risk of a range of other infections.

METHODS

We modelled the potential impact of measles-induced immune amnesia on a COVID-19 epidemic in Samoa using data on measles incidence in 2018-2019, population data and a hypothetical COVID-19 epidemic.

RESULTS

The young population structure and contact matrix in Samoa results in the most transmission occurring in young people < 20 years old. The highest rate of death is the 60+ years old, but a smaller peak in death may occur in younger people, with more than 15% of total deaths in the age group under 20 years old. Measles induced immune amnesia could increase the total number of cases by 8% and deaths by more than 2%.

CONCLUSIONS

Samoa, which had large measles epidemics in 2019-2020 should focus on rapidly achieving high rates of measles vaccination and enhanced surveillance for COVID-19, as the impact may be more severe due to measles-induced immune paresis. This applies to other severely measles-affected countries in the Pacific, Europe and elsewhere.

Communicating Benefits from Vaccines Beyond Preventing Infectious Diseases

Despite immunisation being one of the greatest medical success stories of the twentieth century, there is a growing lack of confidence in some vaccines. Improving communication about the direct benefits of vaccination as well as its benefits beyond preventing infectious diseases may help regain this lost confidence. A conference was organised at the Fondation Merieux in France to discuss what benefits could be communicated and how innovative digital initiatives can used for communication. During this meeting, a wide range of indirect benefits of vaccination were discussed. For example, influenza vaccination can reduce hospitalisations and deaths in older persons with diabetes by 45% and 38%, respectively, but the link between influenza and complications from underlying chronic non-communicable diseases such as diabetes is frequently underestimated. Vaccination can reduce antimicrobial resistance (AMR), which is growing, by reducing the incidence of infectious disease (though direct and indirect or herd protection), by reducing the number of circulating AMR strains, and by reducing the need for antimicrobial use. Disease morbidity and treatment costs in the elderly population are likely to rise substantially, with the ageing global population. Healthy ageing and life-course vaccination approaches can reduce the burden of vaccine-preventable diseases, such as seasonal influenza and pneumococcal diseases, which place a significant burden on individuals and society, while improving quality of life. Novel disease surveillance systems based on information from Internet search engines, mobile phone apps, social media, cloud-based electronic health records, and crowd-sourced systems, contribute to improved awareness of disease burden. Examples of the role of new techniques and tools to process data generated by multiple sources, such as artificial intelligence, to support vaccination programmes, such as influenza and dengue, were discussed. The conference participants agreed that continual efforts are needed from all stakeholders to ensure effective, transparent communication of the full benefits and risks of vaccination.

The Susceptibility to Other Infectious Diseases Following Measles During a Three Year Observation Period in Switzerland

BACKGROUND

Measles virus infection leads to significant immunosuppression. In developing countries, this translates to an increased nonspecific mortality, whereas its effects in developed countries are less clear.

METHODS

We performed a cohort study to investigate whether children hospitalized with measles (cases) between 2000 and 2015 in Switzerland would have a higher frequency of hospital admissions due to other infectious diseases thereafter than children who did not have measles (controls). Cases were identified by ICD-10 discharge diagnoses for measles and/or keyword search and matched to 2 controls by time of hospitalization, age and sex. All hospitalizations ≤3 years after original admission, infectious or noninfectious in origin, were identified in cases and controls.

RESULTS

One hundred thirteen cases (56% males), mean age 9.0 years (range 2 weeks-17.8 years), and 196 controls were identified. Twelve rehospitalizations due to an infectious disease occurred in 11 cases and 6 in 6 controls (episode rates 0.106 versus 0.031 per person; ratio 3.47; 95% CI: 1.20-11.3; P = 0.012) in 3 years of follow-up. Of these, 9 and 3 occurred in cases and controls, respectively, during year 1 [ratio 5.20 (95% CI: 1.30-29.88; P = 0.012)]. Infectious diseases following measles affected various organ systems, were neither particularly severe nor fatal and revealed no specific pattern.

CONCLUSIONS

The increased risk for nonspecific infectious disease hospitalizations supports the concept of immunologic amnesia after measles. Universal immunization against measles provides additional benefit beyond protection against measles itself.

Response to Comment on "Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality"

Thakkar and McCarthy suggest that periodicity in measles incidence artifactually drives our estimates of a 2- to 3-year duration of measles "immune-amnesia." We show that periodicity has a negligible effect relative to the immunological signal we detect, and demonstrate that immune-amnesia is largely undetectable in small populations with large fluctuations in mortality of the type they use for illustration.