Mpox neglect and the smallpox niche: a problem for Africa, a problem for the world.

Mpox (formerly known as monkeypox) is a zoonotic viral disease endemic in parts of Africa. In May, 2022, the world was alerted to circulation of monkeypox virus in many high-income countries outside of Africa. Continued spread resulted in a WHO declaration of a Public Health Emergency of International Concern. Although there has been much attention on the global outbreak, most of the focus has been on high-income countries outside of Africa, despite the fact that monkeypox virus has been causing disease in parts of Africa for at least 50 years. Furthermore, the long-term consequences of this event, especially the risk that mpox fills the niche vacated through smallpox eradication, have not been sufficiently considered. The heart of the problem is the historical neglect of mpox in Africa where the disease is endemic, and the actual and potential consequences if this neglect is left uncorrected.

Evaluation of monkeypox- and vaccinia-virus neutralizing antibodies before and after smallpox vaccination: A sero-epidemiological study.

Since May 2022, several countries outside of Africa experienced multiple clusters of monkeypox virus (MPXV)-associated disease. In the present study, anti-MPXV and anti-vaccinia virus (VACV) neutralizing antibody responses were evaluated in two cohorts of subjects from the general Italian population (one half born before the WHO-recommended end of smallpox vaccination in 1980, the other half born after). Higher titers (either against MPXV or VACV) were observed in the cohort of individuals born before the interruption of VACV vaccination. An association between VACV and MPXV antibody levels was observed, suggesting that the smallpox vaccination may confer some degree of cross-protection against MPXV infection. Results from this study highlight low levels of immunity toward the assessed Orthopoxviruses, especially in young adults, advocating the introduction of a VACV- or MPXV-specific vaccine in case of resurgence of monkeypox disease outbreaks.

Tracing the journey of poxviruses: insights from history.

The historical significance of the poxviruses is profound, largely due to the enduring impact left by smallpox virus across many centuries. The elimination of smallpox is a remarkable accomplishment in the history of science and medicine, with centuries of devoted efforts resulting in the development and widespread administration of smallpox vaccines. This review provides insight into the pivotal historical events involving medically significant poxviruses. Understanding the remarkable saga of combatting smallpox is crucial, serving as a guidepost for potential future encounters with poxvirus infections. There is a continual need for vigilant observation of poxvirus evolution and spillover from animals to humans, considering the expansive range of susceptible hosts. The recent occurrence of monkeypox cases in non-endemic countries stands as a stark reminder of the ease with which infections can be disseminated through international travel and trade. This backdrop encourages introspection about our journey and the current status of poxvirus research.

Effect of prior immunisation with smallpox vaccine for protection against human Mpox: A systematic review.

Monkeypox is an emerging threat to humans since a new outbreak in May 2022. It is hypothesised that increasing the immunologically naive population after the cessation of the smallpox vaccination campaign in the 1980s is one of the leading causes of it. A literature search was conducted using different electronic databases including MEDLINE (through PubMed), SCOPUS, Web of Science, Cochrane library, and EMBASE for relevant studies. After duplication removal, abstract and title screening, and full-text screening were done, the data were extracted, tabulated, and analysed. The risk of bias was assessed following the Risk of Bias Assessment tool for Non-randomised Studies. We found a total of 1068 relevant articles and finally, we included 6 articles including 2083 participants. The studies suggested that smallpox is 80.7% efficacious to prevent human monkeypox and the immunity provided by prior smallpox vaccination is long-lasting. Moreover, the smallpox vaccination decreases the risk of human monkeypox by 5.2-folds. Two cross-sectional studies based on the Democratic Republic of the Congo (DRC) including a total of around 1800 monkeypox cases found that unvaccinated participants had 2.73 and 9.64-fold increased risk of monkeypox compared to the vaccinated participants. Other studies in USA and Spain also demonstrated that unvaccinated people were more prone to develop monkeypox than vaccinated people. Furthermore, monkeypox incidence has increased by 20 folds, 30 years after the cessation of the smallpox vaccination campaign in DRC. Evidence-based preventive and therapeutic agents are still not available for human monkeypox. Further study should be done to explore the role of the smallpox vaccine in preventing human monkeypox.

Role of the Laboratory in the Diagnosis of Poxvirus Infections.

Although WHO-led global efforts led to eradication of smallpox over four decades ago, other poxviruses, especially monkeypox, have re-emerged to occupy the ecological niche vacated by smallpox. Many of these viruses produce similar lesions thus mandating a prompt laboratory confirmation. There has been considerable evolution in the techniques available to diagnose these infections and differentiate between them. With the 2022 multi-country outbreak of monkeypox, significant efforts were made to apprise the laboratory diagnosis of the virus and numerous real-time-PCR-based assays were made commercially available. This chapter discusses the sample collection and biosafety aspects along with the repertoire of diagnostic modalities, both traditional and emerging, for poxviruses which a special focus on monkeypox. The advantages and disadvantages of each technique have been illustrated. We have also reflected upon the newer advances and the existing lacunae.

Poxvirus Vaccines: Past, Present, and Future.

Smallpox was a significant cause of mortality for over three thousand years, amounting to 10% of deaths yearly. Edward Jenner discovered smallpox vaccination in 1796, which rapidly became a smallpox infection preventive practice throughout the world and eradicated smallpox infection by 1980. After smallpox eradication, monkeypox vaccines have been used primarily in research and in outbreaks in Africa, where the disease is endemic. In the present, the vaccines are being used for people who work with animals or in high-risk areas, as well as for healthcare workers treating patients with monkeypox. Among all orthopoxviruses (OPXV), monkeypox viral (MPXV) infection occurs mainly in cynomolgus monkeys, natural reservoirs, and occasionally causes severe multi-organ infection in humans, who were the incidental hosts. The first case of the present epidemic of MXPV was identified on May 7, 2022, and rapidly increased the number of cases. In this regard, the WHO declared the outbreak, an international public health emergency on July 23, 2022. The first monkeypox vaccine was developed in the 1960s by the US Army and was based on the vaccinia virus, which is also used in smallpox vaccines. In recent years, newer monkeypox vaccines have been developed based on other viruses such as Modified Vaccinia Ankara (MVA). These newer vaccines are safer and can provide longer-lasting immunity with fewer side effects. For the future, there is ongoing research to improve the current vaccines and to develop new ones. One notable advance has been the development of a recombinant vaccine that uses a genetically modified vaccinia virus to express monkeypox antigens. This vaccine has shown promising results in pre-clinical trials and is currently undergoing further testing in clinical trials. Another recent development has been the use of a DNA vaccine, which delivers genetic material encoding monkeypox antigens directly into cells. This type of vaccine has shown effectiveness in animal studies and is also undergoing clinical testing in humans. Overall, these recent advances in monkeypox vaccine development hold promise for protecting individuals against this potentially serious disease.

Treatment and Vaccination for Smallpox and Monkeypox.

The smallpox infection with the variola virus was one of the most fatal disorders until a global eradication was initiated in the twentieth century. The last cases were reported in Somalia 1977 and as a laboratory infection in the UK 1978; in 1980, the World Health Organization (WHO) declared smallpox for extinct. The smallpox virus with its very high transmissibility and mortality is still a major biothreat, because the vaccination against smallpox was stopped globally in the 1980s. For this reason, new antivirals (cidofovir, brincidofovir, and tecovirimat) and new vaccines (ACAM2000, LC16m8 and Modified Vaccine Ankara MVA) were developed. For passive immunization, vaccinia immune globulin intravenous (VIGIV) is available. Due to the relationships between orthopox viruses such as vaccinia, variola, mpox (monkeypox), cowpox, and horsepox, the vaccines (LC16m8 and MVA) and antivirals (brincidofovir and tecovirimat) could also be used in the mpox outbreak with positive preliminary data. As mutations can result in drug resistance against cidofovir or tecovirimat, there is need for further research. Further antivirals (NIOCH-14 and ST-357) and vaccines (VACΔ6 and TNX-801) are being developed in Russia and the USA. In conclusion, further research for treatment and prevention of orthopox infections is needed and is already in progress. After a brief introduction, this chapter presents the smallpox and mpox disease and thereafter full overviews on antiviral treatment and vaccination including the passive immunization with vaccinia immunoglobulins.

Effectiveness of historical smallpox vaccination against mpox clade II in men in Denmark, France, the Netherlands and Spain, 2022.

BackgroundIn 2022, a global monkeypox virus (MPXV) clade II epidemic occurred mainly among men who have sex with men. Until early 1980s, European smallpox vaccination programmes were part of worldwide smallpox eradication efforts. Having received smallpox vaccine > 20 years ago may provide some cross-protection against MPXV.AimTo assess the effectiveness of historical smallpox vaccination against laboratory-confirmed mpox in 2022 in Europe.MethodsEuropean countries with sufficient data on case vaccination status and historical smallpox vaccination coverage were included. We selected mpox cases born in these countries during the height of the national smallpox vaccination campaigns (latest 1971), male, with date of onset before 1 August 2022. We estimated vaccine effectiveness (VE) and corresponding 95% CI for each country using logistic regression as per the Farrington screening method. We calculated a pooled estimate using a random effects model.ResultsIn Denmark, France, the Netherlands and Spain, historical smallpox vaccination coverage was high (80-90%) until the end of the 1960s. VE estimates varied widely (40-80%, I2 = 82%), possibly reflecting different booster strategies. The pooled VE estimate was 70% (95% CI: 23-89%).ConclusionOur findings suggest residual cross-protection by historical smallpox vaccination against mpox caused by MPXV clade II in men with high uncertainty and heterogeneity. Individuals at high-risk of exposure should be offered mpox vaccination, following national recommendations, regardless of prior smallpox vaccine history, until further evidence becomes available. There is an urgent need to conduct similar studies in sub-Saharan countries currently affected by the MPXV clade I outbreak.

Lessons From a House on Fire-From Smallpox to Polio.

Global burden of disease morbidity and mortality has shifted dramatically in the last 30 years from infectious to non-communicable diseases, leading to major improvements in global child survival and enhanced life expectancy for all age groups. Vaccination efforts worldwide have been key to this achievement, but with a reduction in vaccine preventable diseases, anti-vaccine sentiments have concurrently increased. Eradication of smallpox in 1977 is a testament to vaccination impacts on human health. Despite this historic success, recent increases in infectious disease outbreaks, such as polio and measles, especially among poorly vaccinated populations, have underscored the risks of resurgence of diseases once thought eliminated in the United States and elsewhere. Engaging governments, community leaders, and the public will be critical to continuing the advancement of global health through elimination of vaccine preventable diseases.

Re-emerging human monkeypox: A major public-health debacle.

A multicountry outbreak of the monkeypox virus has gained global attention. As of May 25, 250 confirmed human monkeypox cases have been reported globally. Monkeypox is caused by the Monkeypox virus, which belongs to the Orthopoxvirus genus and Poxviridae family. Monkeypox is often a self-limiting infection, with symptoms lasting 2-4 weeks with the case fatality ratio around 3%-6%. Monkeypox is transmitted to humans by direct contact with an infected person or animal or contact with virus-contaminated material. Human monkeypox infections may lead to various medical complications such as fever, rash, and lymphadenopathies. Pneumonitis, encephalitis, sight-threatening keratitis, and subsequent bacterial infections are all possible complications of monkeypox. An antiviral agent developed to treat smallpox has also been approved for use in the treatment of monkeypox in the United States. Vaccines used in the smallpox eradication program also provided immunity to monkeypox. Newer vaccines have been developed, one of which has been approved for monkeypox prevention. In this study, we provide information about the recent outbreaks of human monkeypox, epidemiology, transmission pattern, possible diagnosis techniques, therapeutics, and available preventive strategies.

Patterns of smallpox mortality in London, England, over three centuries.

Smallpox is unique among infectious diseases in the degree to which it devastated human populations, its long history of control interventions, and the fact that it has been successfully eradicated. Mortality from smallpox in London, England was carefully documented, weekly, for nearly 300 years, providing a rare and valuable source for the study of ecology and evolution of infectious disease. We describe and analyze smallpox mortality in London from 1664 to 1930. We digitized the weekly records published in the London Bills of Mortality (LBoM) and the Registrar General's Weekly Returns (RGWRs). We annotated the resulting time series with a sequence of historical events that might have influenced smallpox dynamics in London. We present a spectral analysis that reveals how periodicities in reported smallpox mortality changed over decades and centuries; many of these changes in epidemic patterns are correlated with changes in control interventions and public health policies. We also examine how the seasonality of reported smallpox mortality changed from the 17th to 20th centuries in London.

Epidemiologic and Clinical Features of Mpox in Adults Aged >50 Years - United States, May 2022-May 2023.

During May 2022-May 2023, approximately 30,000 mpox cases were reported in the United States, predominantly among young adult men. Persons aged >50 years might experience more severe mpox disease because of a higher prevalence of comorbidities. Conversely, they could have residual protection from childhood smallpox vaccination against monkeypox virus infection and severe mpox, as has been suggested by investigation of some previous mpox outbreaks. To examine the characteristics of mpox cases among adults aged >50 years, analysts compared mpox epidemiology and clinical outcomes among all adults aged ≥18 years, by age group. Further, outcomes were compared among adults aged >50 years by JYNNEOS vaccination status. During May 10, 2022-May 17, 2023, among 29,984 adults with probable or confirmed mpox reported to CDC, 2,909 (9.7%) were aged >50 years, 96.3% of whom were cisgender men. Compared with adults aged 18-50 years, adults aged >50 years had higher prevalences of immunocompromising conditions (p<0.001) and HIV infection (p<0.001). Among adults with mpox aged >50 years, 27.6% had received JYNNEOS vaccination; this group had lower prevalences of constitutional symptoms (p<0.001), pruritus (p<0.001), and hospitalization (p = 0.002) compared with those who had not received JYNNEOS vaccine. Currently recommended JYNNEOS vaccination among all adults at risk for mpox should be encouraged, irrespective of childhood smallpox vaccination status.

[Mpox, 40 years after smallpox eradication]. / Mpox, 40 ans après l'éradication de la variole humaine.

In 2022, mpox - a neglected tropical zoonosis - emerged to the world stage. From 1980, the disease was periodically noted, with increasing frequency, in endemic regions of Africa. In 2017, a large outbreak in Nigeria marks a turning point in the evolution of mpox and seems to be at the origin of the 2022 pandemic. The factors for mpox emergence are complex and include loss of cross-protection conferred by smallpox vaccination, increased exposure to the animal reservoir, and increased human-to-human transmission due to behavioral factors. While the current epidemic seems under control, an evolution towards a more transmissible or more virulent virus is not excluded. The 2022 pandemic is an opportunity to initiate and strengthen mpox surveillance, prevention and care management among all affected populations.

En 2022, le mpox ­ une zoonose tropicale négligée ­ a émergé sur la scène mondiale. Depuis 1980, la maladie a été notifiée avec une fréquence croissante dans les régions endémiques d'Afrique. En 2017, une large épidémie au Nigeria marque un tournant dans l'évolution du mpox et semble à l'origine de la pandémie 2022. Les facteurs d'émergence du mpox sont complexes et incluent la perte de la protection croisée conférée par la vaccination antivariolique, une exposition accrue au réservoir animal et une augmentation de la transmission interhumaine due à des facteurs comportementaux. Alors que l'épidémie actuelle semble sous contrôle, une évolution vers un virus plus transmissible ou plus virulent n'est pas exclue. La pandémie 2022 est une opportunité pour initier et renforcer la surveillance, la prévention et la prise en charge clinique du mpox auprès de toutes les populations affectées.

Monkeypox outbreak in Spain: clinical and epidemiological findings in a prospective cross-sectional study of 185 cases.

BACKGROUND: Since May 2022, a new outbreak of monkeypox has been reported in several countries, including Spain. The clinical and epidemiological characteristics of the cases in this outbreak may differ from those in earlier reports. OBJECTIVES: To document the clinical and epidemiological characteristics of cases of monkeypox in the current outbreak. METHODS: We conducted a prospective cross-sectional study in multiple medical facilities in Spain to describe the cases of monkeypox in the 2022 outbreak. RESULTS: In total, 185 patients were included. Most cases started with primarily localized homogeneous papules, not pustules, in the probable area of inoculation, which could be cutaneous or mucous, including single lesions. Generalized small pustules appeared later in some of them. Heterogeneous lesions occurred during this generalized phase. All patients had systemic symptoms. Less common lesions included mucosal ulcers (including pharyngeal ulcers and proctitis) and monkeypox whitlows. Four patients were hospitalized, none died. Smallpox vaccination and well-controlled HIV disease were not associated with markers of severity. Contact during sex is the most likely mechanism of transmission. In this outbreak, cases have been described in men who have sex with men and are strongly associated with high-risk sexual behaviours. Seventy-six per cent of the patients had other sexually transmitted diseases upon screening. CONCLUSIONS: The clinical findings in this outbreak differ from previous findings and highly suggest contact transmission and initiation at the entry site. The characterization of the epidemiology of this outbreak has implications for control. What is already known about this topic? Monkeypox eruption is described as consisting of pustules. The roles of HIV and previous smallpox vaccination in the prognosis are unknown. The transmission route was initially described as respiratory droplets and was later suggested to be via sexual contact. What does this study add? Initial lesions at the probable inoculation area were homogeneous and papular (pseudopustules). Generalized small pustules appeared later in some of them. Heterogeneous lesions occurred during this generalized phase. All patients had systemic symptoms. Less common signs included mucosal ulcers (including pharyngeal ulcers and proctitis) and monkeypox whitlows. Well-controlled HIV and previous smallpox vaccination were not associated with severity. No patient died. The data support the hypothesis of transmission via contact during sex. Although this might change, the outbreak is currently limited mostly to men who have sex with men, with high-risk factors for sexually transmitted diseases.

Monkeypox: A New Threat?

The global vaccination programme against smallpox led to its successful eradication and averted millions of deaths. Monkeypox virus (MPXV) is a close relative of the Variola (smallpox) virus. Due to antigenic similarity, smallpox vaccines cross-protect against MPXV. However, over 70% of people living today were never vaccinated against smallpox. Symptoms of monkeypox (MPX) include fever, head- and muscle ache, lymphadenopathy and a characteristic rash that develops into papules, vesicles and pustules which eventually scab over and heal. MPX is less often fatal (case fatality rates range from <1% to up to 11%) than smallpox (up to 30%). MPXV is endemic in sub-Saharan Africa, infecting wild animals and causing zoonotic outbreaks. Exotic animal trade and international travel, combined with the increasing susceptibility of the human population due to halted vaccination, facilitated the spread of MPXV to new areas. The ongoing outbreak, with >10,000 cases in >50 countries between May and July 2022, shows that MPXV can significantly spread between people and may thus become a serious threat to public health with global consequences. Here, we summarize the current knowledge about this re-emerging virus, discuss available strategies to limit its spread and pathogenicity and evaluate its risk to the human population.

[Vaccination, a public health tool]. / La vaccination, un outil de santé publique.

Vaccination remains a major public health tool, the only one that has enabled the eradication of an infectious disease, smallpox. In this fight, biotechnological innovations point to considerable progress in the development of new vaccines. However, whatever technical progress is made, the impact of a vaccination program will depend on its performance and on the support of the population.

The Smallpox Epidemics in America in the 1700s and the Role of the Surgeons: Lessons to be Learned During the Global Outbreak of COVID-19.

Today's COVID-19 pandemic offers many similarities with previous pandemics hitting our country. In particular, the smallpox epidemics during the 1700s threatened the lives of multitudes and created panic and fear in the society, similar to the situation caused by the coronavirus. Remedies that were instituted, especially inoculations, were met with opposition and even violence when first introduced. The newspapers were filled with headlines reflecting the disputes. There was a "six feet rule" during the smallpox epidemics, although it had a different meaning than today. Politicians and other leaders of the society were engaged in the war against the infection. Boston became involved in the fight against the smallpox by Dr. Zabdiel Boylston's and Rev. Cotton Mather's introduction of inoculations. When George Washington realized the benefits of the procedure and ordered mass inoculations of the Continental Army, it became an important factor in winning not only the fight against smallpox but the Revolutionary War as well. Looking back at history, realizing that we have survived previous outbreaks of devastating diseases, can provide hope during the current pandemic.