The prospective outcome of the monkeypox outbreak in 2022 and characterization of monkeypox disease immunobiology

A new threat to global health re-emerged with monkeypox's advent in early 2022. As of November 10, 2022, nearly 80,000 confirmed cases had been reported worldwide, with most of them coming from places where the disease is not common. There were 53 fatalities, with 40 occurring in areas that had never before recorded monkeypox and the remaining 13 appearing in the regions that had previously reported the disease. Preliminary genetic data suggest that the 2022 monkeypox virus is part of the West African clade; the virus can be transmitted from person to person through direct interaction with lesions during sexual activity. It is still unknown if monkeypox can be transmitted via sexual contact or, more particularly, through infected body fluids. This most recent epidemic's reservoir host, or principal carrier, is still a mystery. Rodents found in Africa can be the possible intermediate host. Instead, the CDC has confirmed that there are currently no particular treatments for monkeypox virus infection in 2022; however, antivirals already in the market that are successful against smallpox may mitigate the spread of monkeypox. To protect against the disease, the JYNNEOS (Imvamune or Imvanex) smallpox vaccine can be given. The spread of monkeypox can be slowed through measures such as post-exposure immunization, contact tracing, and improved case diagnosis and isolation. Final Thoughts: The latest monkeypox epidemic is a new hazard during the COVID-19 epidemic. The prevailing condition of the monkeypox epidemic along with coinfection with COVID-19 could pose a serious condition for clinicians that could lead to the global epidemic community in the form of coinfection.

Mpox Virus in Pregnancy, the Placenta, and Newborn

CONTEXT.—

Before its eradication, the smallpox virus was a significant cause of poor obstetric outcomes, including maternal and fetal morbidity and mortality. The mpox (monkeypox) virus is now the most pathogenic member of the Orthopoxvirus genus infecting humans. The 2022 global mpox outbreak has focused attention on its potential effects during pregnancy.

OBJECTIVE.—

To understand the comparative effects of different poxvirus infections on pregnancy, including mpox virus, variola virus, vaccinia virus, and cowpox virus. The impact on the pregnant individual, fetus, and placenta will be examined, with particular attention to the occurrence of intrauterine vertical transmission and congenital infection.

DATA SOURCES.—

The data are obtained from the authors' cases and from various published sources, including early historical information and contemporary publications.

CONCLUSIONS.—

Smallpox caused maternal and perinatal death, with numerous cases reported of intrauterine transmission. In endemic African countries, mpox has also affected pregnant individuals, with up to a 75% perinatal case fatality rate. Since the start of the 2022 mpox outbreak, increasing numbers of pregnant women have been infected with the virus. A detailed description is given of the congenital mpox syndrome in a stillborn fetus, resulting from maternal-fetal transmission and placental infection, and the potential mechanisms of intrauterine infection are discussed. Other poxviruses, notably vaccinia virus and, in 1 case, cowpox virus, can also cause perinatal infection. Based on the historical evidence of poxvirus infections, mpox remains a threat to the pregnant population, and it can be expected that additional cases will occur in the future.

Monkeypox and the perinatal period: what does maternal-fetal medicine need to know?

BACKGROUND

After the global elimination of smallpox, monkeypox has become the most threatening orthopoxvirus to human health. Very few studies have been reported on pregnant women and newborns. In the case of monkeypox infection, the virus can cause serious adverse pregnancy events in women, which can lead to fetal or neonatal death.

DATA SOURCES

We made a comprehensive review after an extensive literature search in the PubMed/Medline database and websites concerning smallpox and monkeypox.

RESULTS

Two case reports reported a total of nine pregnant women, six of whom had fetal deaths. In the autopsy of a stillbirth, researchers found that the placenta was infected with monkeypox virus, but the mechanism of infection remains unclear. Smallpox vaccine should be administered to acutely exposed pregnant women and newborns. Several novel recombinant vaccinia immunogloblin (rVIG) and human-specific monoclonal antibodies are being developed for the prevention and treatment of monkeypox virus infection. After the fetus was delivered, the newborn should take a bath as soon as possible to remove the amniotic fluid and dirt from the body. The appropriate isolation protocol for the newborn should be selected according to the infection status of the mother. It is not known whether monkeypox virus is present in breast milk, and pasteurized breast milk can be given to newborns when breastfeeding is considered.

CONCLUSION

This review presents an overview of monkeypox in the perinatal period and guides the future research direction.

Monkeypox: disease epidemiology, host immunity and clinical interventions

Monkeypox virus (MPXV), which causes disease in humans, has for many years been restricted to the African continent, with only a handful of sporadic cases in other parts of the world. However, unprecedented outbreaks of monkeypox in non-endemic regions have recently taken the world by surprise. In less than 4 months, the number of detected MPXV infections has soared to more than 48,000 cases, recording a total of 13 deaths. In this Review, we discuss the clinical, epidemiological and immunological features of MPXV infections. We also highlight important research questions and new opportunities to tackle the ongoing monkeypox outbreak.

In this Review, Ng and colleagues examine the clinical, epidemiological and immunological aspects of monkeypox virus (MPXV) infections, with a focus on mechanisms of host immunity to MPXV. The authors also consider the unique epidemiological and pathological characteristics of the current non-endemic outbreak of the virus and discuss vaccines, therapeutics and outstanding research questions.

Repositioning potentials of smallpox vaccines and antiviral agents in monkeypox outbreak: A rapid review on comparative benefits and risks

Background and aims

There is a sought for vaccines and antiviral agents as countermeasures for the recent monkeypox outbreak. Here, we aimed to review and discuss the repurposing potentials of smallpox vaccines and drugs in monkeypox outbreaks based on their comparative benefits and risks. Therefore, we conducted this rapid review and discussed the repurposing potentials of smallpox vaccines and drugs in monkeypox infection.

Methods

Here, we searched Google Scholar and PubMed for relevant information and data. We found many articles that have suggested the use of smallpox vaccines and antiviral drugs in monkeypox outbreaks according to the study findings. We read the relevant articles to extract information.

Results

According to the available documents, we found two replication‐competent and one replication‐deficient vaccinia vaccines were effective against Orthopoxvirus. However, the healthcare authorities have authorized second‐generation live vaccina virus vaccines against Orthopoxvirus in many countries. Smallpox vaccine is almost 85% effective in preventing monkeypox infection as monkeypox virus, variola virus, and vaccinia virus are similar. The United States and Canada have approved a replication‐deficient third‐generation smallpox vaccine for the prevention of monkeypox infection. However, the widely used second‐generation smallpox vaccines contain a live virus and replicate it into the human cell. Therefore, there is a chance to cause virus‐induced complications among the vaccinated subjects. In those circumstances, the available Orthopoxvirus inhibitors might be a good choice for treating monkeypox infections as they showed similar efficacy in monkeypox infection in different animal model clinical trials. Also, the combined use of antiviral drugs and vaccinia immune globulin can enhance significant effectiveness in immunocompromised subjects.

Conclusion

Repurposing of these smallpox vaccines and antiviral agents might be weapons to fight monkeypox infection. Also, we recommend further investigations of smallpox vaccines and Orthopoxvirus inhibitors in a human model study to explore their exact role in human monkeypox infections.

Vaccine exposure during pregnancy among privately and publicly insured women in the United States, 2016-2018

BACKGROUND

Vaccine use during pregnancy affects maternal and infant health. Many women do not receive vaccines recommended during pregnancy; conversely, inadvertent exposure to vaccines contraindicated or not recommended during pregnancy may occur. We assessed exposure to two recommended vaccines and two vaccines not recommended during pregnancy among privately and Medicaid-insured women in the United States.

METHODS

This study includes a retrospective cohort of pregnancies in women aged 12-55 years resulting in live birth, spontaneous abortion, or stillbirth identified in the IBM® MarketScan® Commercial, Blue Health Intelligence® (BHI®) Commercial, and IBM MarketScan Multi-State Medicaid Databases from August 1, 2016, to December 31, 2018. Gestational age at vaccination was determined using a validated algorithm. We examined vaccines (1) recommended by the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices (ACIP) (tetanus, diphtheria, and acellular pertussis [Tdap]; inactivated influenza) and (2) not recommended (human papillomavirus [HPV]) or contraindicated (measles, mumps, and rubella [MMR]).

RESULTS

We identified 496,771 (MarketScan Commercial), 858,961 (BHI), and 289,573 (MarketScan Medicaid) pregnancies (approximately 75% aged 20-34 years). Across these three databases, 52.1%, 50.3%, and 31.3% of pregnancies, respectively, received Tdap, most often at a gestational age of 28 weeks, and influenza vaccination occurred in 32.1%, 30.8%, and 18.0% of pregnancies, respectively. HPV vaccination occurred in < 0.2% of pregnancies, mostly in the first trimester among women aged 12-19 years, and MMR was administered in < 0.1% of pregnancies. Use of other contraindicated vaccines per ACIP (e.g., varicella, live attenuated influenza) was rare.

CONCLUSION

Maternal vaccination with ACIP-recommended vaccines was suboptimal among privately and Medicaid-insured patients, with lower vaccination coverage among Medicaid-insured pregnancies than their privately insured counterparts. Inadvertent exposure to contraindicated vaccines during pregnancy was rare. This study evaluated only vaccinations reimbursed among insured populations and may have limited generalizability to uninsured populations.

A Scoping Review of Pregnancy, Childbirth, and the Postpartum Period in Active Duty U.S. Military Women

PURPOSE

Women in the U.S. military encounter unique challenges during the perinatal period that are driven by military requirements for mission readiness. The purpose of this scoping review was to systematically examine the extent, range, and nature of the literature on pregnancy, childbirth, and the postpartum period of active duty military women. A secondary aim was to identify leverage points for changes to improve perinatal health of servicewomen.

METHODS

We used a PRISMA-ScR protocol to guide this scoping review of research and non-research articles germane to the perinatal health of servicewomen. In the protocol, we identified the rationale, objectives, eligibility criteria, search strategy, sources of evidence, and data charting processes for the review. We used the social ecological model for military women's health framework to guide the synthesis of results.

FINDINGS

Eighty-four articles on the topics of pregnancy, childbirth, and the postpartum period of servicewomen published from 2000 to 2018 were identified. The articles were mainly research studies (n = 76), of which 49 had observational designs. Leverage points to promote workplace safety and support of pregnant women, perinatal screening, recognition of pregnancy and postpartum depression, and maintaining physical fitness during pregnancy and the postpartum period were identified in multiple levels of the social ecological model for military women's health.

CONCLUSIONS

Literature published from 2000 to 2018 is broad in scope, yet generally lacks a robust body of evidence on any one topic. Implementing strategies and military policies that are directed at the identified leverage points could enhance the health of childbearing servicewomen.

Safety of Administering Live Vaccines During Pregnancy: A Systematic Review and Meta-Analysis of Pregnancy Outcomes

Live-attenuated vaccines (LAV) are currently contraindicated during pregnancy, given uncertain safety records for the mother-infant pair. LAV might, however, play an important role to protect them against serious emerging diseases, such as Ebola and Lassa fever. For this systematic review we searched relevant databases to identify studies published up to November 2019. Controlled observational studies reporting pregnancy outcomes after maternal immunization with LAV were included. The ROBINS-I tool was used to assess risk of bias. Pooled odds ratios (OR) were obtained under a random-effects model. Of 2831 studies identified, fifteen fulfilled inclusion criteria. Smallpox, rubella, poliovirus, yellow fever and dengue vaccines were assessed in these studies. No association was found between vaccination and miscarriage (OR 0.98, 95% CI 0.87-1.10), stillbirth (OR 1.04, 95% CI 0.74-1.48), malformations (OR 1.09, 95% CI 0.98-1.21), prematurity (OR 0.99, 95% CI 0.90-1.08) or neonatal death (OR 1.06, 95% CI 0.68-1.65) overall. However, increased odds of malformations (OR 1.24; 95% CI 1.03-1.49) and miscarriage after first trimester immunization (OR 4.82; 95% CI 2.38-9.77) was found for smallpox vaccine. Thus, we did not find evidence of harm related to LAV other than smallpox with regards to pregnancy outcomes, but quality of evidence was very low. Overall risks appear to be small and have to be balanced against potential benefits for the mother-infant pair.

Vaccinating against monkeypox in the Democratic Republic of the Congo

Healthcare-associated transmission of monkeypox has been observed on multiple occasions in areas where the disease is endemic. Data collected by the US Centers for Disease Control and Prevention (CDC) from an ongoing CDC-supported program of enhanced surveillance in the Tshuapa Province of the Democratic Republic of the Congo, where the annual incidence of human monkeypox is estimated to be 3.5-5/10,000, suggests that there is approximately one healthcare worker infection for every 100 confirmed monkeypox cases. Herein, we describe a study that commenced in February 2017, the intent of which is to evaluate the effectiveness, immunogenicity, and safety of a third-generation smallpox vaccine, IMVAMUNE®, in healthcare personnel at risk of monkeypox virus (MPXV) infection. We describe procedures for documenting exposures to monkeypox virus infection in study participants, and outline lessons learned that may be of relevance for studies of other investigational medical countermeasures in hard to reach, under-resourced populations.

Risks Associated With Smallpox Vaccination in Pregnancy: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the maternal and fetal risks of smallpox vaccination during pregnancy.

DATA SOURCES

MEDLINE, Web of Science, EMBASE, Global Health, ClinicalTrials.gov, and CINHAL from inception to September 2014.

METHODS OF STUDY SELECTION

We included published articles containing primary data regarding smallpox vaccination during pregnancy that reported maternal or fetal outcomes (spontaneous abortion, congenital defect, stillbirth, preterm birth, or fetal vaccinia).

TABULATIONS, INTEGRATION, AND RESULTS

The primary search yielded 887 articles. After hand-searching, 37 articles were included: 18 articles with fetal outcome data and 19 case reports of fetal vaccinia. Outcomes of smallpox vaccination in 12,201 pregnant women were included. Smallpox vaccination was not associated with an increased risk of spontaneous abortion (pooled relative risk [RR] 1.03, confidence interval [CI] 0.76-1.41), stillbirth (pooled RR 1.03, CI 0.75-1.40), or preterm birth (pooled RR 0.84, CI 0.62-1.15). When vaccination in any trimester was considered, smallpox vaccination was not associated with an increased risk of congenital defects (pooled RR 1.25, CI 0.99-1.56); however, first-trimester exposure was associated with an increased risk of congenital defects (2.4% compared with 1.5%, pooled RR 1.34, CI 1.02-1.77). No cases of fetal vaccinia were reported in the studies examining fetal outcomes; 21 cases of fetal vaccinia were identified in the literature, of which three neonates survived.

CONCLUSION

The overall risk associated with maternal smallpox vaccination appears low. No association between smallpox vaccination and spontaneous abortion, preterm birth, or stillbirth was identified. First-trimester vaccination was associated with a small increase in congenital defects, but the effect size was small and based on limited data. Fetal vaccinia appears to be a rare consequence of maternal smallpox vaccination but is associated with a high rate of fetal loss.

Vaccines and pregnancy: past, present, and future

Vaccination during pregnancy with certain vaccines can prevent morbidity and mortality in pregnant women and their infants. However, previous recommendations often focused on the potential risks of vaccines to the fetus when used during pregnancy. In recent years, additional data have become available on the absence of increased risks for adverse events associated with vaccines when administered during pregnancy and on their benefits to mothers and infants. Currently two vaccines - (i) inactivated influenza, and (ii) tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) - are recommended for use by all pregnant women by the United States Advisory Committee on Immunization Practices. Here we review the history of vaccination during pregnancy, the current status of recommendations for vaccination during pregnancy in the USA, and the potential for future advances in this area, including key barriers that must be overcome to accommodate these advances.

Birth defects in infants born in 1998-2004 to men and women serving in the U.S. military during the 1990-1991 Gulf War era

BACKGROUND

Concerns about reproductive health persist among U.S. military members who served in the 1990-1991 Gulf War. This study explores the long-term impact of 1990-1991 Gulf War deployment on the prevalence of birth defects among infants of Gulf War veterans.

METHODS

Health care data from the Department of Defense Birth and Infant Health Registry and demographic and deployment information from the Defense Manpower Data Center were used to identify infants born between 1998 and 2004 to both male and female 1990-1991 Gulf War veterans. Multivariable logistic regression models estimated the adjusted odds of any birth defect and eight specific birth defects among infants of deployers versus non-deployers. In addition, birth defects were evaluated among infants born to 1990-1991 Gulf War veterans with deployment-specific exposures.

RESULTS

Among 178,766 infants identified for these analyses, 3.4% were diagnosed with a birth defect in the first year of life. Compared to infants of non-deployers, infants of deployers were not at increased odds of being diagnosed with a birth defect, or any of eight specific birth defects, in the first year of life. A slightly increased prevalence of birth defects was observed among infants born to men who deployed to the 1990-1991 Gulf War for 153 to 200 days compared to those who deployed for 1 to 92 days. No other deployment-specific exposures were associated with birth defects in these infants.

CONCLUSIONS

The 1990-1991 Gulf War deployers, including those with specific exposures of concern, were not found to be at increased risk for having infants with birth defects 7 to 14 years after deployment.

New adjuvanted vaccines in pregnancy: what is known about their safety?

The recent introduction of oil-in-water emulsions as adjuvants in several pandemic vaccines, such as the H1N1 vaccine, has challenged regulatory authorities to establish their safety in the general population, as well as in specific populations. Pregnant women were advised to be a target group for H1N1 vaccination owing to the risk of this group developing serious complications with this infection. However, the addition of adjuvants to the H1N1 vaccine has initiated a discussion on the safety of adjuvanted vaccines in this special population. Changes in the maternal immune system are essential for acceptance of the fetus and for development of the placenta. The potential effects on pregnancy of interfering with this uniquely adapted immune balance through the induction of proinflammatory reactions such as those induced by adjuvanted vaccines have only been studied rarely. Here, we review the available information and discuss how vaccination may interfere with pregnancy, fetal development and pregnancy outcomes.

Health outcomes among infants born to women deployed to United States military operations during pregnancy

BACKGROUND

Military professionals who deploy to combat operations may encounter hazards that could adversely affect reproductive health. Pregnant women are generally exempt from deployment to military operations; however, exposures to such environments may inadvertently occur. We investigated whether maternal deployment during pregnancy was associated with adverse health outcomes in infants.

METHODS

The United States Department of Defense Birth and Infant Health Registry identified infants born to military service women between 2002 and 2005, and defined their health outcomes at birth and in the first year of life. Multivariable modeling was applied to investigate preterm birth and birth defects among infants, based on maternal deployment experience during pregnancy.

RESULTS

Among 63,056 infants born to military women from 2002 to 2005, 22,596 were born to women with deployment experience in support of the current military operations before, during, or after their pregnancy. These included 2941 infants born to women who appeared to have been deployed some time during their first trimester of pregnancy. Compared to infants born to women who deployed at other times, or never deployed, exposed infants were not more likely to be born preterm, diagnosed with a major birth defect, or diagnosed with a malignancy.

CONCLUSIONS

In this exploratory analysis, infants born to women who inadvertently deployed to military operations during their pregnancy were not at increased risk of adverse birth or infant health outcomes. Future analyses should examine outcomes related to specific maternal exposures during deployment, and outcomes among the growing number of infants conceived after deployment.

Infections in Pregnancy

Despite advances in peripartum care, maternal morbidity and mortality associated with infections in pregnancy are increasing even in developed countries. Recently published data from the Center for Disease Control's Pregnancy Mortality Surveillance System indicates that although maternal mortality from hemorrhage, embolism, and anesthesia has declined in the United States, the proportion of maternal deaths due to infections has increased. During 1991–7 infection accounted for 13.2% of pregnancy-related deaths overall and 36.3% of abortion-related deaths. The greatest infection risk is found in blacks, older women, women without prenatal care, and women with multiple pregnancy. In the United States pregnancy rates are stable or increasing in these groups. Infection is also a major cause of morbidity and mortality for the fetus and newborn. Many perinatal infections are associated with intra-uterine growth retardation and low birthweight, or cause fetal and neonatal brain injury. Infections, particularly bacterial vaginosis and chorioamnionitis, can result in preterm delivery of live-born infants (delivery before 37 weeks gestation), or stillbirth. A multitude of immunologic, endocrinologic, metabolic, physiologic, and anatomic changes influence the likelihood and course of many infections during pregnancy. Some of these changes are intrinsic, and occur in all normal pregnancies, while others occur to varying degrees in normal and abnormal pregnancies.

Birth defects among infants born to women who received anthrax vaccine in pregnancy

In response to bioterrorism threats, anthrax vaccine has been used by the US military and considered for civilian use. Concerns exist about the potential for adverse reproductive health effects among vaccine recipients. This retrospective cohort evaluated birth defects, in relation to maternal anthrax vaccination, among all infants born to US military service women between 1998 and 2004. Department of Defense databases defined maternal vaccination and infant diagnoses; multivariable regression models described potential associations between anthrax vaccination and birth defects in liveborn infants. Among 115,169 infants born to military women during this period, 37,140 were born to women ever vaccinated against anthrax, and 3,465 were born to women vaccinated in the first trimester of pregnancy. Birth defects were slightly more common in first trimester-exposed infants (odds ratio = 1.18, 95% confidence interval: 0.997, 1.41) when compared with infants of women vaccinated outside of the first trimester, but this association was statistically significant only when alternative referent groups were used. Although the small observed association may be unlikely to represent a causal relation between vaccination in early pregnancy and birth defects, this information should be considered when making decisions about administering anthrax vaccine to pregnant women.

Evaluation of preterm births and birth defects in liveborn infants of US military women who received smallpox vaccine

BACKGROUND

Women serving in the US military have some unique occupational exposures, including exposure to vaccinations that are rarely required in civilian professions. When vaccinations are inadvertently given during pregnancy, such exposures raise special concerns. These analyses address health outcomes, particularly preterm births and birth defects, among infants who appear to have been exposed to maternal smallpox vaccination in pregnancy.

METHODS

This retrospective cohort study included 31,420 infants born to active-duty military women during 2003-2004. We used Department of Defense databases to define maternal vaccination and infant health outcomes. Multivariable regression models were developed to describe associations between maternal smallpox vaccination and preterm births and birth defects in liveborn infants.

RESULTS

There were 7,735 infants identified as born to women ever vaccinated against smallpox, and 672 infants born to women vaccinated in the first trimester of pregnancy. In multivariable modeling, maternal smallpox vaccination in pregnancy was not associated with preterm or extreme preterm delivery. Maternal smallpox vaccination in the first trimester of pregnancy was not significantly associated with overall birth defects (OR 1.40; 95% CI: 0.94, 2.07), or any of seven specific defects individually modeled.

CONCLUSIONS

Results may be reassuring that smallpox vaccine, when inadvertently administered to pregnant women, is not associated with preterm delivery or birth defects in liveborn infants.

Monitoring the safety of a smallpox vaccination program in the United States: report of the joint Smallpox Vaccine Safety Working Group of the advisory committee on immunization practices and the Armed Forces Epidemiological Board

In December 2002, the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices and the Department of Defense Armed Forces Epidemiological Board formed a joint Smallpox Vaccine Safety Working Group (SVS WG) to provide independent safety oversight for smallpox vaccination safety-monitoring systems. From January 2003 through June 2004, the SVS WG reviewed individual and aggregate safety data on postvaccination adverse events. Serious adverse events were rare because of careful education, prevaccination screening, and strict attention to vaccination-site management. Recent vaccinees safely cared for high-risk patients, adhering to recommended site care. Human immunodeficiency virus-infected individuals without severe immunosuppression had uncomplicated vaccination reactions. Epidemiological studies supported a causal relationship between myocarditis and/or pericarditis and smallpox vaccination. Data supported neutrality regarding hypothesized causal associations between vaccination and dilated cardiomyopathy or ischemic cardiac disease. The SVS WG concurs with recommendations to defer from vaccination any person with >/=3 ischemic cardiac disease risk factors.

Introduction: vaccination against smallpox in the posteradication era

The following introduction describes the context in which the national smallpox vaccination program was implemented and highlights the significance of the key policy, programmatic, or scientific challenges, observations, and lessons learned that are presented in the articles that follow within this supplement to Clinical Infectious Diseases. Although the execution of this national program posed multiple complex and varied challenges, the focus of this supplement is on vaccine-associated adverse events and vaccine safety.