Fraternal Twins: The Enigmatic Role of the Immune System in Alphaherpesvirus Pathogenesis and Latency and Its Impacts on Vaccine Efficacy.

Although the establishment, maintenance and reactivation from alphaherpesvirus latency is far from fully understood, some things are now manifestly clear: Alphaherpesvirus latency occurs in neurons of the peripheral nervous system and control of the process is multifactorial and complex. This includes components of the immune system, contributions from non-neuronal cells surrounding neurons in ganglia, specialized nucleic acids and modifications to the viral DNA to name some of the most important. Efficacious vaccines have been developed to control both acute varicella and zoster, the outcome of reactivation, but despite considerable effort vaccines for acute herpes simplex virus (HSV) infection or reactivated lesions have thus far failed to materialize despite considerable effort. Given the relevance of the immune system to establish and maintain HSV latency, a vaccine designed to tailor the HSV response to maximize the activity of components most critical for controlling reactivated infection might limit the severity of recurrences and hence reduce viral transmission. In this review, we discuss the current understanding of immunological factors that contribute to HSV and VZV latency, identify differences between varicella-zoster virus (VZV) and HSV that could explain why vaccines have been valuable at controlling VZV disease but not HSV, and finish by outlining possible strategies for developing effective HSV vaccines.

Mysteries of Monozygosity: Theories and Breakthroughs/Twin Research: Rare Case of Lost Twins; Developing a National Twin Registry; Twins' Language and Gesture Delays; DNA Testing for Vanishing Twins/Media Reports: Identical Twins Discordant for COVID Vaccination; World's Oldest Identical Twins; Olympic Athlete Stand-in; Fraternal Twin Football Players.

The processes that give rise to monozygotic (MZ) twins remain elusive. This article describes various theories of MZ twinning that have been examined over the years, although they continue to be speculative. It has also been impossible to know if a singleton began life as an MZ twin; however, a critical technological breakthrough can now reveal this important birth history information with a high degree of certainty. The section that follows presents reviews of current research regarding rare twin loss, development of a twin registry, twins' communicative delays and DNA testing for vanishing twins. The article concludes with a survey of newsworthy twins, namely identical twins discordant for COVID vaccination, the world's oldest identical twins, an Olympic athletic stand-in and fraternal twin football players.

Twins Separated at Birth: Across a Country and Around the World/Twin Research: Memorial Tribute to Isaac Blickstein, MD; Infanticide and Sacrifice of Archaic-Aged Twins and Triplets; Prehistoric Twin Burials; Highlights from a Conference on Three Identical Strangers/Media Reports: An Atypical Twin Father; An Actor's Twin Brother; Twin Link to Tulsa, Oklahoma Massacre; Superfetated Twins; Twin Comedians and Script Writers; Indian Twins' Loss to COVID-19.

Every reared-apart monozygotic (MZ) twin pair offers a fresh perspective on human developmental questions. This is true regardless of whether the co-twins were raised in the same country or across the globe. The members of two pairs of separated MZ female twins have recently come to attention. In one case the twins were raised by different families in Argentina; in the other case the twins were raised by different families in Sweden and Vietnam. The perceptions and perspectives of these twins are insightful. The twin research section that follows begins with a tribute to our late esteemed colleague, Dr Isaac Blickstein (1953-2020). Research concerning the infanticide and sacrifice of Archaic-aged twins and triplets and prehistoric twin burials is reviewed next. Highlights from a conference focused on the 2018 film Three Identical Strangers are also included in this portion. The final section of this article includes media reports of an atypical twin father, an actor's twin brother, a twin link to the 1921 Tulsa, Oklahoma massacre, the birth of superfetated twins, twin comedians and script writers and Indian twins' tragic loss to COVID-19.

Self-Reported Symptoms of COVID-19, Including Symptoms Most Predictive of SARS-CoV-2 Infection, Are Heritable.

Susceptibility to infection such as SARS-CoV-2 may be influenced by host genotype. TwinsUK volunteers (n = 3261) completing the C-19 COVID-19 symptom tracker app allowed classical twin studies of COVID-19 symptoms, including predicted COVID-19, a symptom-based algorithm to predict true infection, derived from app users tested for SARS-CoV-2. We found heritability of 49% (32-64%) for delirium; 34% (20-47%) for diarrhea; 31% (8-52%) for fatigue; 19% (0-38%) for anosmia; 46% (31-60%) for skipped meals and 31% (11-48%) for predicted COVID-19. Heritability estimates were not affected by cohabiting or by social deprivation. The results suggest the importance of host genetics in the risk of clinical manifestations of COVID-19 and provide grounds for planning genome-wide association studies to establish specific genes involved in viral infectivity and the host immune response.

Vertical transmission of SARS-CoV-2 infection and preterm birth.

Viral infections are common complications of pregnancy, with a wide range of obstetric and neonatal sequelae. Currently, there are limited data on whether SARS-CoV-2 is vertically transmitted in pregnant women tested positive for the virus. Here we describe a case of a known SARS-CoV-2-positive woman giving preterm birth to two fetuses with SARS-CoV-2 positive testing in placental tissue and amniotic fluid. The placental histological examinations showed chronic intervillositis and extensive intervillous fibrin depositions with ischemic necrosis of the surrounding villi.