Varicella-zoster virus infection: natural history, clinical manifestations, immunity and current and future vaccination strategies.

Varicella-zoster virus (VZV) is the etiologic agent of varicella (chicken pox), a childhood exanthematic disease that develops as a result of primary infection, and zoster (shingles), caused by reactivation of the virus persisting in a latent form in the dorsal sensory ganglia. Although varicella is generally a mild self-limiting illness, in immunocompromised subjects and adults it can have a serious clinical course that can lead to permanent damage of the central nervous system. In these and in most zoster cases, treatment with anti-herpetic drugs and/or immunotherapy is necessary. Because it is highly contagious, varicella is one of the most common exanthematic diseases. It is preventable by vaccination with an attenuated vaccine administered around the first year of age, and with a boost vaccination in school age. This article briefly describes the natural history and pathophysiology of VZV infection and its current epidemiology and provides an overview of current and future vaccine options to protect against varicella and/or zoster.

Replication, safety and immunogenicity of the vectored Ebola vaccine rVSV-ΔG-ZEBOV-GP in a sub-Saharan African paediatric population: A randomised controlled, open-label trial in children aged 1-12 years living in Lambaréné, Gabon.

BACKGROUND: Unlike adults, children experienced stronger and longer vector replication in plasma and shedding in saliva following rVSVΔG-ZEBOV-GP vaccination. The resulting risks of immunosuppression or immune hyperactivation leading to increased Adverse Events (AEs) and altered antibody responses are concerns that have been addressed in the present manuscript. METHODS: Children aged 1-12 years living in Gabon received either rVSVΔG-ZEBOV-GP (ERVEBO®) vaccine or the varicella-zoster virus (VZV) vaccine (VZV). The concentration of rVSVΔG vector in blood and saliva, the occurrence of AEs up to day 28; the anti-rVSVΔG-ZEBOV-GP and anti-VZV IgG antibody titres, neutralising and avidity functions of anti-rVSVΔG-ZEBOV-GP by day 365; were assessed in serum. (PACTR202005733552021) FINDINGS: In the rVSVΔG-ZEBOV-GP group, 70% and 7% of children had >0 copies/ml of rVSVΔG respectively in plasma by day 3 and in saliva by day 14 after vaccination, with no detection on day 28. Significantly higher but transient AEs occurred in the rVSVΔG-ZEBOV-GP group. Both vaccines induced seroconversion on day 28 and sustainable IgG antibody titres by day 365. Avidity and neutralisation functions of the anti-rVSVΔG-ZEBOV-GP antibodies peaked at day 28 and were maintained by day 365. INTERPRETATION: The replication and shedding do not affect the favourable risk-benefit balance of the rVSVΔG-ZEBOV-GP in children.

Investigation of the safety of live attenuated varicella-zoster virus vaccination in patients with relapse-remitting multiple sclerosis treated with natalizumab: A case series and review of the literature.

INTRODUCTION: It is generally recommended to avoid live attenuated vaccines in patients treated with high efficacy disease-modifying treatment (DMT). However, a delay in starting DMT in highly active or aggressive multiple sclerosis (MS) might lead to a significant disability. OBJECTIVE: We aimed to report a case series of 16 highly active RRMS patients who received the live-attenuated varicella-zoster virus (VZV) vaccine during treatment with natalizumab. METHODS: This retrospective case series was conducted between September 2015 and February 2022 at the MS Research Center of Sina and Qaem hospital, Tehran, Mashhad, Iran, to identify the outcome of highly active MS patients who received the live-attenuated VZV vaccine on natalizumab. RESULTS: Two males and 14 females were included in this study, with a mean age of 25.5 ± 8.4-year-old. 10 patients were naïve cases of highly active MS, and six were escalated to natalizumab. The patients received two doses of live attenuated VZV vaccine after a mean of 6.72 cycles of natalizumab treatment. Except for the one who experienced mild chickenpox infection, no serious adverse event or disease activity was evident after vaccination. CONCLUSION: While our data do not confirm the safety of the live attenuated VZV vaccine in natalizumab recipients, it highlights the importance of case-by-case decision-making in MS management based on the risk-benefit assessment.

Varicella-Zoster Virus Myocarditis: Early Clinical Diagnosis and Outcome.

Varicella-zoster virus (VZV) is a viral infection that causes chickenpox and shingles. Although it is usually self-limiting, it can lead to severe complications, especially in pediatric and immunocompromised patients. VZV was first discovered as a cause of myocarditis in 1953. In this review article, we aim to investigate the early clinical diagnosis of myocarditis in VZV infections and the efficacy of the VZV vaccine in preventing myocarditis. The literature search was done using PubMed, Google Scholar, and Sci-Hub databases. A high VZV mortality rate was noted among adults, infants, and immunocompromised patients. The early diagnosis and treatment of VZV myocarditis can reduce mortality.

Knowledge About the Herpes Zoster (HZ) Vaccine and Its Acceptance Among the Population in Al-Ahsa City in the Kingdom of Saudi Arabia.

Introduction Herpes zoster (HZ), caused by the varicella-zoster virus (VZV), poses a public health concern in Saudi Arabia, with an increasing number of cases reported in recent years. This study aimed to assess the knowledge and acceptance of the herpes zoster vaccine among Saudi Arabian citizens in Al-Ahsa. Methodology A descriptive cross-sectional study was conducted using online surveys administered via social media platforms. The study was conducted in Al-Ahsa, a city located in the Eastern Province of Saudi Arabia. Al-Ahsa serves as a representative urban area within Saudi Arabia. Result The study found a high level of awareness and knowledge about the vaccine, with 78.2% of the participants having heard of herpes zoster. The majority considered the vaccine effective (89%) and believed it was available in Saudi Arabia (87%). However, the vaccination rate was only 8%. The study revealed varied opinions on the target population for vaccination, with 39.7% favoring immunocompromised patients and 38.1% choosing individuals above 50 years. The reasons for not being vaccinated included a lack of information (38.3%) and the belief of being in good health (37.3%). Conclusion The findings suggest a need for targeted educational campaigns to address misconceptions and promote vaccination, particularly among healthcare providers and the recommended target populations. Future research should explore barriers to vaccination to inform tailored interventions.