Widespread use of varicella vaccine does not reduce immunity to zoster of others

Lifetime risk of herpes zoster in the population of Beijing, China

Objectives

We aimed to estimate the current and future lifetime risks (LTR) of herpes zoster (HZ) and postherpetic neuralgia (PHN), as well as their respective number of annual incident cases in Beijing, China, if individuals were not vaccinated against HZ.

Study design

Mathematical model built in Microsoft Excel, de novo.

Methods

A hypothetical cohort of 1,000 people was simulated from age 0-100 or until death to generate LTRs of HZ/PHN in Beijing, China. LTR was defined as the risk of developing HZ/PHN at least once in the person's lifetime. The current number of annual incident HZ/PHN cases were also calculated by multiplying up-to-date population data and the annual age-specific incidence of HZ/PHN. For both LTR and annual incident cases, current estimates were projected into the year 2035 to investigate the impact of an aging population. Scenario and deterministic sensitivity analyses (DSA) were conducted to validate the model outcomes.

Results

In Beijing, the current and future LTRs of HZ (PHN) were 32.4% (2.8%) and 34.8% (3.3%), respectively. The current and future annual incident cases of HZ (PHN) of individuals aged ≥50 years were 68,394 (7,801) cases among 7.04 million individuals and 88,676 (9,649) cases among 9.08 million individuals, respectively. The scenario analyses demonstrated that modelled results were likely to underestimate the LTR of HZ. Results were robust under the DSA.

Conclusions

Given an aging population, HZ poses a significant, growing burden on individuals, the society, and healthcare system of China, highlighting the need for preventative measures such as vaccination.

Monkeypox: An emerging zoonotic pathogen

Monkeypox virus (MPXV), which belongs to the orthopoxvirus genus, causes zoonotic viral disease. This review discusses the biology, epidemiology, and evolution of MPXV infection, particularly cellular, human, and viral factors, virus transmission dynamics, infection, and persistence in nature. This review also describes the role of recombination, gene loss, and gene gain in MPXV evol-vement and the role of signal transduction in MPXV infection and provides an overview of the current access to therapeutic options for the treatment and prevention of MPXV. Finally, this review highlighted gaps in knowledge and proposed future research endeavors to address the unresolved questions.

Silent Reactivation of Varicella Zoster Virus in Pregnancy: Implications for Maintenance of Immunity to Varicella

We encountered two cases of varicella occurring in newborn infants. Because the time between birth and the onset of the illness was much shorter than the varicella incubation period, the cases suggested that the infection was maternally acquired, despite the fact that neither mother experienced clinical zoster. Thus, we tested the hypothesis that VZV frequently reactivates asymptomatically in late pregnancy. The appearance of DNA-encoding VZV genes in saliva was used as an indicator of reactivation. Saliva was collected from 5 women in the first and 14 women in the third trimesters of pregnancy and analyzed at two different sites, at one using nested PCR and at the other using quantitative PCR (qPCR). No VZV DNA was detected at either site in the saliva of women during the first trimester; however, VZV DNA was detected in the majority of samples of saliva (11/12 examined by nested PCR; 7/10 examined by qPCR) during the third trimester. These observations suggest that VZV reactivation occurs commonly during the third trimester of pregnancy. It is possible that this phenomenon, which remains in most patients below the clinical threshold, provides an endogenous boost to immunity and, thus, is beneficial.