Hand, foot and mouth disease (HFMD) is a widespread pediatric disease caused primarily by human enterovirus 71 (EV-A71) and Coxsackievirus A16 (CV-A16). This study reports a systematic review of the epidemiology of HFMD in Asia. PubMed, Web of Science and Google Scholar were searched up to December 2014. Two reviewers independently assessed studies for epidemiologic and serologic information about prevalence and incidence of HFMD against predetermined inclusion/exclusion criteria. Two reviewers extracted answers for 8 specific research questions on HFMD epidemiology. The results are checked by 3 others. HFMD is found to be seasonal in temperate Asia with a summer peak and in subtropical Asia with spring and fall peaks, but not in tropical Asia; evidence of a climatic role was identified for temperate Japan. Risk factors for HFMD include hygiene, age, gender and social contacts, but most studies were underpowered to adjust rigorously for confounding variables. Both community-level and school-level transmission have been implicated, but their relative importance for HFMD is inconclusive. Epidemiologic indices are poorly understood: No supporting quantitative evidence was found for the incubation period of EV-A71; the symptomatic rate of EV-A71/Coxsackievirus A16 infection was from 10% to 71% in 4 studies; while the basic reproduction number was between 1.1 and 5.5 in 3 studies. The uncertainty in these estimates inhibits their use for further analysis. Diversity of study designs complicates attempts to identify features of HFMD epidemiology. Knowledge on HFMD remains insufficient to guide interventions such as the incorporation of an EV-A71 vaccine in pediatric vaccination schedules. Research is urgently needed to fill these gaps.

Emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern pose a challenge to the effectiveness of current vaccines. A vaccine that could prevent infection caused by known and future variants of concern as well as infection with pre-emergent sarbecoviruses (i.e., those with potential to cause disease in humans in the future) would be ideal. Here we provide data showing that potent cross-clade pan-sarbecovirus neutralizing antibodies are induced in survivors of severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) infection who have been immunized with the BNT162b2 messenger RNA (mRNA) vaccine. The antibodies are high-level and broad-spectrum, capable of neutralizing not only known variants of concern but also sarbecoviruses that have been identified in bats and pangolins and that have the potential to cause human infection. These findings show the feasibility of a pan-sarbecovirus vaccine strategy. (Funded by the Singapore National Research Foundation and National Medical Research Council.)

SUMMARY: Notified cases of dengue infections in Singapore reached historical highs in 2004 (9459 cases) and 2005 (13 817 cases) and the reason for such an increase is still to be established. We apply a mathematical model for dengue infection that takes into account the seasonal variation in incidence, characteristic of dengue fever, and which mimics the 2004–2005 epidemics in Singapore. We simulated a set of possible control strategies and confirmed the intuitive belief that killing adult mosquitoes is the most effective strategy to control an ongoing epidemic. On the other hand, the control of immature forms was very efficient in preventing the resurgence of dengue epidemics. Since the control of immature forms allows the reduction of adulticide, it seems that the best strategy is to combine both adulticide and larvicide control measures during an outbreak, followed by the maintenance of larvicide methods after the epidemic has subsided. In addition, the model showed that the mixed strategy of adulticide and larvicide methods introduced by the government seems to be very effective in reducing the number of cases in the first weeks after the start of control.

Whether influenza vaccination offers protection for the duration of an influenza season has recently been questioned following analysis of data from test-negative design (TND) case-control studies. The published literature was systematically reviewed to identify TND studies which estimated change in vaccine effectiveness (VE) with time since vaccination. Fourteen studies were identified through the literature search as meeting eligibility criteria. Meta-analyses were performed to compare VE 15-90 days after vaccination with 91-180 days. A significant decline in VE was observed for influenza subtype A/H3 (ΔVE -33, 95% CI -57; -12) and type B (ΔVE -19, 95% CI -33; -6). VE declined for influenza subtype A/H1, but this difference was not statistically significant (ΔVE -8, 95% CI -27; 21). A multivariable mixed-effects meta-regression model indicated ΔVE was associated with the proportion of study participants who were cases and the proportion of vaccinated controls (p<0.05). This could reflect biological effects such as vaccine and circulating strain mismatch or herd immunity respectively, or the reduced power of individual TND studies in the later parts of an influenza outbreak. Exploration of new influenza vaccination strategies must be a priority for influenza control, particularly in tropical countries with year-round influenza virus activity.