Vaccination Strategies for Ebola in the Democratic Republic of Congo: The WHO-Ebola Modeling Collaboration.

Objectives: Assess the effectiveness of ring vaccination in controlling an Ebola virus outbreak in the Democratic Republic of Congo.

Methods: This analysis focuses on two areas of the Democratic Republic of Congo, Beni and Butembo/Katwa, which were affected during the 2018-2020 Ebola outbreak. To simulate Ebola virus transmission, we used a spatially explicit agent-based model with households, health care facilities, and Ebola treatment units.

Poor vaccine responders mask the true trend in vaccine effectiveness against progression to severe disease.

Vaccines can reduce an individual's risk of infection and their risk of progression to severe disease given infection. The latter effect is less commonly estimated but is relevant for vaccine impact modeling and cost-effectiveness calculations. Using a motivating example from the COVID-19 literature, we note how vaccine effectiveness against progression to severe disease can appear to increase from below 0 % to over 70 % within 8 months.

Invited Commentary: Thirty-five Years of Leaky Vaccines.

Over the past 35 years, the term "leaky vaccine" has gained widespread use in both mathematical modeling and epidemiologic methods for evaluating vaccines. Here we present a short history as we recall it of how the term was coined in the context of the history of sporozoite malaria vaccines that were thought to be possibly leaky in the 1980s. We draw a contrast with the all-or-none vaccine mechanism and review a few consequences for study design and population level effects.

The TIRS trial: Enrollment procedures and baseline characterization of a pediatric cohort to quantify the epidemiologic impact of targeted indoor residual spraying on Aedes-borne viruses in Merida, Mexico.

Aedes mosquito-borne viruses (ABVs) place a substantial strain on public health resources in the Americas. Vector control of Aedes mosquitoes is an important public health strategy to decrease or prevent spread of ABVs. The ongoing Targeted Indoor Residual Spraying (TIRS) trial is an NIH-sponsored clinical trial to study the efficacy of a novel, proactive vector control technique to prevent dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) infections in the endemic city of Merida, Yucatan, Mexico.