Immunogenicity and safety of fractional doses of 17D-213 yellow fever vaccine in children (YEFE): a randomised, double-blind, non-inferiority substudy of a phase 4 trial.

Background: Current supply shortages constrain yellow fever vaccination activities, particularly outbreak response. Although fractional doses of all WHO-prequalified yellow fever vaccines have been shown to be safe and immunogenic in a randomised controlled trial in adults, they have not been evaluated in a randomised controlled trial in young children (9-59 months old). We aimed to assess the immunogenicity and safety of fractional doses compared with standard doses of the WHO-prequalified 17D-213 vaccine in young children.

Immunogenicity and safety of fractional doses of 17D-213 yellow fever vaccine in HIV-infected people in Kenya (YEFE): a randomised, double-blind, non-inferiority substudy of a phase 4 trial.

Background: Evidence indicates that fractional doses of yellow fever vaccine are safe and sufficiently immunogenic for use during yellow fever outbreaks. However, there are no data on the generalisability of this observation to populations living with HIV. Therefore, we aimed to evaluate the immunogenicity of fractional and standard doses of yellow fever vaccine in HIV-positive adults.

Humoral and cellular immune response induced by rVSVΔG-ZEBOV-GP vaccine among frontline workers during the 2013-2016 West Africa Ebola outbreak in Guinea.

Background: As part of a Phase III trial with the Ebola vaccine rVSVΔG-ZEBOV-GP in Guinea, we invited frontline workers (FLWs) to participate in a sub-study to provide additional information on the immunogenicity of the vaccine.

Methods: We conducted an open-label, non-randomized, single-arm immunogenicity evaluation of one dose of rVSVΔG-ZEBOV-GP among healthy FLWs in Guinea. FLWs who refused vaccination were offered to participate as a control group.

Evaluation of the stability of measles vaccine out of the cold chain under extended controlled temperature conditions.

Measles outbreaks occur periodically in remote and difficult to reach areas in countries such as the Democratic Republic of Congo. The possibility to keep measles vaccines at temperatures outside the cold chain for a limited period prior to administration would be an advantage for organizations such as Médecins Sans Frontières, which repeatedly respond to measles outbreaks in difficult contexts. Using stability data at 37 °C and 40 °C provided by Serum Institute of India Private Limited we applied the product release model for Extended Controlled Temperature Conditions (ECTC) to evaluate the possibility of an out of the cold chain excursion.

Factors influencing participation in an Ebola vaccine trial among front-line workers in Guinea.

Background: Alongside the clinical aspects of the immunogenicity and safety trial of an Ebola vaccine deployed among front-line workers, a qualitative study was conducted to describe motivations behind individuals' decisions to participate - or not to participate - in the study.

Methods: In July and August 2015, focus group discussions and semi-structured individual interviews were conducted in Conakry, Guinea. Individuals were eligible for the qualitative study if they met the inclusion criteria of the immunogenicity and safety study irrespective of their participation.

Safety of the rVSV ZEBOV vaccine against Ebola Zaire among frontline workers in Guinea.

Background: As part of the ring vaccination trial in Guinea, Front Line Workers were invited to participate in a sub-study to provide additional information on the immunogenicity and safety of rVSVΔG/ZEBOV-GP. Here we summarize the information on the safety follow-up.

Methods: An open-label, non-randomized, immunogenicity evaluation of one dose of rVSVΔG/ZEBOV-GP was conducted in Conakry, Guinea between March 2015 and July 2016.

Measles seroprevalence in Chiradzulu district, Malawi: Implications for evaluating vaccine coverage.

Introduction: Self-reported measles vaccination coverage is frequently used to inform vaccination strategies in resource-poor settings. However, little is known to what extent this is a reliable indicator of underlying seroprotection, information that could provide guidance ensuring the success of measles control and elimination strategies.

Methods: As part of a study exploring HIV infection and measles susceptibility, we conveniently sampled consenting HIV-uninfected patients presenting at the HIV voluntary counselling and testing centre, and HIV-infected patients presenting for regular care, in Chiradzulu district hospital, Malawi, between January and September 2012.

A cluster randomized non-inferiority field trial on the immunogenicity and safety of tetanus toxoid vaccine kept in controlled temperature chain compared to cold chain.

Background: In resource-poor settings, cold chain requirements present barriers for vaccine delivery. We evaluated the immunogenicity and safety of tetanus toxoid (TT) vaccine in "Controlled Temperature Chain" (CTC; up to 40 °C for <30 days before administration), compared to standard cold chain (SCC; 2-8 °C). Prior to the study, stability parameters of TT-CTC were shown to meet international requirements.

Vaccination in humanitarian crises: satisficing should no longer suffice.

There are more possible vaccination interventions to mitigate the adverse health consequences of populations in crises than ever before, but recent reviews suggest delivering these vaccines has been fraught with difficulty. The decision to implement vaccination interventions in crises remains, more often than not, an exercise in satisficing. The sparse credible epidemiologic and effectiveness data in populations affected by crises contributes greatly to decision-making difficulty, as do the limits of vaccine presentations, formulations and storage.

Local discrepancies in measles vaccination opportunities: results of population-based surveys in Sub-Saharan Africa.

Background: The World Health Organization recommends African children receive two doses of measles containing vaccine (MCV) through routine programs or supplemental immunization activities (SIA). Moreover, children have an additional opportunity to receive MCV through outbreak response immunization (ORI) mass campaigns in certain contexts. Here, we present the results of MCV coverage by dose estimated through surveys conducted after outbreak response in diverse settings in Sub-Saharan Africa.