Conducting vaccine studies
Generating data to accelerate vaccine development and access
Clinical studies are crucial steps along the journey of developing vaccines that save children’s lives. Careful study allows PATH and our partners to ensure that new vaccines are safe and effective, and ultimately close gaps in access to lifesaving immunizations.
From early research and clinical development through regulatory approval and introduction, we usher new vaccines through meticulous evaluation. Collaborations with universities, research institutions, and vaccine manufacturers—as well as with regulatory and ethical review bodies—ensure that the highest possible international standards are applied as vaccines move from early laboratory study through several phases of clinical trials, and finally through evaluation of real-world performance.
Covering the vaccine development pipeline
PATH’s vaccine portfolio includes products at every point in the vaccine development process. In early stages, preclinical studies test vaccine candidates in the laboratory. Once preclinical safety is established, we work with partners to conduct clinical studies among informed volunteers, following rigorous rules and regulations set by the US Food and Drug Administration and/or its counterparts in other countries. The studies are conducted in phases to evaluate a product’s safety, immunogenicity (a vaccine’s ability to induce an immune response), and protective efficacy in humans.
Each trial incorporates multiple levels of oversight to ensure the safety and confidentiality of its subjects. Ethical committees and independent review boards join safety monitors and local community advisors in reviewing study design, routinely checking standards, ensuring informed consent, and monitoring data collection.
The research continues
Vaccine evaluation continues even after introduction. Through effectiveness studies, we measure lives saved and hospitalizations reduced—the vaccine’s real-world impact on the health of children and communities. Cost-effectiveness assessments provide further information to inform government decisions on immunization programming. To maximize a vaccine’s potential, we conduct optimization studies that evaluate different dosing schedules, measure duration of immunity, and investigate booster doses. Monitoring of vaccine safety (pharmacovigilance) is also an area of work, given the importance of knowing whether any unforeseen health issues arise once a vaccine is in use in a much larger population. Late-stage studies are also critical to adding to the vaccine’s evidence base and improving data for decision-making. For example, while the Chinese-manufactured Japanese encephalitis vaccine is used throughout Asia and has proved to be safe and effective, a study in Bangladesh is gathering data on the long-term protection of a single dose for children to determine if or when a booster dose may be needed.
PATH IN ACTION
Clinical studies advance first malaria vaccine
Illustrating our experience and expertise along the vaccine clinical development pathway is our partnership with GlaxoSmithKline through PATH’s Malaria Vaccine Initiative. We joined forces in 2001 to accelerate the development of the RTS,S vaccine candidate for pediatric use against malaria, a leading parasitic disease worldwide. The collaboration has overseen Phase 2 safety and immunogenicity studies in the field, a large-scale Phase 3 efficacy and safety trial that spanned seven African countries, and the initiation of a Phase 4 program to gain further information for decision-making. Following a 2015 review of Phase 3 data, European regulators adopted a positive scientific opinion of RTS,S—a first for any malaria vaccine candidate. The World Health Organization then recommended pilot introduction of RTS,S in three to five high-burden settings in sub-Saharan Africa. [Photo: PATH/Gena Morgan]