Respiratory syncytial virus vaccine development
Respiratory syncytial virus (RSV) is a widespread cause of respiratory illness and hospitalizations in infants and children worldwide. Since no vaccine against the virus exists, PATH’s RSV vaccine project is working to advance the development of RSV vaccines that can be delivered using a maternal immunization approach. We are partnering with vaccine developers, universities, government agencies, and other research institutions to speed progress toward such a groundbreaking vaccine, which could help reduce RSV morbidity and mortality as well as the heavy economic burdens associated with caring for the sick.
Advancing an RSV vaccine candidate in the clinic
We are advancing the clinical development of one or more RSV fusion (F) protein vaccine candidates up to proof-of-concept in pregnant women. Specifically, we are collaborating with vaccine developer Novavax, Inc. of Rockville, Maryland, to advance the development of its RSV F protein vaccine candidate, which has undergone Phase 2 clinical evaluations in non-pregnant women of childbearing age in the United States. Results from the studies support progression to the next stage of clinical testing. The partners are advancing the vaccine candidate to ultimately be administered to pregnant women so that high levels of maternal RSV antibodies can be naturally transferred to their newborns before birth, providing protection against infection in the early infancy period when the disease burden is the highest.
Vaccine development portfolio snapshot
Research to support RSV vaccine development efforts
PATH is building on established partnerships and developing new ones to address relevant scientific and technical issues in support of RSV vaccine development for a maternal immunization strategy.
Developing tools to test RSV vaccines
Current research suggests that vaccines designed to induce antibodies that neutralize RSV could prevent infection. To improve the accuracy, reproducibility, and efficiency of measuring these essential neutralizing antibody responses, we have collaborated with the US National Institute of Allergy and Infectious Diseases (NIAID) through a team led by Dr. Barney Graham of NIAID’s Vaccine Research Center to optimize a higher throughput platform for an RSV neutralization assay (or test). The format is designed to enable scientists to uniformly and objectively assess neutralizing antibody as a measurable sign of protection. It is an important step toward providing vaccine developers with a means to test and compare RSV vaccines.
Recently, we also collaborated with both Novartis Vaccines and Diagnostics, Inc. and GlaxoSmithKline Vaccines to develop RSV preclinical models for evaluating RSV vaccine candidates for pregnant women. These studies included developing and optimizing in vivo and in vitro models designed to add to the RSV vaccine development toolbox, and will help inform maternal immunization strategies going forward.
Assessing maternal immunization as an approach to prevent RSV
Other recent research collaborations evaluated the feasibility of RSV maternal immunization strategies in the developing world. In healthy populations, transfer of maternal protective antibody to the fetus is very efficient. In populations with chronic infections such as malaria or HIV, antibody transfer may not be as efficient.
We worked with Dr. Ruth Karron at the Bloomberg School of Public Health, Johns Hopkins University; Dr. Christopher King at Case Western Reserve University; and Dr. Willie Pomat and colleagues at the Papua New Guinea Institute of Medical Research to assess how malaria present in the placenta affects the transfer of RSV-specific neutralizing antibody from mothers to infants.
With Dr. Janet Englund of Seattle Children’s Research Institute, we studied RSV disease burden as well as the transfer and protective effect of maternal-derived RSV antibody in infants in Bangladesh and Nepal.
Under an agreement with the University of Warwick, we worked with Dr. James Nokes through the Kenya Medical Research Institute to evaluate the relationship between maternal RSV-specific antibody and protection in infants. We also looked at the rate at which antibody protection declines from birth using samples collected from newborns in Kilifi, Kenya.