The FDA has awarded breakthrough status to Pfizer's vaccine against Group B Streptococcus (GBS), a significant step forward in the fight against invasive infections in newborns and young infants. This decision is based on the strength of phase 2 data from an ongoing study, although the specific data has not yet been made public. The interim analysis was compelling enough to convince the US regulator of the vaccine's potential, leading to the breakthrough designation which could accelerate its regulatory review. Previously, the vaccine had also received fast-track status.
GBS is responsible for nearly half of all life-threatening infections in newborns, with 15-25% of women carrying the bacterium, which can be transmitted to their child during pregnancy, birth, or the early months of life. Infections can lead to severe outcomes such as late-term abortions, premature delivery, stillbirth, and in newborns, sepsis, pneumonia, or meningitis, all of which carry a high risk of severe morbidity, long-term disability, or death.
Currently, the primary method of preventing GBS disease in newborn infants is antibiotic prophylaxis administered to women during labor, but this is only effective if the bacterium is detected during pregnancy. The development of a vaccine has been a long-standing goal, with Pfizer emerging as a frontrunner in this endeavor.
According to a World Health Organization (WHO) report, the global burden of GBS is significant, linked to over half a million preterm births annually and nearly 100,000 newborn deaths, as well as at least 46,000 stillbirths. The WHO has emphasized the potential impact of a GBS vaccine, stating that if such a vaccine reaches 70% of pregnant women, it could prevent more than 50,000 GBS-related deaths and over 170,000 preterm births each year. The organization aims for at least one affordable vaccine to be licensed and authorized for maternal immunization by 2026, with rollout in 10 countries by 2030.
Pfizer has expressed encouragement by the FDA's decision and is eager to engage in discussions with the FDA and other regulatory agencies to potentially reduce neonatal deaths and alleviate the global disease burden of GBS. While GSK previously worked on a GBS vaccine, discontinuing its development in 2019, Pfizer's closest competitor now appears to be Danish biotech MinervaX, which is also developing a GBS vaccine in mid-stage trials in partnership with Sanofi.
