Pfizer Group B strep vaccine for infants returns strong trial results

on Jul20
by | Comments Off on Pfizer Group B strep vaccine for infants returns strong trial results |

Streptococcus agalactiae bacteria, responsible for vaginal and urinary tract infections and newborn infections including meningitis and septicemia. Optical microscopy view.

Cavallini James | BSIP | Universal Images Group | Getty Images

Pfizer on Wednesday said its experimental vaccine targeting the potentially deadly bacterial disease Group B Streptococcus returned strong mid-stage clinical trial results, a promising step as the drug inches toward potential approval.

Pfizer is among several drugmakers racing to develop the world’s first shot targeting Group B strep disease, which is linked to nearly 150,000 infant deaths worldwide each year, especially in lower-income countries.

related investing news

Goldman Sachs reports mixed second-quarter results. Here's what the pros are saying

CNBC Pro

The Food and Drug Administration in September granted breakthrough therapy designation to Pfizer’s vaccine, which is intended to expedite the development and review of the shot. 

Pfizer’s single-dose shot generated antibodies that may provide infants with meaningful protection against the disease, according to the data released Wednesday from a phase two clinical trial.

The jab is administered to expectant mothers, who pass vaccine-induced antibodies to their fetuses. One of the company’s vaccines targeting respiratory syncytial virus also uses that maternal vaccination method. 

Pfizer’s encouraging phase two trial results provide hope that maternal vaccination against the disease, also known as GBS, could help prevent thousands of cases in babies. 

The results will also help the company plan its phase three clinical trials on the shot, which are typically required before the FDA approves a drug.

The Bill & Melinda Gates Foundation, which supported the phase two trial, provided an additional $100 million grant to Pfizer last year that will fund late-stage trials and help facilitate the delivery of shots to lower-income countries following a potential approval.

GBS risk

Trial results and safety

Pfizer’s trial followed 360 healthy pregnant individuals in South Africa. The mothers were randomly assigned to receive a single shot at three different dosage levels, with or without a specific adjuvant, or a placebo. 

The trial found that Pfizer’s shot generated robust antibodies against the six GBS serotypes in mothers. Those antibodies were “efficiently transferred” to infants at ratios between 0.4 and 1.3, depending on the dose. 

That means some infants received only a fraction of antibodies from their mothers, while others received higher antibody levels than even what their mothers had. 

Pfizer said those antibody transfer levels are associated with a reduced risk of GBS disease. That conclusion was based on a parallel natural history conducted in South Africa.

The safety profile for both mothers and infants appeared to be similar between the vaccine and placebo groups, according to the trial results, suggesting that the shot was generally well tolerated during the phase two trial.

Reactions among mothers following vaccination were generally mild or moderate and short in duration. Between 2% to 8% of participants who received the shot reported fever, compared with 5% in the placebo group, according to the results. 

CNBC Health & Science

Read CNBC’s latest health coverage:



Previous postStock picks for companies to benefit from the IRA: BofA Next postStocks making the biggest moves after hours: NFLX, TSLA, IBM


Los Angeles Financial times


Copyright © 2024 Los Angeles Financial times

Updates via RSS
or Email