Maternal Strep B Vaccination Could Prevent Thousands Of Newborn Deaths And Stillbirths Each Year

Researchers have called for a global maternal immunization program for group B Streptococcus or strep B, which they believe could save millions in healthcare costs and prevent thousands of deaths worldwide. Currently, several Strep B vaccines are under development, with some getting closer to approval. Strep B infection during pregnancy can harm both the mothers and their babies. GBS infections have been linked to increased risks of stillbirth and preterm births. It can also cause sepsis and meningitis in newborns, and even lead to death or disability.

A new study published in the open access journal PLOS Medicine revealed that a global maternal Strep B vaccination program could prevent over 200,000 cases of strep B infections in pregnant women and more than 31,000 deaths, and reduce disability in children.

Benefits of Strep B vaccination during pregnancy

Simon Procter of London School of Hygiene & Tropical Medicine, United Kingdom, and his team set out to assess the impact and value of a global maternal Strep B vaccination program. They also evaluated the cost-effectiveness of such vaccines in 140 million pregnant women in 183 countries in 2020, based on the list of preferred features for a Strep B vaccine published by the WHO.

The research team predicted that women receiving at least four antenatal visits would get vaccinated against Strep B and it would prevent the infection in 80 per cent of vaccinated women. Further, they estimated the cost of Strep B vaccine to be $50 a dose in high income countries, $15 in upper-middle income and $3.50 in low- and lower-middle income countries.

As per their calculation, maternal Strep B vaccination could prevent 127,000 early-onset and 87,300 late-onset infant iGBS cases, 31,100 deaths, 17,900 cases of moderate and severe neurodevelopmental impairment, and 23,000 stillbirths.

Cost of global maternal Strep B vaccination

Additionally, the study estimated that a 1-dose Strep B vaccine program could cost $1.7 billion globally, but it would save $385 million in healthcare costs. However, the team noted that tiered pricing is needed to allow equitable access to the vaccine.

Dr. Procter added that maternal vaccination against GBS could prevent “tens of thousands of newborn deaths and stillbirths each year.”

The researchers hope their findings will encourage more investment, which is needed to bring GBS vaccines to market.

The global burden of Group B streptococcus (GBS)

It is estimated that 15 per cent of all pregnant women carry Group B streptococcus (GBS) in their vagina, without having any symptoms. The bacterium can be transmitted from mothers to their babies during pregnancy, childbirth or in the early weeks of life. According to a report released by the World Health Organization (WHO) and the London School of Hygiene & Tropical Medicine (LSHTM) in 2021, GBS infections causes over half a million preterm births, nearly 100,000 newborn deaths, 46,000 stillbirths, and significant long-term disability.

The report stressed the urgent need for the development of maternal vaccines against GBS to reduce this toll. Although several GBS vaccine candidates are in development, none is approved for use till now.

Currently, antibiotic prophylaxis is used to prevent GBS disease in newborns, if the bacterium is detected during pregnancy. The drug is administered to a pregnant woman during labour.  However, this intervention is less effective in preventing GBS associated stillbirths, preterm births, or GBS disease that occurs later after birth.