Two infections claim the lives of about 200,000 infants each year. A unique vaccination method could reverse those tragic numbers.
Where someone is born still shapes their chance of surviving the first weeks of life. The world has cut childhood deaths by more than 60% over the past three decades, yet far less progress has been made for babies in their first months. Nearly half of the children who die before age 5 are lost within the first four weeks.
What is maternal immunization?
Children under a month old are especially vulnerable to infections because their immune systems are not fully developed. Vaccinating a pregnant woman can protect her and pass antibodies to her baby—maternal passive immunity—giving the newborn critical protection in the first days and months of life.
Two proven successes are tetanus and pertussis, or whooping cough. In countries with high maternal tetanus vaccination rates, infant tetanus is rarely seen. Maternal vaccination is also about 95% effective at preventing infant deaths from whooping cough. The same idea—protecting a child through care given during pregnancy—has long been used to prevent mother-to-child transmission of HIV.
Despite decades of those successes, little work has been done to develop new maternal vaccines, in part because of concern about risk to mothers and babies. One of the foundation’s early contributions was supporting experts to establish standard definitions and statistical baselines for pregnancy outcomes. Those baselines help researchers compare studies and assess vaccine safety more clearly.
Protection against inequality
New science now offers a chance to tackle two infections that claim nearly 200,000 newborns and young infants each year. Respiratory syncytial virus (RSV) spreads through droplets and can cause severe pneumonia in babies. Group B streptococcus (GBS) can lead to stillbirth, sepsis, or meningitis if it is passed to an infant during pregnancy or delivery.
The foundation supports partners developing maternal vaccine candidates for RSV and GBS at prices that mothers and babies in low- and middle-income countries can actually reach. Roughly 20 million pregnant women worldwide carry GBS, but treatment depends on where they live. In many high-income countries, women are routinely tested and given antibiotics before delivery. In lower-income countries, that protocol is often not feasible. An estimated 97% of infant deaths due to GBS occur in low- and middle-income countries.
Each RSV season, children flood hospital wards. Survival in severe cases often depends on oxygen and ventilators. Where those are missing, a manageable illness can become a death sentence. Maternal immunization protects infants before they are born.
Families helping more infants survive
One reason the world even knows the scale of these deaths is the selflessness of grieving families. In Lusaka, Zambia, researchers studying RSV in infants worked with parents who brought babies to a hospital morgue—a doorway marked “BID,” for “brought in dead.” Families gave permission for a nasal swab so scientists could learn the cause of death. About one in 10 babies tested positive for RSV. Their loss is helping prevent the same grief for families they will never meet.
We envision a world where no family has to experience that grief. Safe, effective, and affordable RSV and GBS vaccines for pregnant women would give expectant parents a stronger start for their babies—no matter where they live.
More on maternal immunization
Return to the series · One vaccination, three incredible benefits · Why GBS screening is so important