Professor Shabir Madhi began his career at a turning point in South Africa’s history. In the wake of apartheid, the country launched comprehensive immunization campaigns aimed at reaching all children—many for the first time. Dr. Madhi joined the effort as a young public health researcher, tasked with studying how a new pneumococcal conjugate vaccine (PCV) might reduce child deaths across Africa.
“Our findings were just phenomenal,” he says. At the time, pneumonia was killing nearly 850,000 children under five each year. But with the vaccine, the most severe forms were reduced by 90%.
Vaccines that changed the story for children
Since then, Dr. Madhi has been at the center of a global public health revolution. Vaccines—called “the single greatest contribution to improved infant survival over the past 500 years”—have helped cut child mortality in half since 2000 and saved more than 150 million lives since 1974. “I’ve been fortunate that my career has seen the introduction of many life-saving vaccines,” he says.
One of those vaccines targeted rotavirus, a leading cause of severe diarrhea in children that can be fatal without treatment. “We used to have whole wards reserved for children admitted for rotavirus,” Dr. Madhi recalls. “Within a year of introducing the vaccine, those wards were shut down across the country because they were empty. Rotavirus almost disappeared.”
A new frontier: maternal immunization protecting babies before birth
Today, as director of the Vaccines and Infectious Disease Analytics unit at the University of the Witwatersrand, Dr. Madhi is focused on a new frontier in immunization: maternal vaccines. These vaccines—administered during pregnancy—can protect newborns during their most vulnerable window of life: the first three to six months.
He first saw the promise of maternal immunization as a young resident. At the time, babies suffering from neonatal tetanus were admitted to his hospital every week—and more than 90% of them died. But once pregnant women started receiving the tetanus vaccine, deaths fell dramatically: from 500,000 a year to fewer than 50,000 today.
The impact doesn’t end there. Dr. Madhi found that babies born to mothers who received a pneumonia vaccine were 40% less likely to be hospitalized with the disease. “It was a massive finding,” he says. “When you add up the number of babies benefiting, it runs into hundreds of thousands across the world.”
Scaling protection against RSV and GBS
Now, Dr. Madhi is focused on developing maternal vaccines for two diseases that remain especially deadly for infants: respiratory syncytial virus (RSV) and group B streptococcus (GBS). RSV is a viral infection; GBS is bacterial. Together they account for nearly 200,000 infant deaths each year.
New maternal vaccines could prevent many of those deaths. In fact, World Health Organization prequalified the first-ever maternal vaccine for RSV in March 2025—a major milestone.
Dr. Madhi is committed to ensuring these tools are not only effective, but widely accessible. “What really inspires me and keeps me going,” he says, is knowing the impact vaccines have had—and the potential they still have. It’s knowing we can make a difference.”
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