How a Common Childhood Vaccine Helps Ward Off Cancer

Scientists now understand why a common childhood vaccine reduces the risk of leukemia.

Researchers previously knew that the vaccine against Haemophilus influenza type B, or HiB, reduces the risk of acute lymphoblastic leukemia, the most common form of childhood cancer. But now a new study published in Nature Immunology explains why this is the case.

Dr. Markus Müschen and his team on the study used a mouse model and found that recurring HiB infections, which can happen easily in children who have not been vaccinated, can cause certain enzymes to activate and push common precancerous blood cells into cancer. So, vaccines against HiB infections also protect children from this path to leukemia.

Müschen told the New York Times that the HiB vaccine, which is routinely given to children, has led to a 20% reduction in the risk for leukemia.