According to Jojanneke Heidema in her doctoral thesis, elderly people have fewer defense mechanisms against respiratory syncytial virus (RS virus), while infants infected with the virus have large numbers of activated T cells in their blood.
This means that while a vaccination for the virus could protect elderly people, this could possibly cause more harm for infants. Any vaccine for infants must be extremely well researched. Heidema discovered that children with the most severe symptoms had the strongest T cell immune response in their blood. Every year, the RS virus results in thousands of infants being admitted to the hospital.
Jojanneke Heidema received her PhD from Utrecht University on December 15, 2006. The title of her thesis is, “Human RSV-specific T cells.”