Researchers at the Children's Hospital in Boston have potentially found a way to stimulate immune responses in newborns. This could reduce infant infection rates and increase the efficacy of vaccines given at birth.
During her guest lecture Dr. McShane mentioned that one advantages of vaccinating at birth is that it is doctors can vaccinate a greater number of people when they do not rely on follow-up appointments. But, as we discussed last Thursday, there are problems with vaccinating at birth. First, newborns have inherited immunity from their mothers for a few weeks or months after birth. Second, the immune responses of infants are impaired (2), which leaves them vulnerable to infection and decreases the efficacy of most vaccines. These are two of the reasons why most vaccines are administered when the baby is two months old (except for Hep B and BCG which are given at birth).
Dr. Ofer Levy 's research suggests that one of the key differences between adult and newborn immune responses is the efficacy of their Toll-like receptors, or TLR's. According to Wikipedia TLR's are receptors on the surface of white blood cells that recognize molecules derived from microbes and activate an immune response. TLR's are part of the first line of defense against infection.
It turns out that in infants, TLR's generally trigger a weak immune response with the exception of TLR8, which triggered a robust immune response in antigen-presenting cells. Stimulating TLR8 could enhance immune response in newborns, reducing infection levels and increasing efficacy of some vaccines administered at 2 months. With funding from the Bill and Melinda Gates Foundation, Levy is now testing TLR8 stimulators in human cells and in animal models.
(1) News Story about Levy's Research
(2) Review Article on Vaccination for Infants