Adjuvant and vaccine approach may protect newborns

Children's Hospital Boston has developed a new approach to infectious diseases using an adjuvant with a vaccine to protect newborns whose immune systems respond poorly to most vaccines.

In an infectious disease study led by scientists from the Medical Research Council and Children’s Division of Infectious Diseases, blood samples from 120 Gambian infants injected with stimulators of Toll-like receptors were found to yield key immune responses.

The research was led by Sarah Burl and Katie Flanagan of the Medical Research Council and Ofer Levy of Children’s Division of Infectious Diseases. By using stimulators of TLRs, a family of receptors on immune cells, called agonists, the study measured production of cytokines from white blood cells.

The study found that many of the TLR agonists elicited some form of immune response, but a thiazoloquinoline compound that stimulated TLR7 and TLR8 elicited the strongest response. The compound increased production of the cytokine TNF-alpha, which is a key component of the immune response in the first month of life. This response was the only compound to elicit production of the cytokine interferon gamma in newborns.

"Currently, until an infant gets the full vaccination series, he or she is not fully protected," Levy said. "The adjuvant could be combined with any vaccine, and if things work very well, it could provide single-shot protection at birth. Our findings in The Gambia highlight the importance of international collaboration and further underscore the potential of TLR8 adjuvants as a broadly applicable platform to enhance vaccine responses. This could possibly reduce the number of immunizations needed and the antigen dose required -- both of which would be major wins for global health."

An application of the adjuvant might be able to protect newborns in resource-poor countries where an infant might have limited opportunities to be immunized. In addition, it could protect newborns in wealthier nations like the United States where standard immunization schedules leave infants under six months more vulnerable.