Babies are more likely to have infections compared to adults because their immune systems are not mature enough to fight off pathogens. Besides, they may not respond well to vaccines because antibody response in their bodies is weak. One strategy to solve these issues is to target newborn dendritic cells -- antigen-presenting cells that act as messengers between the innate and the adaptive immune systems. Recently, scientists have successfully induced strong vaccine responses in newborn animals. They add adjuvants to enhance the immune response. The studies are led by David Dowling and Ofer Levy from Boston Children’s Hospital. The findings of the studies are described in two simultaneous papers: one paper appears in JCI-Insight and the other appears in JACI. Infection is the leading cause of death among babies. Successful early life vaccines would significantly reduce infant mortality. However, now only BCG, polio vaccine and hepatitis B vaccines are effective in newborns. It is imperative to develop new, better vaccines for newborns and young infants. One thing that hampers the development of early life vaccines is that babies have distinct immune responses and therefore fail to respond optimally to most vaccines. Vaccine-induced responses of babies show slow initiation, low immunogenicity, and decreased persistence. In the study, the researchers sought to elucidate the biology of the immune system and determined that adjuvant methods might help protect young babies from severe infections. An adjuvant is a substance that modifies the effect of other agents. Adding an adjuvant to a drug or vaccine product formulation can affect the drug or vaccine in a predictable way. Adjuvantation is an important way to enhance vaccine immunogenicity, but responses of human newborn leukocytes to the majority of adjuvants are functionally distinct. Now, the researchers found that an adjuvant called 3M-052 can activate newborn immune responses. The researchers tested the alum-adjuvanted pneumococcal conjugate vaccine 13 (PCV13) in newborn Rhesus monkeys. This vaccine is designed to combat infections of Streptococcus, bacteria that is the leading cause of pneumonia and otitis media. Monkeys were randomly separated into two groups: one group receiving only PCV13 while the other group receiving both PCV13 and 3M-052. Results showed that monkeys receiving both PCV13 and 3M-052 had quicker and higher production of antibody as well as larger amounts of CD4+ T cells and B cells against Streptococcus compared to monkeys receiving only PCV13. The researchers assumed that one single dose of PCV13 and 3M-052 might be able to elicit strong enough antibody response against the bacteria. By the way, antibodies such as polyclonal antibody can be offered by CusAb.