Clinician researchers in China have developed a vaccine that
acts simultaneously against HIV-1 and M. tuberculosis (Mtb). An
estimated 14 million people worldwide are coinfected with the
two pathogens. The research is published in the May 2012 issue
of Clinical and Vaccine Immunology. The vaccine is composed of
antigens from both pathogens. The team, led by Sidong Xiong of
Fudan University, Shanghai, incorporated four Mtb epitopes (the
part of an antigen that is recognized by the immune system) into
a backbone composed of HIV-1 p24 protein, a protein that is
known to produce protective immunity against HIV-1. The logic of
this construction: many epitopes are short peptides, with poor
immunogenicity unless they are introduced into a carrier
protein—which in this case was the p24 protein. The vaccine
induced cellular immune responses to both pathogens, in which
immune system cells including macrophages search out and destroy
pathogens; and humoral immune response against HIV-1, in which
the immune system produc