During vaccination, the immune system is purposefully exposed to weakened, inactivated, or a component of pathogens so that the body can recognize their molecular structures in the future and mount a ...

However, details of the intervening steps, as researchers have learned in the past 65 years, are quite complex — certain cells carry the flu antigen to the immune system, specific immune cells respond ...

At the surface, the immune response to a flu virus is simple. Some cells recognize the pathogen and send a signal to the immune system, and immune cells produce a potentially lifesaving antibody ...