Learn how immunizing a critical portion of a community protects most members of the community.
The struggle between invading influenza viruses and the would-be human victim begins in the nose. NIAID grantee Ann Arvin, M.D., and her colleagues at Stanford University are trying to find out just what happens there and in the rest of the respiratory tract as it reacts to viral intruders.
People are not defenseless against the flu. All-purpose barriers such as mucous membranes in the nose, along with other parts of the innate immune system, join forces with the system’s second, “adaptive” arm—which features infection-fighting proteins called antibodies—to prevent viruses from gaining a foothold in the body.
Defenses are mounted whether virus arrives borne in the spray of someone else’s sneeze or is introduced to the body by a flu vaccine. Both the familiar injected flu shot—which contains killed virus—and the newer nasal vaccine—in which live, but weakened, flu virus is squirted into the nose—give the immune system a preview of the flu virus. This preview allows the immune system to react quickly and forcefully if the real virus is later encountered.
To design the most effective vaccines possible, scientists need a clear picture of how the innate and adaptive immune system components are stimulated by different types of vaccines. In 2004, Dr. Arvin and colleagues including Harry Greenberg, M.D., also of Stanford University, began a detailed study in children and adults comparing the immune system’s response to either standard, injected flu or to nasal vaccine made from live, weakened, virus.
The researchers examined how the two vaccines influenced T-cell and B-cell immune responses, including the production of antibodies. In addition, the research team observed the activity of natural killer cells, cells that nonspecifically destroy virus-infected cells, to determine if they play a role in the body's early warning system.
“Our goal was to conduct a side-by-side comparison of the immune responses induced by these two very different vaccines, both of which work well but in different ways," says Dr. Arvin. The team published their findings in the Journal of Virology in 2006.
S Sasaki et al. Comparison of the influenza virus-specific effector and memory B-cell responses to immunization of children and adults with live attenuated or inactivated influenza virus vaccines. J Virol. DOI: 10.1128/JVI.01957-06 (2006).
Last Updated March 13, 2013
Last Reviewed March 13, 2013