Waning immunity

19 April 2019  Vol 364, Issue 6437

Waning immunity
By Jon Cohen
Science19 Apr 2019 : 224-227 Full Access
Vaccine protection can fade in months or last a lifetime.Understanding why could lead to more durable immune responses.
The power of vaccines depends on their ability to train the immune system to recognize microbes and then, if an infection with one of them occurs, to mount a vigorous attack. But the immunity triggered by vaccines wanes over time, and researchers have a wobbly handle on the durability of the protection offered for several diseases. New studies suggest vaccine-induced immune responses against influenza, mumps, pertussis, and yellow fever may all disappear at a faster rate than appreciated, calling into question the timing of booster shots recommended by health officials. For adults who have received all six of their diphtheria and tetanus shots as children, their protection might be so robust that they do not need the booster that’s routinely used in the United States every 10 years. A central problem is that immunologists have not systematically investigated the mechanisms behind vaccine durability. A remarkably durable vaccine against human papillomavirus that contains what’s known as a viruslike particle offers some clues of ways forward, as it spurs the immune system to make antibodies from long-lived plasma cells, which to date have been in the shadows of their superstar cousins known as memory B cells. There is also a push to better connect data from vaccine “breakthrough” infections during outbreaks and the immune response analyses being done in laboratories that study immunization.