Concerned over potency differences in pertussis vaccines, LJI vaccine biologist Alessandro Sette, Dr. Biol. Sci., has compared the kinds of T cell responses elicited in individuals administered the aP versus wP vaccines.
Sette’s team chose to study healthy adults who had undergone standard vaccination protocols with either wP or aP vaccines. His team inoculated subjects with aP vaccine boosters and evaluated immune responses, looking particularly at T cells in their blood. Following the
booster, the study volunteers showed differing T cell responses and subtle shifts in B cell population, depending on whether they had received the wP or aP vaccines. Interestingly, T cells from those who had received the aP vaccine gradually
lost their ability to respond to booster vaccination, while those primed with wP responded to the boost with a pronounced activity increase, marked by emergence of a unique gene expression profile, or “immune signature.”
This LJI study supports a theory that T cells in people vaccinated as children with wP have a better functional “memory” of the pathogen than T cells from people who received the aP form. Several novel ideas have emerged from this study. One is that the potency and durability of future vaccines might be judged by evaluating an individual’s T cell gene signature. Another is that a next-generation pertussis vaccine resembling a hybrid of aP and wP immunogens might elicit both a safe and durable response.