Cases of pertussis (whooping cough) have increased dramatically over the past five years, putting infants at risk of serious illness or death. Most infants are infected by a caregiver who has not received a Tdap (tetanus, diphtheria, and pertussis) booster, so caregiver immunization is particularly important. However, many caregivers go unvaccinated, and new strategies are needed to convince those living with infants to get the Tdap booster. To address this care gap, a team of researchers lead by Alison Buttenheim PhD, MBA, an Assistant Professor of Nursing and an Assistant Professor of Health Policy at the University of Pennsylvania School of Nursing, evaluated the feasibility and impact of different interventions aimed at increasing the number of vaccinated caregivers. The results of their study are set for publication in the February issue of Vaccine, but are currently available online here.

The team conducted a randomized controlled feasibility trial among adults attending newborn well-child visits at an urban Philadelphia pediatric primary care clinic who were not previously vaccinated with Tdap. Participants were randomized to one of four conditions: (a voucher for $5 off a Tdap vaccine at a nearby retail pharmacy versus a voucher for a free vaccine) and (watching a one minute public service announcement

(PSA) about Tdap vaccination featuring Jennifer Lopez versus no PSA). Tdap vaccination was assessed by tracking voucher redemption at the retail pharmacy and following up with participants by phone. Ninety-five adult caregivers of 74 infants were enrolled in the study. Fifty-four percent were the child's father; 33 percent the mother; 13 percent a grandparent or other caregiver. Thirty-five percent of the caregivers were on Medicaid; 34 percent had private insurance; and 32 percent were uninsured.

Of the 95 caregivers in the study, only one redeemed the retail pharmacy voucher. "This finding was surprising and disappointing given that the full cost vouchers eliminated any financial barriers to vaccination. Our subsequent follow up interviews suggested that, even with the voucher, there were other significant barriers that prevented vaccination," said Buttenheim. These barriers include delaying the planned vaccination, a perception that pharmacy locations were inconvenient and false beliefs about the risk and severity of whooping cough.

The investigators concluded that despite leveraging existing vaccination services at retail pharmacies, vaccine vouchers and celebrity video promotion delivered during a newborn visit were not an effective strategy for increasing Tdap vaccination. "We continue to look for alternate approaches that prioritize convenience and provide an immediate opportunity to vaccinate when the motivation to do so is high," added Buttenheim.