Vouchers to Promote Tdap Vaccination

The incidence of pertussis, a highly contagious respiratory illness, has more than tripled
in the past five years, and is on track this year to be the most severe in over a half
century. Pertussis is particularly dangerous, and commonly fatal, for young infants who have
not completed the primary vaccination series. To protect infants, pregnant women and adult
caregivers should receive Tdap vaccination, but coverage is estimated at only 10% for adult
caregivers in close contact with infants.

The objective of this study is to conduct a small-scale randomized controlled trial of an
intervention to increase Tdap immunization rates among infant caregivers. The intervention
is delivered at the newborn primary care visit and consists of two components: (1) Tdap
vaccine vouchers redeemable at neighborhood retail pharmacies and (2) video-based education.
The vouchers improve vaccine supply by reducing cost and improving accessibility of the
vaccine, while the education component increases demand for the vaccine by making salient
the dangers of pertussis and the importance adult vaccination to "cocoon" vulnerable
infants. We will evaluate the feasibility and acceptability of each component or both
compared to none and assess the impact on the vaccination of parents/caregivers of newborn
infants.

Recruitment for this pilot study will take place at a pediatric primary care practice site
affiliated with a large children's hospital in Philadelphia, Pennsylvania (PA). The
practice schedules approximately 135 newborn visits per month, typically at 2-14 days of
life. Participants will redeem Tdap vaccine vouchers at 2 local Rite Aid pharmacies which
are the closest Rite Aid locations to the clinic site. The pharmacy accepts all major
insurance plans, although most plans (including Medicaid) do not cover Tdap vaccine
delivered in pharmacies.

All caregivers ≥ 18 years old who accompany an infant to a newborn visit will be approached
by the study coordinator and details of the study will be explained. Caregivers will be
asked to participate in the study and if interested, informed consent will be obtained
before any study related procedures are performed. Potential subjects will then be screened
using the protocol inclusion and exclusion criteria. The research assistant will utilize a
data collection form to collect demographic data. After completion of the data collection
form, participants will view an educational video if randomized to the education arm. After
viewing the educational video, or after completion of data collection form for those who
were not randomized to video, participants will receive an envelope containing the Tdap and
baby care item voucher or gift card.

Unvaccinated caregivers will receive an envelope containing 2 vouchers or a voucher and a
gift card. The vouchers are: one for Tdap vaccination and one for a baby care item.
Vouchers will be redeemable only at the two participating nearby Rite Aid pharmacies, will
have no monetary value, and cannot be redeemed for any items other than the specified
vaccine/baby care product.The gift card can be redeemed at any Rite Aid pharmacy.All
envelopes will also contain the Center for Disease Control and Prevention (CDC) Vaccine
Information Sheet (V.I.S) for the Tdap vaccine. Participants will be randomized to receive
either: (1) a voucher for the full price of a Tdap vaccine ($63.99) + a baby care product
voucher/or gift card, or (2) a voucher for $5 off a Tdap vaccine + a baby care product
voucher/or gift card. The baby care product voucher / gift card will allow us to assess the
proportion of respondents who make a trip to one of the pharmacies following the primary
care visit and may also increase the probability that the study participants will visit one
of the designated retail pharmacies. The full cost voucher removes any cost barriers
related to the Tdap vaccine. The $5 voucher allows us to assess the effect of increased
awareness, convenience, and accessibility on vaccine uptake, but without a significant price
change. If two unvaccinated caregivers accompany an infant and both choose to enroll in the
study, they may receive discordant Tdap voucher amounts; however, both will receive baby
care product vouchers / gift cards.

Randomization to each arm will occur through block randomization of study numbers that will
take place prior to recruitment. The research assistants will show the video and will
therefore not be blinded to educational arm. However, research assistants who enroll
participants will be blinded to voucher arm as envelopes will be sealed. Research staff
will enter the study number on the data collection form but only the principal investigator
and study coordinator will have access to the master file indicating allocation to
intervention group.

Voucher redemption is voluntary; data regarding vaccination redemption will be collected by
Rite Aid pharmacies. Participants who choose to redeem Tdap vaccine vouchers can do so, at
their convenience, at 2 local Rite Aid pharmacies. At the pharmacy, the caregiver must
complete a screening form before receiving Tdap. Vouchers are serialized with a barcode
which is swiped at the time of redemption Baby care item vouchers will be like a coupon and
can be redeemed by a cashier at the pharmacy.

Project staff will perform phone follow-up interviews with participants one month after they
were enrolled in the study to ascertain vaccination status and to solicit feedback on the
intervention and barriers to vaccination.

Baseline characteristics will be summarized by standard descriptive summaries (e.g. means
and standard deviations for continuous variables and percentages for categorical variables).
All vouchers will have unique identification (ID) numbers. Variables such as age, gender,
insurance status, the relationship of the participant(s) to the infant, vaccination status,
and the date and time of the voucher distribution will be summarized. The research
coordinator will also record how many caregivers refuse to participate or are not approached
for enrollment. The proportion of caregivers screened that meet enrollment criteria and the
proportion meeting enrollment criteria that consent to participate will be calculated.

We will measure the proportion of participants enrolled that redeemed a study Tdap voucher.
In addition, we will assess the feasibility of voucher distribution, the completeness of
redemption data recorded at the pharmacy, and the ability to assess caregiver vaccination
status. Vaccination status will be determined by self-report at the time of enrollment and
at the time of the follow-up interview. Vaccination rates will also be measured by Tdap
voucher redemption. We will measure the redemption rate of the Tdap voucher by treatment
arm ($5 voucher vs. full-cost voucher, and video vs. no video), adjusting for
sociodemographic characteristics. We will also determine the proportion of baby care
product vouchers / gift cards redeemed by treatment arm.

Inclusion Criteria:

1. All caregivers who report that they have never received Tdap

2. Mothers who did not receive Tdap during their most recent pregnancy or since the
birth of the child, even if she received Tdap during a previous pregnancy, as Tdap is
now recommended for all pregnant women during each pregnancy.

3. Previous receipt of a tetanus containing vaccine (i.e. Td or TT), regardless of the
time interval since receipt of the tetanus-containing vaccine will be also eligible
for the study.

4. If a participant is certain they have not received Tdap within the past year but
uncertain whether he/she has ever received Tdap, we will offer enrollment and
encourage participants to obtain immunization records to confirm their status before
voucher redemption. Rite Aid will follow their screening procedures which also
includes assessing immunization status. Participants who do not know their Tdap
vaccination status will receive the voucher intervention.

Exclusion Criteria:

1. Any adult caregiver who has previously received Tdap

2. For recently-pregnant women: If a mother who received Tdap during her most recent
pregnancy (2nd trimester or 3rd trimester) or since the birth of the child. Also, if
the mother is unsure of her vaccination status and possibly received the vaccine
during this pregnancy or in the last year