Research shows that the HPV vaccine can prevent more than 31,000 cancer cases each year in the United States, but some states report that fewer than 50% of adolescents have initiated the HPV vaccine series. “The low rates of HPV vaccination represent an enormous missed opportunity for cancer prevention,” says Stephanie Staras, MSPH, PhD. “It’s known that if clinicians make strong recommendations for the HPV vaccine, vaccination rates increase. However, clinicians have very limited time to discuss the vaccine with parents. Therefore, interventions that increase HPV vaccination without increasing clinician time are needed.”

Various interventions that are implemented before and between clinic visits have been explored to determine acceptance of the HPV vaccine, inform skeptical parents, and address specific concerns among hesitant parents. Strategies to encourage adoption of healthier behaviors include pre-clinic vaccine reminders and motivational interviewing (MI). Pre-clinic vaccine reminders can use autodialed phone calls, text-messages, or mailed postcards, but these interventions typically result in only moderate increases in HPV vaccine uptake among adolescents. MI—an approach to enhance patients’ motivation—can be effective, but it is difficult to implement, requires intensive training, and may consume more time than physicians believe they can spend during a clinical visit.

A Two-Phased, Parent-Targeted HPV Vaccine Intervention

For a study published in BMC Public Health, Dr. Staras and colleagues evaluated the acceptability and feasibility of a two-phased, parent-targeted intervention that aimed to increase HPV vaccine initiation among 11- to 12-year-olds. In the first phase, postcards or text message reminders were sent to all parents to inform them of recommended services. In text messages, the call to action was streamlined by including an interactive scheduling system. “Postcards and text messages included content aimed at increasing parents’ motivation to get the vaccine for their child,” Dr. Staras says. “The content of these interventions was developed with parent focus groups.”

In the second phase, a sample of parents who did not have their child vaccinated despite receiving reminders were invited to phone-based MI sessions with a trained psychologist. “MI phone calls provided a centralized and theory-based way for parents to discuss their concerns with a professional who was not under the same time constraints of clinicians,” says Dr. Staras. “The postcard/text message and MI interventions were both conducted under the medical authority of the clinic and with a HIPAA waiver.”

Acceptable & Feasible

At 2 months after reminders were sent, nearly all messages were deliverable, and 7% of parents receiving text messages scheduled an appointment through the study team’s interactive system. The acceptability survey response rate was 37%, and these parents were overwhelmingly positive about the personalized reminders. “The pre-appointment interventions were acceptable and feasible even without explicit parental consent,” Dr. Staras says. Of note, 82% of respondents agreed that all parents should receive reminders about the HPV vaccine (Table).

Among 20 sampled parents who received MI, 17 were reached by phone. Of these parents, seven completed MI and four had or were getting the HPV vaccine for their child, but five reported being disinterested in participating in the study. “Compliance with the principles with MI were higher for our phone calls than among clinicians trained to MI,” Dr. Staras says. Across the seven calls in which MI was performed, the interviewer was rated 100% MI adherent.

Increasing HPV Vaccination Without Increased Clinician Burden

The results suggest that interventions used in the study addressed at least some of the needs of parents, especially those who were hesitant about HPV vaccination. “Pre-appointment interventions may be one way to increase HPV vaccination without increasing the burden on clinicians,” says Dr. Staras. “Clinicians should feel empowered to use mechanisms in electronic health records or text messaging systems to recommend HPV vaccination to patients. Our study showed that these strategies were acceptable to patients.”

According to the authors, a larger study of the interventions used is warranted. “Future research should assess the effectiveness of phone-based MI in increasing HPV vaccination,” Dr. Staras says. The study team notes that more intense pre-clinic interventions like phone-based MI may reduce physician time needed to address parental HPV vaccine hesitancy.


Staras SAS, Richardson E, Merlo LJ, et al. A feasibility trial of parent HPV vaccine reminders and phone-based motivational interviewing. BMC Public Health. 2021;21:109. Available at:

Staras SA, Vadaparampil ST, Patel RP, Shenkman EA. Parent perceptions important for HPV vaccine initiation among low income adolescent girls. Vaccine. 2014;32(46):6163-6169.

Holman DM, Benard V, Roland KB, Watson M, Liddon N, Stokley S. Barriers to human papillomavirus vaccination among US adolescents: a systematic review of the literature. JAMA Pediatr. 2014;168(1):76-82.

Staras SA, Vadaparampil ST, Livingston MD, Thompson LA, Sanders AH, Shenkman EA. Increasing human papillomavirus vaccine initiation among publicly insured Florida adolescents. J Adolesc Health. 2015;56(5 Suppl):S40-S46.

Staras SAS, Vadaparampil ST, Thompson LA, et al. Postcard reminders for HPV vaccination mainly primed parents for providers’ recommendations. Prev Med Rep. 2020;20:101188.