Interventions to improve adolescent vaccination coverage

Improving vaccination uptake among adolescents

BACKGROUND

Adolescent vaccination has received increased attention since the Global Vaccine Action Plan's call to extend the benefits of immunisation more equitably beyond childhood. In recent years, many programmes have been launched to increase the uptake of different vaccines in adolescent populations; however, vaccination coverage among adolescents remains suboptimal. Therefore, understanding and evaluating the various interventions that can be used to improve adolescent vaccination is crucial.

OBJECTIVES

To evaluate the effects of interventions to improve vaccine uptake among adolescents.

SEARCH METHODS

In October 2018, we searched the following databases: CENTRAL, MEDLINE Ovid, Embase Ovid, and eight other databases. In addition, we searched two clinical trials platforms, electronic databases of grey literature, and reference lists of relevant articles. For related systematic reviews, we searched four databases. Furthermore, in May 2019, we performed a citation search of five other websites.

SELECTION CRITERIA

Randomised trials, non-randomised trials, controlled before-after studies, and interrupted time series studies of adolescents (girls or boys aged 10 to 19 years) eligible for World Health Organization-recommended vaccines and their parents or healthcare providers.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened records, reviewed full-text articles to identify potentially eligible studies, extracted data, and assessed risk of bias, resolving discrepancies by consensus. For each included study, we calculated risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI) where appropriate. We pooled study results using random-effects meta-analyses and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 16 studies (eight individually randomised trials, four cluster randomised trials, three non-randomised trials, and one controlled before-after study). Twelve studies were conducted in the USA, while there was one study each from: Australia, Sweden, Tanzania, and the UK. Ten studies had unclear or high risk of bias. We categorised interventions as recipient-oriented, provider-oriented, or health systems-oriented. The interventions targeted adolescent boys or girls or both (seven studies), parents (four studies), and providers (two studies). Five studies had mixed participants that included adolescents and parents, adolescents and healthcare providers, and parents and healthcare providers. The outcomes included uptake of human papillomavirus (HPV) (11 studies); hepatitis B (three studies); and tetanus-diphtheria-acellular-pertussis (Tdap), meningococcal, HPV, and influenza (three studies) vaccines among adolescents. Health education improves HPV vaccine uptake compared to usual practice (RR 1.43, 95% CI 1.16 to 1.76; I² = 0%; 3 studies, 1054 participants; high-certainty evidence). In addition, one large study provided evidence that a complex multi-component health education intervention probably results in little to no difference in hepatitis B vaccine uptake compared to simplified information leaflets on the vaccine (RR 0.98, 95% CI 0.97 to 0.99; 17,411 participants; moderate-certainty evidence). Financial incentives may improve HPV vaccine uptake compared to usual practice (RR 1.45, 95% CI 1.05 to 1.99; 1 study, 500 participants; low-certainty evidence). However, we are uncertain whether combining health education and financial incentives has an effect on hepatitis B vaccine uptake, compared to usual practice (RR 1.38, 95% CI 0.96 to 2.00; 1 study, 104 participants; very low certainty evidence). Mandatory vaccination probably leads to a large increase in hepatitis B vaccine uptake compared to usual practice (RR 3.92, 95% CI 3.65 to 4.20; 1 study, 6462 participants; moderate-certainty evidence). Provider prompts probably make little or no difference compared to usual practice, on completion of Tdap (OR 1.28, 95% CI 0.59 to 2.80; 2 studies, 3296 participants), meningococcal (OR 1.09, 95% CI 0.67 to 1.79; 2 studies, 3219 participants), HPV (OR 0.99, 95% CI 0.55 to 1.81; 2 studies, 859 participants), and influenza (OR 0.91, 95% CI 0.61 to 1.34; 2 studies, 1439 participants) vaccination schedules (moderate-certainty evidence). Provider education with performance feedback may increase the proportion of adolescents who are offered and accept HPV vaccination by clinicians, compared to usual practice. Compared to adolescents visiting non-participating clinicians (in the usual practice group), the adolescents visiting clinicians in the intervention group were more likely to receive the first dose of HPV during preventive visits (5.7 percentage points increase) and during acute visits (0.7 percentage points for the first and 5.6 percentage points for the second doses of HPV) (227 clinicians and more than 200,000 children; low-certainty evidence). A class-based school vaccination strategy probably leads to slightly higher HPV vaccine uptake than an age-based school vaccination strategy (RR 1.09, 95% CI 1.06 to 1.13; 1 study, 5537 participants; moderate-certainty evidence). A multi-component provider intervention (including an education session, repeated contacts, individualised feedback, and incentives) probably improves uptake of HPV vaccine compared to usual practice (moderate-certainty evidence). A multi-component intervention targeting providers and parents involving social marketing and health education may improve HPV vaccine uptake compared to usual practice (RR 1.41, 95% CI 1.25 to 1.59; 1 study, 25,869 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Various strategies have been evaluated to improve adolescent vaccination including health education, financial incentives, mandatory vaccination, and class-based school vaccine delivery. However, most of the evidence is of low to moderate certainty. This implies that while this research provides some indication of the likely effect of these interventions, the likelihood that the effects will be substantially different is high. Therefore, additional research is needed to further enhance adolescent immunisation strategies, especially in low- and middle-income countries where there are limited adolescent vaccination programmes. In addition, it is critical to understand the factors that influence hesitancy, acceptance, and demand for adolescent vaccination in different settings. This is the topic of an ongoing Cochrane qualitative evidence synthesis, which may help to explain why and how some interventions were more effective than others in increasing adolescent HPV vaccination coverage.

Knowledge about HPV and vaccination among young adult men and women: Results of a national survey

BACKGROUND

In addition to screening by Pap smears, vaccination against human papillomavirus (HPV) can dramatically reduce cervical cancers caused by the virus. The acceptance of HPV vaccination is directly related to HPV knowledge. This research aimed to evaluate knowledge about HPV and vaccination among men and women aged 16-25 years who use the public health system in Brazil.

METHODS

This was a cross-sectional, multicenter study of sexually active young adults recruited from 119 primary care units between 2016 and 2017. All participants answered a face-to-face standardized questionnaire.

RESULTS

Of 8581 participants, the mean percentage of correct answers about HPV and vaccination was 51.79% (95% CI 50.90-52.67), but 75.91% (95% CI 74.13-77.69) had awareness of the HPV vaccination. Women answered a higher proportion of questions correctly than men did (p = 0.0003). Lower education level was the variable that most interfered with knowledge. The best information sources for knowledge were both health professionals and the media (1.33%, 95% CI 1.03-1.70).

CONCLUSIONS

The results emphasize the importance of educational programs about HPV and vaccination among young adults, especially in socially disadvantaged populations. These findings can help to increase the vaccination rate in the country and to stimulate public health policies.

Human Papillomavirus Vaccination Coverage Among Girls Before 13 Years: A Birth Year Cohort Analysis of the National Immunization Survey-Teen, 2008-2013

Routine human papillomavirus (HPV) vaccination is recommended at 11 or 12 years by the Advisory Committee on Immunization Practices. National Immunization Survey-Teen data were analyzed to evaluate, among girls, coverage with one or more doses of HPV vaccination, missed opportunities for HPV vaccination, and potential achievable coverage before 13 years. Results were stratified by birth year cohorts. HPV vaccination coverage before 13 years (≥1 HPV dose) increased from 28.4% for girls born in 1995 to 46.8% for girls born in 2000. Among girls born during 1999-2000 who had not received HPV vaccination before 13 years (57.2%), 80.1% had at least 1 missed opportunity to receive HPV vaccination before 13 years. Opportunities to vaccinate for HPV at age 11 to 12 years are missed. Strategies are needed to decrease these missed opportunities for HPV vaccination. This can be facilitated by the administration of all vaccines recommended for adolescents at the same visit.