Tdap-HPV vaccination bundling in the USA: Trends, predictors, and implications for vaccine series completion

The Centers for Disease Control and Prevention (CDC) promotes taking a 'bundling approach' (i.e., administering Tetanus, diphtheria toxoids, and acellular pertussis [Tdap] and human papillomavirus [HPV] vaccines in the same way and on the same day) for adolescent vaccinations. Recent trends and patterns in Tdap-HPV vaccination bundling in the USA remain undocumented. In addition, the implications of bundling Tdap-HPV vaccination for HPV vaccine series completion remain unknown. To address these critical knowledge gaps, we performed a retrospective study using a nationwide sample of privately insured adolescents (Optum's de-identified Clinformatics® Data Mart Database). Tdap-HPV vaccination bundling (per 100 Tdap vaccination encounters) during 2014-2018 was estimated overall, for 50 states, and by adolescents' age, sex, and provider specialties. Survival model estimated the likelihood of series completion among 9-14-year-old adolescents. From 2014 to 2018, 560,806 adolescents received a Tdap vaccine of which 172,604 (30.8%) received the HPV vaccines on the same day. Tdap-HPV vaccination bundling (per 100 Tdap vaccinations) increased nationally, from 22.9 in 2014 to 39.1 in 2018 (Ptrend < 0.001); bundling was lowest in New York and New Jersey. The likelihood of receiving the Tdap and HPV vaccines bundled was higher for young and female adolescents. Adolescents who received their first HPV vaccine bundled with the Tdap vaccine were more likely to complete the series compared to those who received it alone (Hazards Ratio = 1.45; 1.43-1.48). HPV vaccination bundling has increased in recent years in the USA. The increased likelihood of HPV vaccine series completion provides important evidence supporting the adoption of same-day Tdap-HPV vaccine administration in clinical practice to boost HPV vaccination coverage.

Completion of the two-dose recombinant zoster vaccine series in adults 50 years and older

BACKGROUND

In 2017, a new adjuvanted recombinant zoster vaccine (RZV) was recommended for adults ≥50 years as two-dose series 2-6 months apart. We evaluated two-dose RZV completion and factors associated with completion.

METHODS

The study included Kaiser Permanente Southern California members ≥50 years who received an RZV dose during April-November 2018 and had continuous membership 12 months before to 9 months after the first RZV dose. Completion was defined as receipt of the second dose ≥4 weeks to 9 months after the first dose (allowing 3-month grace period). Characteristics including age, sex, race/ethnicity, Medicaid status, neighborhood level income and education, comorbidities, history of zoster, health care utilization before and after the first dose, receipt of influenza vaccine, vaccination month (supply shortage proxy), concomitant vaccine, medical center, and medically attended reactions, pain, or gout after the first dose were compared between completers and non-completers. Adjusted odds ratios and 95% confidence intervals for factors associated with completion were estimated by multivariable logistic regression.

RESULTS

Among 31,120 first dose recipients, 67.2% completed the series within 9 months. In adjusted analyses, higher completion was associated with White compared with Black or Hispanic race/ethnicity, higher neighborhood income and education, no chronic pulmonary disease, diabetes, or dementia, more outpatient visits and fewer emergency department visits before or after the first dose, no hospitalizations after the first dose, receipt of influenza vaccine, receipt of the first dose in June-November rather than April-May 2018, and no concomitant vaccine with the first dose. Systemic reactions or pain after the first dose was not associated with completion.

CONCLUSION

Completion of RZV series appears suboptimal in the early phase of implementation. Despite similar accessibility in a health care system, completion varied by race/ethnicity, socioeconomic status, health status, and care seeking behavior, suggesting areas to target for improvement.

Adherence to hepatitis A and hepatitis B multi-dose vaccination schedules among adults in the United Kingdom: a retrospective cohort study

BACKGROUND

Timely and complete vaccination with multi-dose schedules is of public health importance, because an incomplete vaccination series may yield suboptimal disease protection. However, data on adherence of adults to multi-dose vaccines are limited. We sought to estimate adherence to multi-dose hepatitis vaccination schedules among adults in the United Kingdom (UK).

METHODS

This retrospective cohort study was conducted using anonymized electronic health record (EHR) data from the Clinical Practice Research Datalink (CPRD). Individuals aged 19 years and older at their first identified dose of hepatitis vaccine (2009-2016) were included if they had continuous EHR data for 12 months before the first identified hepatitis A dose or for 6 months before the first identified hepatitis B or combination hepatitis A/B dose. We estimated dose and series completion for each vaccine and adherence to recommended vaccination schedules, as well as adherence within additional prespecified time periods after the first vaccine dose, with sensitivity analyses restricted to adults who had available data for up to 24 months after the first dose. Median time to series completion was estimated using Kaplan-Meier methods.

RESULTS

Mean (SD) age at initiation was 42 (16) years for hepatitis A (n = 374,881), 40 (16) years for hepatitis B (n = 71,634), and 38 (15) years for hepatitis A/B (n = 10,335). Women comprised 52 to 55% of each vaccine cohort. Overall, 42,294 adults (11%) completed the two-dose hepatitis A vaccine series within the recommended 12 months; and 15,564 (22%) and 1076 (10%) completed the three-dose hepatitis B and hepatitis A/B series, respectively, within the recommended 6 months. These percentages rose to only 23, 35, and 33%, respectively, when the follow-up periods were extended to 36 months for hepatitis A and to 30 months for hepatitis B and A/B vaccines. Median times to series completion within recommended schedules were not reached in any cohort. Sensitivity analyses supported the primary findings for the full cohorts.

CONCLUSIONS

Adherence and series completion rates for hepatitis A and B vaccines in the UK are low. Identifying, understanding, and addressing barriers to series completion for multi-dose vaccines for adults in real-world settings are needed.