Low uptake of shingles vaccine despite strong value proposition for older adults

A recent literature review published in Vaccine this month highlighted a puzzling disparity in preventive care for U.S. adults aged 50 and older. The recombinant zoster vaccine (RZV) offers clinical and economic benefits comparable or superior to other recommended services, yet its utilization lags far behind.

The research, conducted by Justin Gatwood, Ph.D., from GSK, in collaboration with colleagues from Cencora, analyzed real-world data from 2012 to 2022 regarding RZV in conjunction with five principal comparators: influenza, pneumococcal, tetanus-diphtheria/tetanus-diphtheria-pertussis (Td/Tdap), and hepatitis B vaccines, as well as colorectal cancer (CRC) screening. The review utilized databases such as EMBASE and Medline to investigate 72 sources, evaluating uptake, clinical outcomes, and cost-effectiveness.

Uptake of the two-dose RZV series remained notably low. By 2020, only 10.8% of adults aged 50 and older had completed both doses, with 14.1% receiving at least one. Coverage was higher among those 65 and older (15.1% for two doses), but overall herpes zoster (HZ) vaccination, including the now-discontinued zoster vaccine live (ZVL), reached just 29.4% in this age group.

In contrast, other services showed stronger adoption. Influenza vaccination rates ranged from 54.2% (ages 50-64) to 75.2% (65 and older) in 2020. Pneumococcal vaccine coverage hit 67.5% for those 65 and up, while Td/Tdap reached 56.5%-69.8% across age brackets in 2019. Hepatitis B, recommended at the time for at-risk adults, saw 19.1% coverage in 2018. CRC screening achieved 74.2% in 2020, supported by its "A" grade from the U.S. Preventive Services Task Force (USPSTF).

Racial and ethnic disparities compounded the issue. RZV completion was higher among White (4.1%-8.6%) and Asian individuals compared to Black (2.5%-2.8%) or Hispanic (1.8%) adults. Similar patterns emerged for other vaccines, except influenza, where rates were more equitable.

Modeling studies projected substantial HZ prevention with RZV. At 100% first-dose coverage and varying second-dose rates, RZV could avert 35,000-103,603 HZ cases per million vaccinated over lifetimes, including complications like post-herpetic neuralgia (3,100-14,900 cases) and deaths (14-171). Real-world data showed RZV slashing HZ ophthalmicus incidence from 76.7 to 25.5 per 100,000 person-years.

Comparators also demonstrated impact. Influenza vaccines prevented up to 1.3 million cases seasonally among those 65 and older. Td/Tdap averted 410-3,285 pertussis cases over 35 years in similar cohorts. Hepatitis B models suggested 19.1%-24.1% fewer acute infections with broader coverage. Pneumococcal strategies reduced invasive disease by 30-57 cases per 100,000, though herd effects from pediatric programs contributed.

The number needed to vaccinate favored RZV at 10 to prevent one HZ case, versus 650-1,000 for hepatitis B and 1,800-5,290 for pneumococcal disease.

From a societal perspective, RZV's incremental cost-effectiveness ratios (ICERs) per quality-adjusted life-year (QALY) ranged from $1,407 (age 70) to $91,156 (age 50), often cost-saving at ages 60-80. This compared favorably to influenza ($8,833-$15,001 for high-dose versions), Tdap ($17,150-$336,108 versus Td), hepatitis B ($371,606-$541,461), pneumococcal ($15,000-$38,000), and CRC screening (dominant to $261,000).

A multi-disease model predicted all vaccines as cost-saving over 30 years at 2017 coverage levels, with pneumococcal yielding the highest benefit-cost ratio (2.01), followed by HZ (1.57). Boosting coverage could amplify savings, but RZV's underuse limits its potential.

These findings underscore RZV's compliance with the Affordable Care Act's no-cost preventative care requirements for payers. However, obstacles such as awareness, access, and completion of series remain, especially among underserved groups. The authors conclude that the clinical and economic value of RZV is comparable to or exceeds that of alternatives, advocating for prioritizing to address utilization disparities.

Population health officials may utilize this data for focused interventions, such as consolidated reminders for influenza vaccinations or colorectal cancer screenings. In 2022, ACIP broadened RZV recommendations to include immunocompromised adults aged 19 and older, and in 2024, extended pneumococcal recommendations to individuals aged 50 and older. Incorporating RZV into standard care may improve health outcomes and alleviate the substantial herpes zoster-related burdens, estimated in millions of cases and expenses each year.