Cost-effectiveness of Shingrix vaccination and revaccination in immunocompetent and immunosuppressed adults in England: a repeated cross-sectional study and economic modelling analysis

Study type
Protocol
Date of Approval
Study reference ID
24_004281
Lay Summary

Shingles is a painful rash that about one in four people in England get at least once, usually as older adults. Most of the time, the rash heals after 2–4 weeks, but about one in 20 people with shingles get postherpetic neuralgia (PHN). PHN causes severe pain that lasts from 3 months to many years and can make people’s quality of life worse.

The same virus that causes chickenpox causes shingles. After someone recovers from chickenpox, the virus stays in their body for the rest of their life. Shingles happens when the virus wakes up and damages a person’s nerves. Older people and people with weaker immune systems are more likely to get shingles and PHN.

There is no cure for shingles, but vaccines can prevent it. In 2013, the NHS started offering a shingles vaccine called Zostavax to people aged 70-79. This has protected many people from shingles. Now there is a new vaccine, called Shingrix, that works better than Zostavax and can be used in people with weaker immune systems too.

The NHS has asked us to answer four questions to help them to make decisions about Shingrix:
(1) Should Shingrix be given to people over 80?
(2) Should people who got the older vaccine (Zostavax) now take Shingrix?
(3) Should older people take a booster dose of Shingrix to stop the protection from wearing off?
(4) Should people with weaker immune systems take booster doses of Shingrix?

Technical Summary

We will conduct a cost-effectiveness analysis of Shingrix vaccination in adult immunocompetent and immunosuppressed populations in England.

We will estimate the age-specific incidence of shingles and postherpetic neuralgia in adults aged 18 and older in single-year age bands, by study year over the period 1st September 2003 to the latest available data at the time of the study, in both immunocompetent and immunosuppressed adults. We will define individuals with immunosuppression using relevant primary-care recorded morbidity codes and prescriptions. We will estimate cases of shingles and PHN by using primary and secondary care records for zoster and for PHN diagnosis and treatment. We will also estimate zoster-related mortality and background mortality using linked ONS death data. Zoster incidence will have decreased since 2013 due to the use of the Zostavax vaccine; we will use previously estimated vaccine effectiveness [15] and UKHSA-provided age- and year-specific uptake data to adjust for this decrease to understand what incidence rates may have been in the absence of vaccination. We will use the measured incidence rates to project the incidence of shingles and PHN forwards for use in our cost-effectiveness model, omitting data from the COVID-19 pandemic years due to reduced contact with health care during this time.

Then, we will use a Monte Carlo decision tree model to estimate the potential impact of different Shingrix vaccination strategies, including: (1) vaccination of elderly individuals aged 80+ who have not yet received shingles vaccination; (2) revaccination of Zostavax recipients with Shingrix; (3) a booster dose of Shingrix for elderly individuals once the Shingrix vaccine is offered to 60-year-olds; and (4) booster doses of Shingrix for immunosuppressed individuals. We will ascertain the most cost-effective vaccination strategies by calculating incremental cost-effectiveness ratios and calculating the threshold price at which a vaccination strategy becomes cost-effective.

Health Outcomes to be Measured

Primary outcomes: incidence of herpes zoster (shingles); incidence of postherpetic neuralgia; incidence of zoster-related hospitalisation; incidence of zoster-related mortality
Secondary outcomes: incidence of non-zoster-related (background) mortality

Collaborators

Nicholas Davies - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Nicholas Davies - Corresponding Applicant - London School of Hygiene & Tropical Medicine ( LSHTM )
Anne Suffel - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Chu-Chang Ku - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Edward Parker - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Eleanor Barry - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Harriet Forbes - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Kathryn Mansfield - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )

Linkages

HES Admitted Patient Care;ONS Death Registration Data