Study: General Practitioners Lack Understanding of Zoster Vaccine Risks, Guidelines for Immunocompromised Patients

Knowledge gaps exist for general practitioners (GPs) regarding the use of zoster vaccinations, specifically Zostavax, for patients who are immunocompromised, according to a recent study published in the Australian Journal of General Practice.

Though most GPs had good knowledge, notable gaps were identified in the awareness of recommendations, risks, and safety of zoster vaccines for people who are immunocompromised. The authors of the study also acknowledged Shingrix as an alternative vaccine for patients who are immunocompromised.

Though the safety of Zostavax is well documented, 3 deaths of patients who were immunocompromised occurred between 2017 and 2020 as a result of Zostavax vaccination administered despite contraindication. These deaths were followed by safety alerts intended to promote awareness of guidelines regarding Zostavax vaccination.

Previous research in 2017 indicated knowledge gaps about Zostavax and zoster vaccinations in GPs. The study authors sought to assess any changes in GP knowledge and behavior, considering the safety alerts and deaths that occurred.

Healthed, a private health education provider, distributed a national cross-sectional online survey to Australian GPs to assess knowledge regarding Zostavax, a live attenuated herpes zoster vaccine.

SurveyMonkey was used to conduct the survey between October 20 and 27, 2020. The survey was anonymous and voluntary, meaning responders were self-reporting GP status and demographics, as well as knowledge and clinical practice regarding zoster vaccination. The survey was distributed to attendees after a routine immunization webinar excluding information on zoster vaccination.

An 83% response rate was observed, with 502 of 605 GPs responding to the survey. Demographic information indicated that 52.7% of these physicians were 55-74 years of age, and 62% were female. Nearly 85% of respondents had administered zoster vaccines in the previous 12 months.

The majority of respondents had not reported adverse events (AEs) to Zostavax to the Therapeutic Goods Administration or their local public health authority over the past 12 months (83.1%). About 38% of respondents had seen minor AEs, but only 12.3% of respondents had seen a severe AE following Zostavax vaccination.

Of the respondents, 89% were aware that Zostavax is both funded and recommended for adults aged 70-79 years in Australia. Many respondents correctly answered that the vaccine is not routinely recommended for adults aged 50 to 59 years (65.9%) and not recommended for adults < 50 years of age (62.2%).

However, 10% incorrectly responded that immunocompromised status is not a contraindication to Zostavax and approximately 8% were unsure. The proportion of correct responses to 5 clinical scenarios assessing knowledge of Zostavax contraindications ranged from 25% to 82%.

Notably, according to the authors, two-fifths of respondents were unaware of recent safety alerts triggered by Zostavax-related deaths in immunocompromised people. These results indicate that notable knowledge gaps exist, despite most GPs having good knowledge regarding Zostavax, consistent with previous research.

The authors encourage GPs to use zoster vaccination resources, updated clinical advice, vaccination screening tools, and specialists to seek advice and information when uncertain about level of immunocompromise and appropriateness of Zostavax. They suggest that GPs should clearly explain both the benefits and risks to patients to ensure informed consent for zoster vaccination.

They also encourage further efforts to promote awareness of recommendations, particularly for people who are immunocompromised, as well as additional research on rates and outcomes of Zostavax administration errors.

Also, as one of the Australian Zostavax-related deaths was in a person with a mildly immunocompromising condition that was not contraindicated for vaccination, the authors recommend additional efforts to improve point-of-care precision in assessment of eligibility and contraindications.

They suggest the potential use of Shingrix, a non-live adjuvanted sub-unit herpes zoster vaccine, as the Australian Technical Advisory Group on Immunization has advised that Shingrix is preferred over Zostavax for the prevention of herpes zoster and associated complications in people aged ≥ 50 years, although they acknowledge that Zostavax remains an effective alternative vaccine for immunocompetent adults.

However, global shortages of Shingrix contribute to difficulties accessing this vaccine. Additionally, equity issues exist regarding the cost of Shingrix compared to Zostavax, which is funded by the Australian National Immunization Program for adults 70 and older.

Reference

Dey A, Rashid H, Sharma K, Phillips A, Li-Kim-Moy J, Manocha R, et al. General practitioner knowledge gaps regarding live attenuated zoster vaccination of immunocompromised individuals: An ongoing concern?. Australian Journal of General Practice. 2022;51(7). doi: 10.31128/AJGP-09-21-6175. Published July 7, 2022. Accessed July 11, 2022.