Megan Polanin, PhD, National Center for Health Research: September 13, 2017
Thank you for the opportunity to speak today. My name is Dr. Megan Polanin. I am a Senior Fellow at the National Center for Health Research. Our research center analyzes scientific and medical data and provides objective health information to patients, providers, and policymakers. We do not accept funding from industry, so I have no conflicts of interest.
An effective shingles vaccine is important for public health. As patients get older, they are more likely to develop long-term pain, or post-herpetic neuralgia (PHN), as a complication of shingles. This pain can be severe and chronic. There is no cure, and treatments do not reliably relieve pain for all patients. The only way to reduce the risk of developing shingles and PHN is to get vaccinated.
Like any public health strategy, a vaccine’s benefits must outweigh its risks. Based on available research, Shingrix has displayed significant benefits compared with the current shingles vaccine on the market, Zostavax:
1) Shingrix showed much higher levels of vaccine efficacy (e.g. 97% for 50+ and 90% in 70+) than the current shingles vaccine. Zostavax only reduces the occurrence of shingles by about half for patients 60 and older, and its effectiveness declines as patients age. For patients 80 and older, Zostavax is only 18% effective.
2) Shingrix has displayed efficacy in preventing PHN in patients 50 years and older by preventing shingles. Zostavax is less effective in preventing PHN because it is less effective at preventing shingles. For people who were vaccinated and still developed shingles, Zostavax helped to reduce the duration of PHN, but not the severity of pain.
3) Shingrix can potentially be administered to vulnerable patients with weakened immune systems. Zostavax is a live attenuated vaccine, and therefore is not safe for people with weakened immune systems, such as patients who have had radiation or chemotherapy and those with HIV.
Shingrix requires two doses while Zostavax is a one-time injection. However, that is a small price to pay for a much more effective vaccine.
Post-licensure studies are critical as we need long-term data to evaluate Shingrix’s long-term efficacy for patients 50 years and older. This is especially relevant since Zostavax may no longer be effective 8 to 11 years after vaccination. The company’s proposed long-term follow-up studies will help to determine whether Shingrix is able to protect older adults from contracting shingles as they age. It is essential that those studies be completed in a timely matter and that the company provide adequate incentives to patients to stay in the study.
We do have some concerns about risks. Patients treated with Shingrix had a higher rate of common adverse reactions (e.g. 74% vs. 9% for placebo group), such as pain, swelling, and fatigue. In addition, one serious adverse event, supraventricular tachycardia, was reported more frequently for patients vaccinated with Shingrix compared with patients who had not during the 30-day post-vaccination period. We are also concerned about optic ischemic neuropathy, which was reported within 30 days by 2 patients, within 2 months by another patient, and not reported at all in the placebo group. These issues warrant further attention.
For that reason, we agree with the company and FDA reviewers that continued pharmacovigilance is critical to evaluate adverse events for patients vaccinated with Shingrix compared to those vaccinated with Zostavax and those with placebo. This should include uncommon adverse events observed soon after vaccination and any other adverse events that may arise with larger sample sizes in longer-term studies.
We concur with the FDA’s requests that the company specifically address risks of inflammation from the vaccine, which can lead to the some of the adverse events reported during pre-licensure studies (e.g. optic ischemic neuropathy, gout).
We urge this Advisory Committee to recommend that the FDA require critical post-approval long-term studies to further evaluate the efficacy and safety of Shingrix. We also strongly recommend that the company conduct subgroup analyses to ensure that the vaccine is safe and effective for both women and men and also people of color.
Thank you for the opportunity to share our perspective.
The Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted 11-0, that the available data are adequate to support the efficacy and safety of Shingrix when administered to adults 50 years of age and older.