Article written by Weston Malek
In our last post, we gave a brief overview of shingles and how Zostavax has been the primary prevention method for the past decade. Now, we’ll discuss the latest development in shingles prevention: the herpes zoster subunit vaccine, Shingrix®.
On October 25, 2017, the Center for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) announced endorsement of a new shingles vaccine, Shingrix, as the preferred vaccine to prevent shingles and shingles-related complications in adults 50 years and older. This marks a shift in current shingles vaccination policy in that Zostavax is no longer recommended as the standard prevention method. Additionally, adults age 50-59 years old who previously were at risk of developing shingles but not eligible for vaccination may now be protected.
Shingrix is a recombinant subunit vaccine given as a 2-dose series. It contains a combination of glycoprotein E, a herpes zoster virus (HZV) surface protein, and AS01B, an adjuvant suspension comprised of a purified soap bark tree extract (referred to as QS-21) and a Salmonella minnesota endotoxin fragment (monophosphoryl lipid A or MPL). This adjuvant mixture augments the immune system’s response to glycoprotein E, improving its ability to recognize and challenge to HZV reactivation before it can cause shingles. As a result, Shingrix was more than 90% effective in preventing shingles occurrence in clinical trials. The most common side effects to Shingrix were typically mild and common to receiving any vaccination: pain/inflammation at the injection site, muscle pain, tiredness, headaches, fever, and upset stomach.
The reason Shingrix has so quickly been adopted as the preferred shingles vaccine is because of how substantially it outperforms Zostavax. While Shingrix is more than 90% effective in preventing shingles rash, Zostavax is only 51% effective. Adequate protection lasts more than 4 years with Shingrix. By comparison, protection rapidly wanes after Zostavax immunization, with only about 20% of people still protected after 4 years. Likewise, Zostavax efficacy rates decrease with age – at the same time as the risk of shingles increases. Shingrix, however, appears to be effective in any age group. Perhaps the most important difference besides improved efficacy is the fact that Shingrix is a non-live, recombinant subunit vaccine while Zostavax is a live attenuated vaccine. While ACIP has not yet made an official statement recommending Shingrix for those who are immunocompromised, a non-live vaccine significantly reduces the concern for complications that prevents those with weakened immune systems from getting Zostavax.
In fact, the advantages of Shingrix are so impressive that ACIP has gone so far as to recommend that adults previous vaccinated with Zostavax should also receive Shringrix. Including these people and adults 50-59 years old who will now be eligible for shingles vaccination, a total of about 62 million Americans are recommended to receive Shingrix. But, for now, those individuals will have to wait: Shingrix is not expected to be available to the public until early 2018. Even then, it may take longer for insurance to begin covering Shringrix – though ACIP anticipates that it will be covered, just as Zostavax is currently.
- GlaxoSmithKline. CDC’s Advisory Committee on Immunization Practices recommends Shingrix as the preferred vaccine for the prevention of shingles for adults aged 50 and up [press release] (2017 Oct 25) [cited 2017 Nov 29]. Available from: https://www.gsk.com/en-gb/media/press-releases/cdc-s-advisory-committee-on-immunization-practices-recommends-shingrix-as-the-preferred-vaccine-for-the-prevention-of-shingles-for-adults-aged-50-and-up/
- Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. Hamborsky J, Kroger A, Wolfe S, eds. 13th ed. Washington D.C. Public Health Foundation, 2015.
- Shingrix [package insert]. Research Triangle Park (NC): GlaxoSmithKline LLC; 2017.