A key advisory panel to the Centers for Disease Control and Prevention (CDC) has recommended the use of the new Shingrix vaccine (GlaxoSmithKline) over the existing Zostavax vaccine (Merck) for the prevention of shingles in adults 50 years of age and older. The Advisory Committee on Immunization Practices (ACIP) also recommended that adults who previously received Zostavax be given Shingrix.
The ACIP recommendations (which are limited to immunocompetent adults) mean up to 62 million additional adults in the U.S. should be immunized: approximately 42 million 50–59 years of age and 20 million who have previously been vaccinated against shingles (herpes zoster). The previous ACIP recommendation applied to adults 60 years of age and older, only 31% of whom have been immunized against shingles.
The FDA approved Shingrix (zoster vaccine recombinant, adjuvanted) on October 20, 2017. The approval was based on a comprehensive phase 3 clinical trial program involving 38,000 adults to evaluate the vaccine's efficacy, safety, and immunogenicity.
In a pooled analysis of these studies, Shingrix demonstrated efficacy against shingles greater than 90% across all age groups, as well as sustained efficacy over a follow-up period of four years. By preventing shingles, Shingrix also reduced the overall incidence of postherpetic neuralgia (PHN), a form of chronic nerve pain lasting from at least three months up to several years and the most common complication associated with shingles.
The most common side effects of Shingrix are pain, redness, and swelling at the injection site, muscle pain, tiredness, headache, shivering, fever, and upset stomach, which are related to the immune system responding to the vaccine. Based on available data, the majority of reactions to the vaccine were transient and mild to moderate in intensity, lasting less than three days.
The ACIP recommendations will be forwarded to the director of the CDC and the Department of Health and Human Services for review and approval. Once approved, the final recommendations will be published in a future Morbidity and Mortality Weekly Report (MMWR).
Shingles is caused by the reactivation of the varicella zoster virus (VZV), the same virus that causes chickenpox. Nearly all older adults have the VZV dormant in their nervous system, waiting to reactivate with advancing age. As people age, the cells in the immune system lose the ability to maintain a strong and effective response to VZV reactivation.
Shingles typically presents as a painful, itchy rash that develops on one side of the body and can last for two to four weeks. The pain associated with shingles is often described as burning, shooting or stabbing. Even once the rash is gone, a person can experience PHN. One in three Americans will develop shingles in their lifetime.
Shingrix is a non-live, recombinant subunit vaccine that combines an antigen, glycoprotein E, and an adjuvant system, AS01B, intended to generate a strong and long-lasting immune response that can help overcome the decline in immunity as people age.