The new vaccine for shingles—now recommended for all healthy adults age 50 and over—is significantly more effective than the original shingles vaccine, according to UMass Medical School immunologist Robert Finberg, MD.
Shingles is caused by the varicella-zoster virus, which initially causes chicken pox. The virus remains dormant in nerve cells, where it can be reactivated years later. The new vaccine, named Shingrix, is a dead recombinant protein vaccine. Zostavax, a live zoster vaccine in use since 2006, will continue to be available.
Dr. Finberg, the Richard M. Haidack Professor of Medicine and chair and professor of medicine, comments on the new vaccine from scientific and clinical perspectives in this Expert’s Corner Q&A.
Why is the new shingles vaccine important?
This vaccine is much more effective than the old one. It is a very important advance because, as the Centers for Disease Control reports, about one in three people will get herpes zoster at some time in their lives. The longer you live, the more likely you are to get it, with most cases in those over 60, although cases do occur in younger people. One out of six of those who get zoster will have severe lingering nerve pain called post-herpetic neuropathy, which can last for months or even years, and can be totally disabling.
How much more effective is Shingrix than Zostavax?
Shingrix is 97 percent effective at ages 50 to 59, while Zostavax is about 70 percent effective. That efficacy persists in older people, even those over 80, where most of the disease occurs. CDC recommends the Shingrix vaccine (given as two doses, 2 to 6 months apart), to those age 50 and up instead of waiting until age 60 as with Zostavax.
What is different about the new vaccine?
It is made of a recombinant glycoprotein instead of live virus. And it includes a new adjuvant, an additive that boosts effectiveness. The Shingrix vaccine contains both a lipid formulation and a saponin, which is a plant substance that enhances the response to the viral protein. Unlike the adjuvant, alum, which has had mixed results, this new formulation has not been used in vaccines before and appears to be very effective.
Why is it more effective?
Why this vaccine is more effective is the most interesting question for immunologists, but we don’t know the answer at this time. Having worked on the immune response to zoster, as well as with herpes simplex, Epstein-Barr virus and cytomegalovirus—all herpes viruses—everything I know as an immunologist would have told me the old one would be better, but in fact, there’s no comparison to the efficacy of this new vaccine.
The novel adjuvant may be the reason, or it may be something about the host response to this glycoprotein that makes the new vaccine more effective. Everything we know tells us that T-cells are more important than antibodies for herpes zoster immunity, and everything we know about dead vaccines is that they are much better at inducing antibodies (a B cell product), than T cells, so for an immunologist it is a surprising finding. But there’s no doubt it’s dramatically different and dramatically better. Nature can surprise you.
What are you telling patients?
The only contraindications for Shingrix for healthy adults are severe allergic responses to any of the vaccine components. The vaccine should not be administered to patients with an acute episode of shingles, and safety and effectiveness for different groups of immunocompromised patients are still under review. Health care providers will administer two doses at two to six months apart, as recommended by the Advisory Committee on Immunization Practices of the Centers for Disease Control as the vaccine becomes widely available. Unvaccinated individuals 60 and older, who can get Zostavax now, might consider waiting for Shingrix since they will want to get it anyway, as will older patients who have already received Zostavax.
I would just caution that while Shingrix is licensed and available, many insurance companies do not yet cover it. Patients might want to consider waiting until insurers add it to their formularies.
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