The recombinant zoster vaccine Shingrix, given as two doses, prevents more than 90 percent of shingles cases in adults 50 and older, per the efficacy figures CDC cites from its pivotal trials, and the CDC's advisory committee has recommended it for all immunocompetent adults aged 50 and older since 2017. The disease it prevents is common: CDC estimates about one in three people in the United States will develop shingles in their lifetime, translating to roughly one million cases each year.
This article explains what shingles is, who the vaccine is for, how the two-dose schedule works, and what the side effects involve. Newspaper Daily publishes information, not medical advice; anyone deciding on vaccination should review their medical history with a clinician or pharmacist.
What is shingles, and who gets it?
Shingles, or herpes zoster, is a reactivation of the varicella-zoster virus, the same virus that causes chickenpox. After chickenpox resolves, the virus hides in nerve ganglia and can reactivate decades later, traveling along a nerve to produce a painful, blistering rash, usually on one side of the torso or face. The signature complication is postherpetic neuralgia, nerve pain that persists for months or years after the rash heals. CDC cites figures showing postherpetic neuralgia affects about 10 to 13 percent of shingles cases, with the risk rising sharply with age.
Age is the dominant risk factor because cellular immunity to the virus wanes over time. More than half of cases occur in adults 50 and older, per CDC data, and people with weakened immune systems face elevated risk at any age. A person cannot catch shingles from someone else, but a person with active shingles blisters can transmit the virus to someone never exposed to chickenpox, who would then develop chickenpox rather than shingles.
Who is the vaccine recommended for?
The CDC's advisory committee, ACIP, recommends Shingrix in two groups. The first is all immunocompetent adults aged 50 and older, a recommendation in place since 2017. The second, added in 2021, is immunocompromised adults aged 19 and older, a group in which the committee judged the benefits of earlier vaccination outweighed the uncertainty. The recommendation applies whether or not a person remembers having had chickenpox, because CDC considers essentially all US-born adults born before 1980 to have been exposed to the virus.
Two other groups come up often in practice. People who already had shingles are still advised to get vaccinated, since an episode does not reliably prevent another; recurrence rates run about 3 percent or so in CDC-cited studies. And people who received the older live zoster vaccine Zostavax, discontinued in the United States as of 2020, are advised to be revaccinated with Shingrix, which replaced it because of superior and longer-lasting protection.
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How well does Shingrix work, and for how long?
The efficacy numbers come from two pivotal randomized trials involving about 30,000 adults, cited by CDC and the FDA. In adults aged 50 to 69, two doses prevented 97 percent of shingles cases; in adults 70 and older, efficacy was 91 percent, and protection against postherpetic neuralgia was similarly high. The durability data, summarized in follow-up publications CDC references, show efficacy holding above roughly 85 percent through four years, a marked contrast with the older live vaccine, whose protection faded substantially within five years.
Protection is measured against shingles and its complication, not against chickenpox. Shingrix is not a chickenpox vaccine, and CDC notes it has not been studied for preventing primary varicella infection.
What is the dosing schedule?
Shingrix is given as two intramuscular doses, with the second dose typically two to six months after the first, per FDA labeling. For immunocompromised adults, ACIP allows the second dose sooner, one to two months after the first, at the clinician's discretion. If the second dose is delayed, CDC guidance states it does not need to be restarted; the series is simply completed.
What are the side effects?
Shingrix is a reactive vaccine, meaning it provokes a noticeable immune response. In the trials CDC cites, the most common complaints were pain, redness, and swelling at the injection site, plus muscle aches, fatigue, headache, shivering, fever, and gastrointestinal upset. Roughly one in six recipients aged 50 to 69 and one in five over 70 reported enough systemic symptoms to affect daily activity, typically resolving within two to three days. Planning a lighter schedule for the two days after each dose is a commonly shared practical tip among clinicians, though it is not an official requirement.
A rare finding, described in a 2021 JAMA Internal Medicine analysis and acknowledged by CDC, associated Shingrix with a small transient increase in ischemic stroke risk in the one to 41 days after vaccination, on the order of a fraction of a case per thousand doses. CDC continues to recommend the vaccine because the disease burden it prevents exceeds that risk. Guillain-Barré syndrome has also been observed at a very low rate, about three additional cases per million doses in adults 65 and older, per FDA labeling, a signal the FDA required be added to the warning section without changing the recommendation.
Can Shingrix be given with other vaccines?
Yes. ACIP states Shingrix can be co-administered with other adult vaccines, including COVID-19, influenza, and pneumococcal vaccines, and many pharmacies offer combination visits. Immunocompromised adults should time vaccination with their treating specialists, since some immunosuppressive regimens argue for specific scheduling.
When to see a doctor
A shingles rash near the eye requires urgent medical attention, because ocular involvement can threaten vision. A rash that becomes widespread, a fever accompanying the rash, or symptoms in an immunocompromised person also warrant prompt evaluation, since antiviral treatment such as acyclovir works best when started within 72 hours of the rash appearing. After vaccination, difficulty breathing, swelling of the face or throat, hives, or a rapid heartbeat signal a possible severe allergic reaction and require emergency care. Persistent nerve pain after a shingles episode should be raised with a clinician as well, because early treatment of postherpetic neuralgia improves outcomes.