The zoster vaccine is a vaccine that prevents shingles, a painful rash caused by the reactivation of the same virus that causes chickenpox. The current vaccine used in the United States is Shingrix, approved by the FDA in 2017. It replaced an older live vaccine called Zostavax, which was discontinued in November 2020. Shingrix is highly effective, preventing shingles in 97% of adults aged 50 to 69 and 91% of adults 70 and older.
How the Vaccine Works
After you recover from chickenpox, the varicella-zoster virus doesn’t leave your body. It goes dormant in nerve tissue and can reactivate decades later as shingles, especially as your immune system weakens with age or illness. The zoster vaccine trains your immune system to keep that dormant virus in check.
Shingrix is a subunit vaccine, meaning it doesn’t contain any live virus. Instead, it uses a lab-made copy of a single protein found on the surface of the varicella-zoster virus. This protein is essential for the virus to infect cells and spread between them, making it an ideal target. The vaccine pairs this protein with a specialized adjuvant, a combination of two immune-stimulating compounds derived from a bacterial source and a plant extract. These work together to activate immune cells in a way that produces both antibodies and a strong T-cell response, the branch of immunity most important for keeping the virus suppressed long term.
Who Should Get It
The CDC recommends Shingrix for all adults aged 50 and older, regardless of whether they remember having chickenpox or previously received the older Zostavax vaccine. Most adults in this age group carry the dormant virus even if they don’t recall being sick as children.
For adults aged 19 and older who have weakened immune systems, the recommendation is different. Since 2021, the CDC has recommended Shingrix for younger adults who are immunocompromised due to conditions like HIV, certain cancers, organ transplants, or medications that suppress immune function. These individuals face a higher risk of shingles reactivation, which is why the age threshold is lower.
Dosing Schedule
Shingrix requires two doses to reach full effectiveness. For most people, the second dose is given 2 to 6 months after the first. If you’re immunocompromised and would benefit from faster protection, the second dose can be moved up to as early as 1 to 2 months after the first. Both doses are necessary. A single dose provides some protection, but the full two-dose series is what produces the strong, lasting immune response the efficacy numbers are based on.
How Well It Works Over Time
The initial protection from Shingrix is among the highest of any adult vaccine: 97% effective in people aged 50 to 69 and 91% effective in those 70 and older. What makes it especially notable is how well that protection holds up.
A long-term follow-up study tracked vaccinated adults for up to 10 years. Through year 8, annual efficacy remained at or above 83%. By years 9 and 10, it dipped to roughly 73%, still a substantial reduction in risk. Across the full follow-up period (averaging about 9.6 years), overall efficacy against shingles was 89%. Immune markers at the 10-year mark were still more than five times higher than pre-vaccination levels, suggesting the immune system retains meaningful memory of the virus protein even a decade out. No booster dose is currently recommended.
Side Effects
Shingrix is known for producing noticeable short-term side effects, more so than many routine vaccines. The adjuvant system that makes it so effective also triggers a robust inflammatory response at the injection site and throughout the body. This is temporary and not dangerous, but it catches some people off guard.
The most commonly reported reactions include fever, pain at the injection site, chills, headache, fatigue, arm soreness, muscle aches, redness at the injection site, and nausea. Many people report that the second dose produces stronger side effects than the first. Symptoms typically peak within 24 to 48 hours and resolve within a few days. Planning your appointment before a day off can make the experience easier to manage.
Serious adverse events are rare. The vaccine has been in widespread use since 2017, with post-marketing surveillance covering millions of doses, and its safety profile has remained consistent with what clinical trials originally showed.
Cost and Insurance Coverage
Without insurance, Shingrix can cost over $300 for the full two-dose series. However, most people pay significantly less. Medicare Part D covers the shingles vaccine with no copayment and no deductible for plans that follow standard ACIP-recommended vaccine coverage rules. Most private insurance plans also cover it for adults who meet the age and medical criteria, though coverage details vary by plan.
Shingrix is available at most pharmacies, doctor’s offices, and community health clinics. If you’re getting it at a pharmacy, confirm that your specific insurance plan is accepted there, since out-of-pocket costs can vary depending on the provider and facility.
Why It Replaced Zostavax
Zostavax, a live-attenuated vaccine available since 2006, was the first shingles vaccine on the market. It worked reasonably well initially but had two significant limitations: its efficacy was lower (around 51% overall) and it waned substantially within a few years. It also couldn’t be given to immunocompromised patients because it contained live virus. Shingrix outperformed it on every measure, offering higher initial protection, better durability, and a safer profile for people with weakened immune systems. Zostavax was officially discontinued in the United States on November 18, 2020. If you received Zostavax in the past, the CDC still recommends getting the full two-dose Shingrix series.