The painful rash known as shingles is caused by the varicella-zoster virus, the same virus responsible for chickenpox. After recovery, the virus remains dormant within nerve cells. Shingles occurs when the virus reactivates, causing a blistering rash that often follows a nerve path and can lead to intense, long-lasting pain. A highly effective vaccine exists to prevent this condition and its complications.
Official Recommendations for Vaccination
Major health organizations, such as the Centers for Disease Control and Prevention (CDC), recommend the recombinant zoster vaccine (RZV) for most adults to prevent shingles. All healthy adults aged 50 years and older should receive the vaccine. This guidance applies even if an individual does not recall having chickenpox, as over 99% of people over 50 already harbor the virus.
The recommendation also stands if a person has already experienced shingles, as the vaccine helps prevent future recurrences. Individuals who received the older, live attenuated shingles vaccine (Zostavax) should still receive the newer RZV for better and longer-lasting protection.
Adults aged 19 years and older who are or will be immunodeficient or immunosuppressed due to disease or therapy also have a strong recommendation for vaccination. These individuals are at increased risk of developing shingles at a younger age and experiencing more severe outcomes. Since RZV is not a live vaccine, it is safe for use in those with weakened immune systems.
What to Expect During the Vaccination Process
The current standard vaccine, RZV, is administered as a two-dose series. Completing both shots is necessary to achieve the full protection the vaccine offers. The second dose should typically be given intramuscularly between two and six months after the first.
If the second dose is delayed past the six-month window, the series does not need to be restarted; the individual should receive the second shot as soon as possible. For those who are or will be immunocompromised, the second dose may be given in a shorter interval of one to two months after the first. This shorter timeframe helps complete the series before periods of more intense immunosuppression.
RZV works by using a small piece of a protein from the varicella-zoster virus combined with an adjuvant, which helps create a stronger immune response. Achieving the full two-dose regimen provides a high level of protection against shingles and its most common long-term complication, postherpetic neuralgia.
Potential Side Effects and Safety Profile
The shingles vaccine has a strong safety profile, though it commonly causes temporary side effects. The most frequent reactions occur at the injection site, including pain, redness, and swelling, reported by the majority of recipients. Systemic side effects, such as muscle pain, tiredness, headache, shivering, and fever, are also common.
These common reactions are generally mild to moderate and typically resolve within two to three days. Experiencing these temporary symptoms indicates the body is building a strong immune response. For about one in six people, these side effects may be severe enough to temporarily prevent them from doing their normal daily activities.
In rare instances, a severe allergic reaction, such as anaphylaxis, may occur, requiring immediate medical attention. Contraindications include a history of a severe allergic reaction to any component of the vaccine or to a previous dose. An increased risk of Guillain-Barré syndrome, a rare neurological disorder causing muscle weakness, was also observed in post-marketing studies following vaccination.
The risk of these temporary side effects or rare adverse events must be weighed against the significant pain and potential for long-term nerve damage from a shingles infection. Postherpetic neuralgia, the most common complication, can cause pain lasting months or even years after the rash has cleared.