From the Guidelines
If you've only received one dose of the shingles vaccine, you should get a second dose to complete the vaccination series, as the current recommended shingles vaccine, Shingrix, requires two doses given 2-6 months apart for full protection. The implications of receiving only one dose of the Herpes Zoster (Shingles) vaccine are that you are not fully protected against shingles, which can cause painful rash and potentially serious complications, especially in older adults 1.
Importance of Second Dose
The vaccine works by boosting your immune system's ability to recognize and fight the varicella-zoster virus, which causes both chickenpox and shingles. Shingrix is approximately 97% effective at preventing shingles when both doses are received, but protection is incomplete with just one dose 1.
Vaccine Efficacy and Safety
The recombinant zoster vaccine, Shingrix, has been shown to be more effective than the live zoster vaccine, Zostavax, in preventing shingles and postherpetic neuralgia (PHN) 1. The safety data from the ZOE-50 and ZOE-70 trials showed that there was no difference between the vaccinated and placebo groups in the incidence of serious adverse events (SAEs) and deaths, however, the vaccinated group had a significantly higher incidence of grade 3 injection site reactions and systemic symptoms compared to the placebo group 1.
Recommendations
The Centers for Disease Control and Prevention (CDC) recommends 2 doses of recombinant zoster vaccine (RZV, Shingrix) 2 to 6 months apart as the preferred vaccine over zoster vaccine live (ZVL, Zostavax) for immunocompetent adults 50 years or older, including patients who are dialysis dependent 1.
Key Points
- Shingrix requires two doses given 2-6 months apart for full protection
- One dose of Shingrix does not provide complete protection against shingles
- Shingrix is approximately 97% effective at preventing shingles when both doses are received
- The vaccine works by boosting your immune system's ability to recognize and fight the varicella-zoster virus
- Side effects from the second dose are similar to the first—typically arm soreness, fatigue, or mild flu-like symptoms that resolve within a few days 1.
From the Research
Implications of Receiving Only One Dose of the Herpes Zoster (Shingles) Vaccine
- The effectiveness of a single dose of the Herpes Zoster vaccine is lower compared to the recommended two-dose regimen, with a vaccine effectiveness of 56.9% (95% CI, 55.0-58.8) 2.
- Receiving only one dose of the vaccine may not provide optimal protection against herpes zoster and postherpetic neuralgia, as the two-dose regimen has been shown to have a higher vaccine effectiveness of 70.1% (95% CI, 68.6-71.5) 2.
- The live attenuated zoster vaccine (LZV) has been shown to be effective in preventing herpes zoster for up to three years, but the effectiveness of a single dose is not well established 3, 4, 5.
- The recombinant zoster vaccine (RZV) has been shown to be effective in preventing herpes zoster for up to three years, with a higher vaccine effectiveness when two doses are administered 3, 4, 2.
Adverse Events and Safety
- Receiving only one dose of the vaccine may still result in adverse events, such as injection-site reactions, systemic symptoms, and local symptoms, although the risk may be lower compared to the two-dose regimen 3, 4, 2.
- The safety profile of the vaccine is generally favorable, with most adverse events being mild to moderate in intensity 3, 4, 5, 2.