Shingles, also known as herpes zoster, is a painful viral infection caused by the varicella-zoster virus, the same virus that causes chickenpox. Vaccination is an effective way to prevent shingles and its complications, including postherpetic neuralgia (PHN).
Two vaccines are available for shingles prevention: Shingrix and Zostavax. In this article, we’ll explore the differences between these two vaccines to help individuals make informed decisions about shingles vaccination.
Understanding Shingrix
Shingrix is a recombinant subunit vaccine developed by GlaxoSmithKline (GSK) to prevent shingles in adults aged 50 years and older. It contains a non-live antigen called glycoprotein E (gE), which stimulates the immune system to produce a strong and long-lasting immune response against the varicella-zoster virus.
Shingrix is administered as a series of two doses, with the second dose given 2 to 6 months after the first dose. It is recommended by the Centers for Disease Control and Prevention (CDC) as the preferred vaccine for shingles prevention due to its high efficacy and effectiveness, even in older adults.
Key Features of Shingrix
- High Efficacy: Clinical trials have shown that Shingrix is highly effective in preventing shingles and its complications, with an efficacy rate of over 90% in adults aged 50 years and older.
- Long-lasting Protection: Shingrix provides long-lasting protection against shingles, with studies demonstrating durable immunity for up to 8 years after vaccination.
- Two-Dose Series: Shingrix is administered as a series of two doses, given intramuscularly in the upper arm. The second dose is essential for maximizing the vaccine’s effectiveness and ensuring long-term protection against shingles.
- Minimal Side Effects: Common side effects of Shingrix include pain, redness, and swelling at the injection site, as well as mild systemic symptoms such as fatigue, headache, and muscle pain. These side effects are typically mild and transient, resolving within a few days.
Exploring Zostavax
Zostavax is a live attenuated vaccine developed by Merck & Co. to prevent shingles in adults aged 50 years and older. Unlike Shingrix, which contains a non-live antigen, Zostavax contains a weakened form of the varicella-zoster virus. Zostavax is administered as a single dose injection, and it works by stimulating the immune system to produce a protective response against the virus.
Key Features of Zostavax
- Moderate Efficacy: Clinical trials have shown that Zostavax is moderately effective in preventing shingles, with an efficacy rate of around 51% in adults aged 60 years and older. However, its effectiveness wanes over time, leading to reduced protection against shingles and its complications.
- Single-Dose Administration: Zostavax is administered as a single dose injection, making it a convenient option for individuals who prefer a one-time vaccination.
- Limited Duration of Protection: The protective effect of Zostavax diminishes over time, with studies indicating that its effectiveness declines significantly after the first year of vaccination. As a result, booster doses are not recommended, and individuals may require revaccination with Shingrix for continued protection against shingles.
- Potential Side Effects: Common side effects of Zostavax include redness, swelling, and pain at the injection site, as well as mild systemic symptoms such as headache, fatigue, and gastrointestinal upset. Rare but serious adverse events, including allergic reactions and disseminated varicella infection, have also been reported.
Conclusion
Both Shingrix and Zostavax are effective vaccines for preventing shingles in adults aged 50 years and older. However, Shingrix is preferred over Zostavax due to its higher efficacy, longer-lasting protection, and safer profile. Individuals considering shingles vaccination should consult with their healthcare providers to determine the most appropriate vaccine based on their age, medical history, and individual risk factors. Vaccination remains the best strategy for reducing the risk of shingles and its associated complications, including PHN.
