Shingles, or herpes zoster, is a painful and potentially debilitating condition caused by the reactivation of the varicella-zoster virus, which also causes chickenpox. While shingles can affect anyone who has had chickenpox, it is more common in older adults or those with weakened immune systems. 

Fortunately, shingles can be prevented with the help of shingles vaccination. Two main vaccines, Shingrix and Zostavax, are currently available to protect against shingles. Understanding the differences between these two vaccines is crucial for making an informed decision about which one is best suited for your needs.

What is Shingrix?

Shingrix is the newer of the two shingles vaccinations and has quickly become the preferred vaccine due to its higher effectiveness and longer-lasting protection. It was approved by the U.S. Food and Drug Administration (FDA) in 2017 and is recommended for adults aged 50 and older.

Shingrix is a recombinant vaccine, meaning that it is made using pieces of the virus rather than the whole virus. This vaccine contains a protein that is found in the varicella-zoster virus, along with an adjuvant, a substance that enhances the body’s immune response to the vaccine. The combination of the protein and adjuvant helps the body develop a strong immune defense against shingles.

Shingrix is administered in two doses, with the second dose typically given two to six months after the first. The vaccine is highly effective at preventing shingles, with studies showing it is about 90% effective in adults over the age of 50.

What is Zostavax?

Zostavax is the older shingles vaccination and was approved by the FDA in 2006. Unlike Shingrix, Zostavax is a live attenuated vaccine, meaning it contains a weakened form of the varicella-zoster virus. The vaccine works by stimulating the immune system to recognize and fight off the virus if it is reactivated in the body.

Zostavax is administered as a single injection, typically given as a one-time shot to adults over the age of 60. While it is still effective in preventing shingles, its effectiveness decreases with age and over time. Studies have shown that Zostavax reduces the risk of shingles by about 51%, and the effectiveness of the vaccine diminishes after about five years.

Key Differences Between Shingrix and Zostavax

1. Vaccine Composition

One of the key differences between Shingrix and Zostavax lies in their composition. As mentioned, Shingrix is a recombinant vaccine, meaning it is made using a piece of the virus rather than the whole virus. Zostavax, on the other hand, is a live attenuated vaccine that contains a weakened form of the varicella-zoster virus.

The use of a recombinant approach in Shingrix allows for a stronger and more targeted immune response. This is why Shingrix is generally considered to be more effective than Zostavax in preventing shingles.

2. Effectiveness

Shingrix is significantly more effective than Zostavax in preventing shingles. Clinical trials have shown that Shingrix is about 90% effective at preventing shingles in adults aged 50 and older. Even in older adults, Shingrix remains highly effective, with minimal decline in effectiveness as people age.

In contrast, Zostavax has an effectiveness rate of around 51% in adults aged 60 and older. This effectiveness decreases further with age, making it less reliable for older adults. Furthermore, the protection offered by Zostavax wanes over time, with effectiveness dropping significantly after five years.

3. Duration of Protection

The duration of protection is another area where Shingrix has an advantage over Zostavax. Studies show that the protection provided by Shingrix lasts for at least four years, and it may last even longer. Some data suggest that the protection could last up to 10 years or more, although long-term studies are still ongoing.

On the other hand, the protection from Zostavax diminishes significantly after five years. This means that individuals who received Zostavax may need a booster shot to maintain protection, while those who receive Shingrix are less likely to need additional doses in the near future.

4. Age Recommendations

Shingrix is approved for adults aged 50 and older, and it is recommended for this age group as the first choice for shingles vaccination. In fact, the Centers for Disease Control and Prevention (CDC) now recommends Shingrix over Zostavax for the prevention of shingles in adults aged 50 and older, due to its higher effectiveness and longer-lasting protection.

Zostavax, on the other hand, is typically recommended for adults aged 60 and older. It was the first vaccine approved for shingles and is still used today, although it is now considered less effective than Shingrix. It’s important to note that Zostavax is not recommended for individuals who have weakened immune systems due to its live virus formulation.

5. Side Effects

Both Shingrix and Zostavax can cause side effects, though Shingrix is generally associated with a higher rate of side effects. The side effects of Shingrix are typically mild to moderate and include pain and swelling at the injection site, muscle pain, fatigue, headache, and fever. These side effects usually resolve within a few days.

Zostavax also has side effects, but they are generally less common and less severe than those associated with Shingrix. The most common side effects of Zostavax include redness, pain, or swelling at the injection site. In rare cases, Zostavax may cause a severe allergic reaction or a rash at the injection site.

It’s important to note that because Zostavax contains a live virus, it should not be given to individuals with weakened immune systems, such as those undergoing cancer treatment or those with HIV.

Which Vaccine Should You Choose?

The decision between Shingrix and Zostavax ultimately depends on several factors, including your age, health status, and risk factors for shingles. For most adults aged 50 and older, Shingrix is the preferred choice due to its higher effectiveness, longer-lasting protection, and stronger immune response. The CDC recommends Shingrix for individuals in this age group, even if they have previously received Zostavax.

Zostavax may still be appropriate for individuals aged 60 and older who are not eligible for Shingrix, or for those who have contraindications to the Shingrix vaccine. However, due to the waning effectiveness of Zostavax over time, Shingrix is generally considered the better option for shingles prevention.

Conclusion

Both Shingrix and Zostavax offer protection against shingles, but Shingrix is the more effective and longer-lasting of the two shingles vaccinations. Shingrix is recommended for adults aged 50 and older, while Zostavax may be appropriate for adults aged 60 and older. 

The decision between these two vaccines should be made in consultation with a healthcare provider, who can assess your individual health status and recommend the most suitable option for you. If you’re considering the shingles vaccination, be sure to discuss your options with your healthcare provider to make an informed choice about the vaccine that’s right for you.