Herpes zoster, more commonly known as shingles, is a viral infection that causes a painful rash, often appearing on one side of the body. It is caused by the varicella-zoster virus, the same virus responsible for chickenpox. Once someone recovers from chickenpox, the virus remains dormant in the body. Years later, it can reactivate as shingles, especially in older adults or those with weakened immune systems.
The herpes zoster vaccine is designed to help prevent shingles or reduce its severity if it does occur. But a common question that arises is whether the herpes zoster vaccine is live. Let’s take a closer look at what a live vaccine is, whether the herpes zoster vaccine is live, and what it means for your health.
What Is a Live Vaccine?
A live vaccine contains a version of the virus or bacteria that has been weakened or attenuated so that it cannot cause disease in a healthy person. The goal of a live vaccine is to stimulate the immune system by mimicking a natural infection. However, because the virus is weakened, it typically cannot cause the full-blown disease. In contrast, inactivated or killed vaccines use a virus or bacteria that has been killed or inactivated so that it cannot replicate, but it still triggers an immune response.
Live vaccines have been used for many years to prevent diseases like measles, mumps, rubella (MMR), yellow fever, and others. These vaccines are very effective, and they help the immune system create long-lasting protection against the disease.
The Herpes Zoster Vaccine
There are two main types of herpes zoster vaccines currently available:
- Zostavax
- Shingrix
Both vaccines are used to prevent shingles, but they are different in terms of composition and effectiveness. To understand whether the herpes zoster vaccine is live, we need to look at the ingredients of these two vaccines.
Zostavax: The Live Vaccine
Zostavax is an older herpes zoster vaccine. It is made from a live, attenuated varicella-zoster virus. This means that Zostavax is indeed a live vaccine. The virus in the vaccine is weakened, so it doesn’t cause chickenpox or shingles in healthy individuals. However, people with weakened immune systems may be at risk of developing a mild form of the disease, as the live virus in the vaccine can potentially cause infection in those with compromised immune systems.
Zostavax is recommended for people 60 years and older to reduce the risk of shingles. It is administered as a single injection, typically given in the upper arm. This vaccine has been shown to reduce the risk of shingles by about 50% and the risk of postherpetic neuralgia (a common complication of shingles) by 67%.
However, due to its relatively lower effectiveness compared to newer vaccines, Zostavax is no longer widely used in favor of Shingrix.
Shingrix: The Recombinant Vaccine
Shingrix is a newer vaccine that has largely replaced Zostavax for shingles prevention. Unlike Zostavax, Shingrix is not a live vaccine. It is a recombinant vaccine, meaning that it does not contain live virus particles. Instead, it contains a protein from the varicella-zoster virus, which helps trigger an immune response without using the whole virus. Shingrix also contains an adjuvant, which boosts the body’s immune response to the vaccine.
Because Shingrix is not a live vaccine, it can be given to people with weakened immune systems, such as those undergoing chemotherapy or organ transplant patients. It is also much more effective than Zostavax, providing more than 90% protection against shingles in healthy adults over 50 years old. It is administered as a two-dose series, with the second dose given two to six months after the first dose.
Why Does It Matter if the Herpes Zoster Vaccine is Live?
Whether the herpes zoster vaccine is live or not has significant implications for different groups of people. Here’s why:
1. Safety for Immunocompromised Individuals
Live vaccines, such as Zostavax, can pose risks for people with weakened immune systems. For example, those with HIV, cancer, or organ transplant recipients might not be able to safely receive a live vaccine like Zostavax. In these cases, the weakened virus in the live vaccine might cause illness instead of preventing it. This is why non-live vaccines, such as Shingrix, are generally preferred for these individuals.
On the other hand, since Shingrix is not a live vaccine, it can be safely given to immunocompromised people, providing them with protection against shingles without the risk associated with live vaccines.
2. Effectiveness of the Vaccine
Live vaccines like Zostavax provide a reasonable level of protection but tend to lose effectiveness over time. As mentioned earlier, Zostavax reduces the risk of shingles by about 50% and postherpetic neuralgia by 67%. However, the effectiveness decreases as people age. This is why Shingrix, a non-live vaccine, is preferred due to its higher efficacy (over 90%).
For older adults, who are at the highest risk for shingles, getting a vaccine with better protection is essential. This is one of the reasons why Shingrix is now the preferred vaccine for shingles prevention, replacing Zostavax.
3. Vaccination Frequency and Duration
Because Shingrix offers longer-lasting protection compared to Zostavax, people who receive the Shingrix vaccine generally need only two doses. In contrast, Zostavax requires a single dose, but its protection diminishes over time. A person who gets Zostavax may need to receive additional doses later in life for continued protection, whereas Shingrix offers prolonged protection.
What Are the Side Effects of the Herpes Zoster Vaccine?
Both Zostavax and Shingrix have side effects, but they differ due to the nature of the vaccines.
Side Effects of Zostavax
Since Zostavax is a live vaccine, it can cause some mild side effects similar to a mild case of chickenpox. The most common side effects include:
- Pain, redness, or swelling at the injection site
- Headache
- Fever
- Fatigue
In rare cases, a person receiving Zostavax could develop a mild form of shingles or chickenpox. This is because Zostavax contains a weakened form of the varicella-zoster virus. However, this is uncommon and usually happens in people with weakened immune systems.
Side Effects of Shingrix
Shingrix, being a recombinant vaccine, does not carry the risk of causing shingles. However, it can cause side effects that are somewhat more intense but are generally short-lived. These side effects can include:
- Pain, redness, or swelling at the injection site
- Muscle pain or joint pain
- Fatigue
- Fever
- Chills
- Headache
These side effects usually last for a few days after vaccination and are generally a sign that the immune system is responding to the vaccine.
Who Should Get the Herpes Zoster Vaccine?
The herpes zoster vaccine is primarily recommended for older adults, particularly those over 50 years old. Shingles is more common in this age group, and the risk increases with age. Even people who have had chickenpox in the past are at risk of developing shingles later in life.
For people over 50, Shingrix is the preferred vaccine. The Centers for Disease Control and Prevention (CDC) recommends that adults over 50 get the Shingrix vaccine, even if they have had shingles before or received Zostavax in the past.
Zostavax is generally recommended only for adults over 60 who prefer a single-dose vaccine and cannot receive Shingrix.
Conclusion
In summary, whether the herpes zoster vaccine is live or not depends on the specific vaccine being used. Zostavax, the older shingles vaccine, is a live, attenuated vaccine, while Shingrix, the newer and more effective option, is not a live vaccine. Shingrix is recommended for most adults over 50 because it offers better protection and is safer for people with weakened immune systems.
If you’re considering getting vaccinated for shingles, it’s important to talk to your doctor to determine which vaccine is best for you based on your health status and age.
Related topics
