Do I Need the New Shingles Vaccine if I Already Got the Old One?

The CDC recommends that everyone over 50 years of age gets two doses of the Shingrix vaccine. Is this necessary? How effective is the vaccine, and are there side effects you should be concerned about?

Key takeaways:

What is shingles?

Shingles (also called “herpes zoster”) is a painful skin condition with a rash and blisters. Itching and tingling frequently occur where the rash will appear, often as a line or stripe around either the left or right side of the body.

The rash can appear on the face as well, sometimes affecting the eye. The blisters typically scab over in 7 to 10 days, and the rash fully clears within about 2 to 4 weeks. Other symptoms include fever, headache, chills and upset stomach.

What causes shingles?

The virus that causes chickenpox—varicella-zoster virus or VZV—stays dormant in the body after infection. The virus can reactivate later in life and cause shingles.

The reason the rash resurfaces in a specific pattern is the VZV stays dormant in nerve cells in the dorsal or cranial root ganglia. These ganglia contain the cell bodies of sensory neurons.

The axons extending from the ganglia reach out to peripheral tissues, such as skin and muscle. These nerves carry touch, heat, pain, pressure, and vibration signals along their axons back to the brain.

When VZV reactivates, it spreads via the axons arising from the ganglia. This is why the rash appears as a pattern across the face or torso, depending on the ganglia affected.

How common is shingles?

The CDC estimates that 1 in 3 people living in the US will get shingles in their lifetime. While it usually only develops once, it is possible to get shingles more often.

What increases the risk of shingles?

There are two main risk factors for shingles:

  1. Age. The most common risk factor is age—you are more likely to get shingles as you get older.
  2. Impaired immunity. People who are immune compromised are more likely to get shingles.

What is post-herpetic neuralgia?

Post-herpetic neuralgia (PHN) is the pain that can follow shingles for at least 30 days after the rash develops. In about 10 to 18% of people with shingles, damage to the sensory nerves can cause longer-term pain. The range of symptoms can include burning sensations, or pain ranging from sharp and stabbing, to deep and aching.

I got Zostavaz already, should I get Shingrix?

Yes, the CDC recommends that anyone 50 years and older should get Shingrix (GlaxoSmithKline) even if they got Zostavax (Merck) previously. This is because studies found that the protection of Zostavax waned significantly with age, leaving older people at risk.

The two vaccines are manufactured differently as well. Although Zostavax is no longer available in the U.S., it is a single-dose, live attenuated vaccine containing a weakened version of the virus. Shingrix is a two-dose recombinant vaccine that shows the body only part of the VZV virus plus an adjuvant.

There is no specific-recommended interval of time that you should wait between Zostavax and Shingrix. However, the safety studies were conducted among people who were vaccinated with Zostavax 5 or more years prior to their Shingrix vaccination.

Because Zostavax immunity wanes with age, a shortened interval can be considered depending on the age of the person.

How well does the Shingrix vaccine work?

The Shingrix vaccine was recommended in 2017 by the Advisory Committee on Immunization Practices (ACIP) for adults 50 years of age and older. The committee expanded its recommendation in 2021 to adults over 18 years with weakened immune systems.

The Shingrix vaccine is 90% effective against shingles and post-herpetic neuralgia for approximately 7 years in healthy adults with no immune deficiency.

In post-licensure, real-world studies, Shingrix has demonstrated 86.8 percent protection in adults ages 50 to79 years and 80.3 percent in those aged 80 years and older.

Among Medicare beneficiaries, the vaccine was 70.1 percent among those with no immune compromise and 64.1% among those with immune compromise. The second dose did not appear to be less effective when administered more than 180 days after the first dose.

The vaccine offered high protection against post-herpetic neuralgia.

Why did Shingrix replace Zostavax?

A live attenuated vaccine (Zostavax; Merck) was licensed in 2006 for those at least 60 years of age. The vaccine is no longer available in the US since November 18, 2020. The CDC withdrew its recommendation for Zostavax because protection waned substantially with age. For example, among adults 70 to 79 years, Zostavax protection was 41% and for those over 80 years protection waned to 18%.

How safe is the Shingrix vaccine?

There are systemic side effects to Shingrix, including:

  • Fatigue. General tiredness and lack of energy;
  • Muscle pain. Aching and sore muscles;
  • Gastrointestinal symptoms. Issues in the digestive system such as cramping.

Side effects typically go away about 72 hours after vaccination. Medication for symptoms may be taken after vaccination if discomfort arises. The CDC generally advises against taking medication for pain before vaccination, as this may interfere with the vaccine’s effectiveness.

Fainting may occur following vaccination. Precautions should be taken following vaccination to avoid falling, such as sitting down for 15 minutes.

Is there a risk of Guillain-Barré Syndrome after Shingrix?

Guillain-Barré Syndrome (GBS) is an autoimmune condition where the body’s immune system damages nerve cells, causing weakness or paralysis. Most people fully recover, but permanent damage can occur.

The Food and Drug Association (FDA) routinely monitors safety using a variety of surveillance systems. On March 24, 2021, the agency issued an update on Shingrix after detecting an association between vaccination and GBS.

In the 42 days after Shingrix vaccination, the FDA found an excess risk of 6 cases per million first doses among adults aged 65 or older. The agency found no excess risk after the second dose.

While there appears to be an association between Shingrix vaccination and GBS, a causal relationship has not been established yet.

The risk of GBS is also increased after infection with a virus or bacteria. Between 3,000 to 6,000 people in the US develop GBS each year, and the risk increases with age.

I have not had chickenpox, do I still need the shingles vaccine?

If you have never had chickenpox or the varicella vaccine (which is a live attenuated virus vaccine) you are not at risk for shingles.

However, nearly everyone born before 1980 has had chickenpox, according to the CDC. This means that the virus is latent and could reactivate to cause shingles.

People who received the chickenpox vaccine are at lower risk for shingles than those who had the actual disease.

I have very high antibodies to chickenpox, do I still need a shingles' vaccine?

Antibodies are one component of the immune system—known as “humoral” immunity. The part that prevents shingles is the “cellular” component.

The cellular immune system is led by the T cells, which are on constant patrol looking for infected or precancerous cells. With age, our cellular immunity wanes. This is why the CDC recommends the Shingrix vaccine for everyone over 50 years.

I have shingles right now, if I get vaccinated will it go away?

The shingles' vaccine is not a treatment for shingles, and the CDC recommends waiting until your symptoms have passed before you get Shingrix. Similarly, if you have a moderate or severe illness, you should postpone vaccination.

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