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Zostavax Lawsuit Attorney

Zostavax was developed to prevent the outbreak of shingles (herpes zoster) in adults 50 and older.

woman itching because of shingles

Shingles is caused by the reactivation of the chickenpox virus (varicella zoster) due largely to stress. The symptoms of shingles include severe pain, discomfort, and a rash across the body. People who suffer from shingles experience a severely decreased quality of life.

Merck is the developer, designer, and manufacturer of Zostavax. The pharmaceutical giant is responsible for the licensing, labelling, testing, distribution, marketing, and sale of Zostavax. They have a duty under the law to warn people about the dangers of taking their vaccine.

As of March 2018, the CDC has updated the vaccine information sheet to add a warning of the potential risk of viral infection with Zostavax.

If you or someone you know has been affected after receiving Zostavax contact us to discuss your case. Learn more about Zostavax.

Merck’s Varicella Zoster Virus Can Damage the Brain, Nervous System

The design of Merck’s Zostavax was based entirely on its chickenpox vaccine, Varivax. They are the exact same product. The only difference is that Zostavax contains more live varicella zoster virus in each injection. The virus is attenuated, meaning it is designed to activate the recipient’s immune system without the risk of them contracting the disease. However, when a virus is under-attenuated it is more dangerous. For this reason, those who receive Zostavax have a higher risk of developing the disease or reactivating the latent virus. That is why people with weakened immune systems should not receive vaccines containing an attenuated live virus like Zostavax.

Merck has added several adverse effects to the package label of their weaker vaccine Varivax since 2006. Most of these reactions to Varivax are related to the nervous system including Bell’s palsy, stroke, encephalitis, GBS, and several others. Varivax is the weaker version of Zostavax and is known to have dangerous side effects. Zostavax has been found to contain over fourteen times more virus by volume than Varivax. It is no surprise that injecting elderly people with a large amount of live virus could cause injuries like shingles, encephalitis, and stroke. For further information on the effects and injuries follow these links. 1 2 3

Shingrix as a Safer, More Effective Alternative to Zostavax

Luckily in October 2017, the FDA approved Shingrix an alternative shingles vaccine manufactured by GlaxoSmithKline. This new drug was proven safe and effective in over 90% of cases. Compare Shingrix’s efficacy to Zostavax, which some studies showed that the vaccine was only effective in preventing shingles 18% of the time. For further information on Shingrix follow this link. Zostavax had as low as an 18% success rate in certain age groups. Since the finding and successful application of Shingrix, Merck has not created a vaccine utilizing a similar design.

Zostavax Vaccine Injury Posts

Zostavax Lawsuit Attorney

Varicella Zoster Virus

Chickenpox is an illness that commonly occurs in children. This virus that causes chickenpox is known as varicella zoster. After it has run its course, the virus remains dormant for many years hidden in nerve cells. When varicella zoster is reactivated, it is known as shingles (herpes zoster). Shingles and chickenpox are directly related to the same virus.

The chickenpox virus can reemerge and replicate in healthy nerve cells, it then bursts and attacks more cells. It makes its way down the fiber of the nerves to areas of the skin. This causes the widely known itchy and painful skin rash associated with shingles.

Dangers of the Virus

The older you are the more serious shingles can become. The risk of death when the virus affects an older person, which accounts for a smaller percentage of cases, is higher. In older adults, stress is thought to be the biggest contributor to the virus’ reactivation. Over the course of two to three days, this infection spreads and can manifest in a rash all over the body.

Blood clots are a severe problem that arise when the varicella-zoster virus is not treated. These clots are located in the nervous system and can lead to strokes. Inflammation and encephalitis can also be a risk of the varicella zoster virus. Other symptoms of the varicella-zoster virus are muscle tone gain or loss, ataxia (trouble walking), hemiparesis which is a weakness on one side of the body, and several others.


The varicella zoster virus can be treated with anti-viral medication, such as Acyclovir or Valtrex. Such medications were developed to combat the active infection once it has reemerged. Shingrix is an effective vaccine that has a 90% success rate of preventing shingles. It is safer and more effective than attenuated vaccines, such as Zostavax, that does not accomplish this task.


With Zostavax’s lack of efficacy, there was room for another vaccine to be developed. In October of 2017, a new shingles vaccine was FDA approved. Shingrix, picked up where Zostavax had failed to prevent cases of shingles (herpes zoster) in older adults.

Trailing Behind

Zostavax utilized a living mutated strain of thee varicella-zoster virus. The Zostavax vaccine has the added risk of infecting a person intending to be vaccinated, or could potentially activate the dormant virus already inside the body. This is what has happened in cases where patients had received the Zostavax vaccine, causing numerous side effects.

After a decade of Zostavax, it is almost non-existent in most markets. Shingrix has destroyed Zostavax market share and caused most hospitals to drop it from use. This ultimately led to the CDC actively discouraging Zostavax and promoting Shingrix. The Shingrix label states that it can be used whether or not you have had a previous case of herpes zoster, and also can be taken even if you have had a prior dose of Zostavax.

After all this information had been collected, Zostavax has still neglected to consider changing their vaccine to a product more aligned with the type of vaccine that Shingrix has proven to be.

Merck & the Shingles Prevention Study

woman studying virus in a microscope

Merck’s key clinical trial for Zostavax was meant to show the safety and effectiveness of their vaccine for the public. Known as the Shingles Prevention Study (SPS), this clinical trial had serious problems.

The Flaws of the Study and Merck

The FDA had several concerns about the safety and effectiveness of Zostavax. Dr. Overturf on the advisory committee for the FDA cited that Zostavax should require active surveillance of the people receiving the vaccine. Overturf also stated that there wasn’t enough safety data to consider giving this vaccine to the whole population.

This trial was labeled Protocol 004, also known as, Shingles Prevention Study. This study ran from November 1998 until April 2004. The SPS had many errors that included modified definitions, study endpoints, scoring criteria, and other protocols. The study found that Zostavax was only 51% effective in lowering the incidence of herpes zoster rash. Other injuries were not documented in the trial notes and they only studied patients for a limited time. The list of other potential injuries includes neurological diseases, brain inflammation, developing shingles and several others.

Though the SPS had many criticisms and mistakes, Merck’s product was released anyway in 2006. Merck performed three post-marketing studies, and each one was flawed.

Despite the strong evidence against Zostavax, Merck has failed to properly address patients and medical provider’s problems. Zostavax contains fourteen times more of the virus than Merck’s chickenpox vaccine Varivax. It is an attenuated vaccine which uses a subdued virus to try to prevent the disease. Merck had considered not using a live virus, but decided against it so they could launch their vaccine earlier. Long-term effects of attenuated vaccines are still unknown.


When varicella zoster virus reemerges, it destroys cells as it travels across the nervous system. Over the course of two to three days, the infection spreads to the skin causing the shingles rash. This rash can appear along the arms, head, face, torso, and legs. The shingles rash can be very itchy and painful.

Zostavax Causing Brain Injuries

Zostavax utilizes a live strain of the virus to stimulate the immune system and try to prevent an outbreak. The risk of this type of virus referred to as an attenuated virus, is that there is a potential for it to infect the host or activate the dormant virus. In the case of Zostavax, while it has shown to reduce the rash associated with shingles, it can cause the same injuries it was manufactured to prevent. Encephalitis and inflammation of the brain are side effects that cause concern.

Encephalitis is a severe injury associated with Zostavax. Encephalitis is caused by an immune system response to the infection. This causes the body to incorrectly attack its own healthy cells in the brain and spinal cord instead of the virus harming it. This is also called secondary encephalitis. Acute Disseminated Encephalomyelitis is a commonly known secondary encephalitis associated with this brain infection from the varicella-zoster virus.

Varicella-zoster virus is neuro-virulent and neurotropic. This means that this VZV has the capacity to attack the nervous system, does so directly, and is the most common form of brain infection. The herpes zoster virus is carried along the nerves to the brain. Inflammation occurs in the brain leading to serious neurological problems. Those who don’t show a rash, have immune systems that are at a high risk for complications. Most medical professionals have no way to diagnose an infection without identifying a link between varicella-zoster and a failed vaccination.


Merck’s Zostavax vaccine contains the live varicella-zoster virus that can cause chickenpox and shingles in people who receive the vaccine. Zostavax is linked to causing the same side effects that it was aimed to prevent.

Zostavax Causing Clots

The varicella-zoster virus is a strain that is known to cause chickenpox in children, and the dormant virus can activate in older adults causing what is commonly known as shingles (herpes zoster). When the virus activates again and travels through the brain, and the nervous system, it can cause many issues along the way. Besides common symptoms of an itchy painful rash and other critical brain injuries, those infected with varicella zoster can also develop a stroke.

Varicella-zoster can spread along the nerve fibers causing blood diseases. These blood disorders lead to clots forming. Strokes are caused when clots travel along blood vessels of the brain. It is here where these blood clots cause the most damage to an individual. These clots block the blood supply to the brain. Varicella-zoster can also cause the body to attack blood vessels causing a rupture.

These clots can swell and cause the vessels to rupture at locations in the brain. When one of these vessels is rupture impeding blood flow, this can cause a person to have a stroke. Stroke is described as when blood flow to a specific region of the brain is interrupted. Depending on the location of the stroke, the symptoms could vary from sensation loss to seizures.

Shingles patients are over 60% more likely to have a stroke than people without. There is a higher risk of stroke when a shingles rash is closer to the head, with a rash near the eyes being most dangerous, and the chances decrease over time after an outbreak.

Other Injuries

woman having muscle pain

Zostavax was designed to prevent the reactivation of varicella-zoster and the painful rash associated with it. Zostavax is known to cause severe debilitating injuries attack muscles, the brain, motor functions, and can even cause shingles.

Risks Linked to Zostavax

Zostavax can diminish the rash that is associated with the shingles virus (herpes zoster) but can cause other effects to occur. These other issues cause several compounding problems inside the body.

Ataxia is one way that Zostavax attacks the body of those who are vaccinated. This causes the person who received the vaccine to have trouble walking and impedes performing daily tasks. Other symptoms associated are muscle tone gain and loss, as well as joint pain. Zostavax is known to cause people to develop weakness on one side of their body, debilitating half of their motor function. Guillain-Barre syndrome is another injury related to Zostavax as well. This autoimmune disease can develop as a tingling sensation, progress to muscle weakness, and can escalate into paralysis.

Zostavax can also cause cases of Bell’s palsy, seizures, and dizziness to occur. Bell’s palsy is often linked to a viral infection attacking nerves in the head and face. Signs of Bell’s palsy are drooping eyes, mouth, face, and headaches. Seizures are also linked and attack the systems of a vaccinated person. These sudden electrical interferences in the brain can cause mood changes and loss of consciousness. They are uncontrolled and can only be diagnosed after imaging is done.

Zostavax has failed in numerous ways to prevent any effects from the shingles virus and actually cause the disease it was meant to prevent.



Principal & Founder
This article was written by Mark Sadaka, a seasoned trial lawyer in nationally significant cases. He fearlessly champions clients impacted by fatal or severe injuries caused by others or corporations. Renowned for his expertise in complex litigation, he's featured in books, sought after by media for interviews, and a highly sought speaker. Notably, he exclusively represents individuals facing life-changing injuries or substantial financial losses.

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