New shingles vaccine gets FDA panel votes

By Dr. Ananya Mandal, MDSep 14 2017

On the 13th of September 2017, a U.S. Food and Drug Administration (FDA) advisory panel has voted 11 to 0 approving a shingles vaccine for its use in adults aged 50 and over. The panel unanimously accepted the safety and efficacy of the vaccine and thus GlaxoSmithKline’s Shingrix is on its way to FDA approval.

The members of the panel were apparently very impressed with the data provided by GSK on the effectiveness and safety of the vaccine from the clinical trials. The present vaccine available is Zostavax, which is the only vaccine against shingles in the market, manufactured by Merck & Co. Shingrix in a significant improvement over Zostavax, the panel found.

As the next step the FDA might consider the findings of the panel and its recommendations in its decision to approve the new vaccine. This is not mandatory but with the current levels of enthusiasm there is hope that the FDA would approve the vaccine in the coming weeks.

Shingrix is considered one of the more important products of GSK with high hopes riding on its back. It contains a component that can help improve its effectiveness. This component is made by Agenus Inc which would get the royalties from GSK for this component from its future sales.

Shingrix has been compared to Zostavax among older participants in clinical trials. Studies have shown that four years after an injection of Shingrix, the efficacy of the vaccine remained at 90 percent in persons over the age of 70 years compared to the efficacy of Zostavax which fails to remain effective after a few years.

Thomas Breuer, chief medical officer of GSK Vaccines, said in an interview that the age related decline in the protection against shingles is something this new vaccine is fighting and has overcome. The vaccine Shingrix is to be administered in two doses, two months apart. Apart from preventing shingles, it also reduces the risk of getting nerve damage and pain that follows an episode of shingles called postherpetic neuralgia.

The trials that helped Shingrix score with the panel of advisors are two major Phase III studies involving more than 29,000 subjects. There were little serious adverse effects with the vaccine and some instances of gout and stroke were questioned by the panellists. GSK assured that these instances were not due to the vaccine and has proposed more extensive post marketing safety studies to look into the instances of these conditions among the vaccinated individuals. Another issue raised by panellists was the fact that most of the participants in the studies were white and other ethnicities need to be represented in the studies.

Shingrix at present is also waiting for approval in other nations including Europe, Japan, Australia and Canada.

Shingles

Shingles or herpes zoster is a painful and blistering rash that usually affects older individuals and those with a lowered immunity. It can also affect younger individuals when they are ill or under stress.

Shingles or herpes zoster is actually a reactivation of the varicella-zoster virus that had caused a chicken pox infection in the person previously. The varicella zoster virus usually remains dormant in a person’s body and in times of weakened immunity such as in old age or during disease, the virus resurfaces as the painful blisters.

The blisters usually cluster in one place on one side of the body leading to burning, tingling or numbing pain. This gets dry and forms crusts over 2 to 3 weeks. The rash affects one side of the torso or may appear over face, forehead, eyes, mouth, and ears on one side. It typically follows distribution and branches of a nerve. Facial shingles is called Ramsay Hunt Syndrome.

Diagnosis is usually made by clinical examination and history of previous chicken pox infection. For treatment antivirals are prescribed and treatment needs to be started within 24 hours of feeling pain or burning. This can reduce the intensity. Cold compresses, soothing lotions, pain relievers etc. are prescribed for local pain.

In most cases the condition goes away by itself in 2 to 3 weeks and does not recur. Sometimes the nerve pain may persist. This is called Post herpetic neuralgia. When shingles affects the eyes or ears, it can leave a person blind or deaf.