September 15, 2016  Print

An international clinical trial of an experimental herpes zoster (shingles) vaccine has shown it is highly effective in preventing the disease amongst people over the age of 70.

An international clinical trial of an experimental herpes zoster (shingles) vaccine has shown it is highly effective in preventing the disease amongst people over the age of 70.

The trial results, which have been published in the New England Journal of Medicine, also show the vaccine prevents a common and feared complication of herpes zoster - prolonged pain from post-herpetic neuralgia. 

The paper’s first author, Executive Director of the Westmead Institute for Medical Research, Professor Tony Cunningham, said overall vaccine efficacy against herpes zoster in adults 70 and older was 90%.

There were no differences in vaccine efficacy between those who were 80 and older and those who were younger.

“The herpes zoster vaccine proved to be highly efficacious amongst the age groups most affected by the disease,” said Professor Cunningham,

“The 90 per cent result is actually better than any other vaccine commonly used in older patients and the result has specific implications for ultimately preventing the disease.

“This is important because in addition to causing great pain and severely impacting quality of life, shingles can result in significant morbidity.”

The trial was conducted in 22 countries including Australia and involved 14,816 participants with a mean age of 75.6 years. More than 22 % were over 80 years old.

Each participant was given two intramuscular doses of the vaccine – or a placebo – three months apart.

The most commonly reported local adverse reaction was pain at the injection site and the most frequently reported systemic adverse reaction was fatigue. The majority of injection site and systemic reactions occurred within seven days of vaccination, with most lasting 1-3 days, and generally were mild-to-moderate in intensity.

During a follow-up after a mean average of 3.7 years there were 223 cases of herpes zoster in the placebo group but just 23 cases in the vaccine group – an overall outcome of vaccine efficacy of 90%.

The results of the over-70s trial is in line with the results of trial of the vaccine on people over 50, which was presented and published last year and showed a 97% efficacy.

Professor Cunningham, who was also the chief investigator of the trial in Australia, said the results had broader implications for the design of adult vaccines.

“This vaccine contains the AS01b adjuvant system and the results indicate that the natural decline in immune responses with age can be overcome with the use of appropriate immune stimulants or adjuvants in a vaccine,” he said.

He said further trials will now be necessary to determine the duration of the vaccines’ efficacy beyond three years post-immunisation.