The first vaccine to prevent shingles, Merck’s Zostavax, has been approved in both the USA and Europe for adults aged 60 or more. Shingles develops when the virus that causes chickenpox, varicella-zoster, is reactivated. After a childhood bout of chicken pox, the virus lays dormant for many years, ready to come into action when the carrier’s immune system weakens, either through age or illness.

Anyone who has ever had chicken pox is susceptible to developing shingles later on in life. 90% of humans get chicken pox. Of the approximately one million people in the USA who get shingles each year, nearly half are over 60.

There are 50 million Americans over the age of 60.

According to data so far, the vaccine offers protection for at least four years. Some wonder whether it may just postpone shingles, rather than prevent it completely. Merck has to conduct a long-term follow-up study.

Merck had applied for the vaccine to be approved for 50 year olds. However, the company had no data on the vaccine’s performance for people under 60. So, the FDA set the minimum age at 60.

Dr. J Goodman, FDA, said Zostavax is a booster vaccine. It boosts an older person’s immune system against the virus from re-emerging and causing shingles.

The single dose vaccine will be on the market soon at $145.35 in the USA.

After going through a bad period with Vioxx, this has been a good month for Merck. Last week an FDA advisory panel recommended that its HPV vaccine, which protects women from developing cervical cancer, be approved by the FDA. The FDA usually follows the advice of the panel.

Zostavax is estimated to bring in nearly $1 billion’s worth of revenue for Merck per year by the end of this decade.

As many children are vaccinated for chicken pox these days, it is not clear what the long-term future role of a shingles vaccine may be.

The vaccine will not be used for people who have had or now have shingles. Neither will people with weakened immune systems nor HIV patients get the vaccines.

A study indicated a small elevated risk of cardiovascular problems following the vaccine. Side effects can include itching, headache and pain from the injection.

Written by: Christian Nordqvist
Editor: Medical News Today