Aug 21 (Reuters) - Dynavax Technologies ( DVAX ) said on

Thursday its experimental shingles vaccine generated a similar

immune response as GSK's blockbuster shot Shingrix,

while showing a better safety profile, in early-to-mid-stage

study.

Shingles, or herpes zosteris, is a viral infection

characterized by painful rashes that could lead to serious

complications such as long-term nerve pain and vision loss.

The disease is caused by the varicella-zoster virus, which

also causes chickenpox, and affects about 1 million Americans

each year, according to government data.

Dynavax ( DVAX ) tested two variants of its candidate, Z-1018, in the

trial of 92 people aged 50 through 69 years. All subjects

injected with either of the vaccine variants showed a similar

immune response to those given Shingrix, one month after the

second dose.

Meanwhile, 12.5% of people injected with the

experimental candidate had post-injection reactions such as

swelling and redness, lower than the 52.6% people who took GSK's

shot. No safety concerns have been identified in the study, the

company said.

As vaccines are given to healthy people, their safety

and tolerability can influence preferences.

The company said it plans to begin the second part of the

trial with one of the doses by the second half of the year in

adults 70 years of age and older.

The U.S. Food and Drug Administration had approved a

pre-filled syringe version of GSK's Shingrix last month.