South Korean drug regulators on Monday granted sales approval to SK Chemicals’ herpes zoster vaccine, marking the second ever approval by a country’s regulator of a new treatment targeting the viral disease.

The Korean Ministry of Food and Drug Safety approved SK’s Sky Zoster vaccine for use in adults aged 50 and over. It is the second vaccine for herpes zoster to be commercialized globally next to US-based Merck & Co.’s Zostavax approved in 2006.

Herpes zoster, also known as shingles, is a viral disease characterized by a painful blistering skin rash that develops on the body as a result of a reactivation of the varicella zoster virus, the same virus that causes chicken pox. A shingles outbreak is also known to invoke nerve pain, or postherpetic neuralgia, at times.

SK Chemicals developed Sky Zoster as an inactivated vaccine, a vaccine that consists of virus particles and bacteria that have been grown in a culture and then killed, making them more stable and safer than live attenuated vaccines.

The Korean drugmaker said it plans to begin commercial production of its shingles vaccine, with the aim of supplying it to Korean hospitals this year. Leveraging its local approval success, SK also plans to bring its shingles vaccine to global markets in the future, it said.

Korea’s shingles vaccine market now stands at around 80 billion won ($69.78 million), according to SK Chemicals. On the other hand, the global shingles vaccine market reached $685 million last year, according to market research firm Datamonitor.

Globally, UK-based GlaxoSmithKline is far ahead of SK Chemicals in the race to commercialize a new shingles vaccine rivaling that of Merck & Co, also known as MSD outside the US.

GSK is expected to soon score the US Food and Drug Administration’s approval of its own shingles vaccine Shingrix, as the US FDA’s advisory panel voted 11-0 for approving the drug last month.

Once approved and commercialized, Shingrix is expected to eat into the sales of MSD’s Zostavax, which are expected to reach around $730 million this year, according to market forecasts.

By Sohn Ji-young (jys@heraldcorp.com)