Merck announced Tuesday that it will spend $15 million renovating and expanding its facility in Wilson.

The capital projects, which include overhauling existing manufacturing space and adding a cold storage facility for vaccine packaging, will not increase the company’s workforce at the site. Merck employs about 400 people at its 225-acre packaging center in Wilson, which opened in 1983.

Most of the Merck pharmaceutical products now packaged in Wilson are done so at room temperature.

Vaccines, which are a growing part of Merck’s business, require expansive cold storage space.

Merck has a vaccine plant in Durham that is poised to become the largest live-vaccine production facility in the world.

The rapidly growing lab, which makes chicken pox vaccine, employs about 850 and could expand to 1,000 workers at full production.

By 2013 Merck expects to be making at the Durham facility at least four vaccines for shingles, measles, mumps and rubella.

Staff writer David Bracken

Bracken: 919-829-4548