WAVRE, Belgium, Nov 15 (Reuters) - GlaxoSmithKline said further growth from its shingles vaccine, which has boosted earnings, would be reined in by limited capacity until 2024, but a new bioreactor facility would then be ready to bring a "step change" in production.
GSK, Britain's largest drugmaker, had originally envisaged a gradual launch in the United States, its biggest market, but regulators unexpectedly recommended Shingrix not only for people reaching the age of 50 but also to replace an established product.
A bioreactor in Belgium that makes so-called antigens - proteins that trigger an immune reaction against the shingles virus - is reaching its capacity limits. A second one is in the works at an undisclosed location, but the complex facility takes time to build.
"The key project is the expansion of antigen bulk production which will come online in 2024. That will be what will create the next step change in our capacity," said Roger Connor, president of GSK's vaccines business.
Until then GSK is working on more than 20 other projects to eke out higher production, aiming to increase the number of Shingrix doses to a "high teens of millions" in 2019.
In 2024 "you'll see tens of millions of increase, rather than single digit millions," Connor added.
($1 = 0.7815 pounds) (Reporting by Ludwig Burger; Editing by Mark Potter)