Moderna Inc. shares declined as the company’s cost-cutting efforts failed to assuage investors who are worried about the decline of its COVID vaccine business.

The layoffs are part of an ongoing effort to reduce operating costs amid government and competitive challenges to its vaccine business.

In a note to employees Thursday, Moderna Inc. said it was laying off about 10% of its global workforce as part of the biotechnology company’s plan to cut annual costs by $1.5 billion over the next couple of years.