US-based vaccine development company Novavax Inc (NASDAQ:NVAX) has extended its timeline for reaching a production target of 150 million COVID-19 vaccine doses per month until the third quarter of 2021, because of a shortage of supplies including bioreactor bags and filters, Reuters news agency reported on Tuesday.

Novavax had previously expected to deliver full-scale vaccine production by May or June this year, but has revised this to the third quarter.

The company said it expects to receive UK regulatory authorisation for its vaccine as early as this month, after releasing impressive UK trial data. Clearance in the US is anticipated to be received as early as May, following a review by regulators of soon-to-be released data from its US vaccine trial.

According to Reuters, data released in March from the UK trial showed the Novavax vaccine to be highly effective against the original strain of the novel coronavirus as well as the more contagious and deadly variant first discovered in the UK. The vaccine may also provide some protection against a highly concerning variant that emerged in South Africa, which some drugmakers have said may require a booster shot to address.