Drugmaker Merck & Co said on Monday that they would be ending their vaccine program due to inferior immune responses.
Two vaccines in development from Merck showed immune responses below the level of those seen in patients who had recovered from COVID-19, as well as those of competitors vaccines.
The announcement is a setback to the fight against the pandemic, and comes a month after Sanofi and GlaxoSmithKline announced the delay to their vaccines until late this year.
So far Pfizer and German-partner BioNTech along with Moderna have produced shots going into arms, with Johnson & Johnson, AstraZeneca, and others continuing to develop vaccines.
Merck said while foregoing the vaccine development, there are two investigational medicines they will focus their efforts on — MK-7110 and MK-4482, which it now calls molnupiravir, an oral antiviral.
More details at Reuters.