The antibody cocktail given to Donald Trump when he was struck down with COVID-19 last year appears to lose some effectiveness when faced with the heavily mutated Omicron variant. The Wall Street Journal first reported on the results of preliminary tests from drugmaker Regeneron that appear to show a faded effectiveness of its antibody treatment against Omicron when compared to earlier mutations. However, Regeneron said it won’t be able to say exactly how big of an impact the variant has on its treatment until further testing is carried out in the next few weeks. Dr. George Yancopoulos, Regeneron’s president, said the company is already testing alternative antibodies that could tackle Omicron if it is proven to cause a significant loss of efficacy. “What we have to admit is, in the course of the past six days, our urgency has increased,” Yancopoulos told the newspaper. “What started out as a backup plan has now been made a lot more urgent.” Antibody cocktails are the only drugs that have been authorized to treat patients infected with COVID-19.