What you need to know:

• The US reported a record high of more than 4,300 new Covid-19 deaths, as all air travelers to the country will need to show a negative virus test from Jan. 26.
• The Chinese-made Sinovac Covid-19 vaccine was just 50.38% effective in late-stage trials in Brazil, significantly lower than earlier results showed.
• Japan has banned foreign nationals from entering the country and put seven further regions under a state of emergency.
• England is considering putting Covid patients in hotels, as a study reveals deep trauma among ICU workers.

Moderna CEO Stephane Bancel said Wednesday he does not believe variants of coronavirus that have been detected in the UK, South Africa, or Brazil, and now seen in many countries, will affect the efficacy of his company’s vaccine.

“I think the question is more medium-term as the virus continues evolving over time,” Bancel said Wednesday during the annual JP Morgan Health Conference.

“I’m not worried for the short term but we are watching that very closely because I think that we might be moving into a world where we need new strains of vaccine down the road — but not in the short term,” he said.

Pfizer President Angela Hwang said she is “bullish” about what the Pfizer vaccine is capable of doing in terms of reacting to mutations and variants, but they are watching it closely as well. “What we have to realize is the virus could change and we may need a new vaccine altogether,” Hwang said.

Hwang said Pfizer is ready should the virus change and “that’s where the beauty of the mRNA technology comes in.”

“With the sequence, we are going to be able to make a new vaccine in very short order, in as little as six weeks,” Hwang said.