Variants of the novel coronavirus are the biggest risk for the US economic recovery, Minneapolis Federal Reserve Bank President Neel Kashkari has said.
"The biggest risks that I see to the recovery are these variants," Kashkari told the Economic Club of New York, mentioning one variant of the virus which is dominant in parts of the US and easily infects younger people, Xinhua reported.
If organisations including daycare centres and schools need to be closed in response to the spread, that could "set us back", he said.
"That's not my basecase scenario but that's what the healthcare experts that I consult with are warning me about," he added.
Meanwhile, with two COVID-19 vaccines now under scrutiny for possible links to very rare cases of blood clots in the brain, U.S. government scientists are focusing on whether the specific technology behind the shots may be contributing to the risk, Reuters reported.
The U.S. Food and Drug Administration on Tuesday recommended temporarily halting use of the Johnson & Johnson vaccine after reports of six cases of CVST in women under age 50 among some 7 million people who received the shot in the United States.
In Europe, health regulators said last week there was a possible link between the AstraZeneca Plc vaccine and 169 cases of a rare brain blood clot known as cerebral venous sinus thrombosis (CVST), accompanied by a low blood platelet count, out of 34 million shots administered in the European Economic Area.
Both vaccines are based on a new technology using adenoviruses, which cause the common cold, that have been modified to essentially render them harmless. The viruses are employed as vectors to ferry instructions for human cells to make proteins found on the surface of the coronavirus, priming the immune system to make antibodies that fight off the actual virus.