Michigan and Washington are the latest US states to bring in strict measures to try and curb the spread of Covid-19.
High schools and colleges are to halt on-site teaching and restaurants are prohibited from offering indoor dining in Michigan from Wednesday.
Indoor restaurant dining is also banned in Washington State, and gyms, cinemas, theatres and museums will close.
On average, more than 1,000 people a day are dying with the virus, and the overall death toll is close to 250,000.
The Trump administration struck an optimistic note on Friday, saying it hoped to distribute 20 million doses of an approved vaccine in December, and for each month after that – although vaccines have yet to get official approval.
But aides to President-elect Joe Biden say the White House’s refusal to facilitate a presidential transition means his team is being excluded from planning around a vaccination campaign that will be a priority for Mr. Biden when he takes office in January.
“Our experts need to talk to those people as soon as possible so nothing drops in this change of power we’re going to have on January 20th,” the president-elect’s chief of staff Ron Klain was quoted as saying by the Associated Press news agency.
Mr. Klain said the Biden team would nonetheless start talking to vaccine manufacturers, including Pfizer.