US president Donald Trump has doubled down on claims a vaccine for Covid-19 would be available amost half a year earlier than the US health authority predicts, while the CDC has changed its guidance again, after disagreement about testing criteria.

At a news conference the US president said historic progress had been made with three vaccines in the final stages of development, and he expects vaccines to be available for about a third of the country before the end of the year, the BBC reported.

“We’ll have manufactured at least 100 million vaccine doses before the end of the year, and likely much more than that,” he said.

“Hundreds of millions of doses will be available each month and we expect to have enough vaccines for every American by April.”

There are now about 330 million people living in the US, the country’s Census Bureau said in July.

Earlier this week

On Wednesday Trump also said at least 100 million vaccine doses could be distributed by the end of 2020, contradicting one of his top government health officials, who Trump dismissed as confused.

Hours earlier, Robert Redfield, director of the federal Centers for Disease Control and Prevention (CDC), said a Covid-19 vaccine could be broadly rolled out by the middle of next year or a little later.

Centers for Disease Control and Prevention Director Dr. Robert Redfield speaks during a Senate Appropriations subcommittee hearing, on 16 September.

Centers for Disease Control and Prevention Director Dr. Robert Redfield speaks during a Senate Appropriations subcommittee hearing, on 16 September. Photo: AFP

“No I think he made a mistake when he said that,” Trump said, telling reporters he called Redfield.

“That’s incorrect information. “I believe he was confused. I think he just misunderstood the question, probably.”

Redfield, head of the federal government’s disease control agency, made his comments in testimony before a US Senate panel.

He said general availability of a vaccine could come by “late second quarter, third quarter 2021.”

A vaccine could be ready as soon as this November or December, Redfield said, adding that limited first doses could go to those who were most vulnerable. But “in order to have enough of us immunized to have immunity, I think it’s going to take six to nine months,” he added.

US health chiefs reverse advice on testing, again

The Trump administration has reversed guidance on Covid-19 testing for a second time, urging those exposed to people with the virus to get tested even if they are not displaying symptoms.

The CDC sparked widespread outcry among state public health officials and experts in late August when it said that people who do not have symptoms may not need to get tested.

Before 24 August the CDC had encouraged testing for all those who were exposed. Friday’s latest guidance update effectively returns the CDC’s testing guidance to what it said before it was altered in late August.

Reuters reported that a majority of US states rejected the CDC’s 24 August guidance in an extraordinary rebuke of the nation’s top agency for disease prevention.

The change was made on a page aimed at health workers.

“The return to a science-based approach to testing guidance from the Centers for Disease Control and Prevention is good news for public health and for our united fight against this pandemic,” said Thomas File, president of the Infectious Diseases Society of America, in a statement.

Some state officials last month said they thought the administration’s choice to play down the importance of testing reflected a desire by Trump to cut the tally of new cases.

Trump, who is running for re-election on 3 November, told a rally in June testing is a “double-edged” sword because it leads to more cases being discovered, causing the United States to appear worse off than it would otherwise.

He added that he urged officials to “slow the testing down, please.” A White House official at the time told Reuters that the remark was a joke. However Trump contradicted that explanation, saying he was not joking.

Trump administration officials denied that the move was political and told Reuters that it reflected “current evidence and best public health practices.”

-BBC/ Reuters