The latest on the coronavirus pandemic and vaccines

Now is not the time to experiment with changing the two-dose schedule set for the Pfizer and Moderna Covid-19 vaccines, Dr. Nancy Messonnier, the director of the National Center for Immunization and Respiratory Diseases at the US Centers for Disease Control and Prevention, said in conversation with the Journal of the American Medical Association on Friday.

Outside factors such as emerging variants make it difficult to try and extend the time between doses right now, Messonnier said.

“For me right now, it’s the wrong moment to dial back. We’re looking at the science carefully,” Messonnier said, adding that this and other questions will be discussed Monday at a meeting of the CDC's vaccine advisers.

As the pandemic continues to impact the US, the major order of business for President Biden and Congress is to pass a $1.9 trillion Covid relief package before the round of unemployment benefits and other aid approved in December lapse, again leaving millions of Americans short of help.

What's riding on this negotiation is the $1,400 stimulus checks proposed by Biden even before he took office, as well as that extra federal unemployment money. Democrats have said they will get a bill signed by mid-March.

Here are three key things to know about the legislation proposed by House Democrats that will be voted on today:

But getting the proposal — proposals, really, since there will be different versions between the House, Senate and White House that must be reconciled — passed into law will test Biden's calls for unity.

House Majority Leader Steny Hoyer told reporters that “one or two” Democrats could vote against the Covid relief bill tonight, but is confident the bill will pass.

“I expect to have overwhelming Democratic support for it,” Hoyer said. “Expecting unanimity all the time is a little tougher.”

Democratic Rep. Kurt Schrader, who is the only remaining House Democrat who voted against the $15 minimum wage bill in 2019 that is still a member of Congress, told reporters he is “not so sure” he will be voting for the package tonight.

House Majority Whip Jim Clyburn told CNN’s Manu Raju that not all Democrats will vote for the bill tonight but it will pass. He said they can only afford to lose three votes.

More on the House relief package: Progressives have fought to include a minimum wage increase in the legislation, but that effort was dealt a major blow on Thursday when the Senate parliamentarian ruled against including the increase in the Covid relief bill, an aide familiar with the process and two sources with direct knowledge of the situation tell CNN.

As a result, when the House passes their bill with the increase included, the Senate is expected to have to strip the minimum wage provision out and then eventually, the bill would go back to the House and face another vote.

Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, on Friday said that countries making deals with Covid-19 vaccine manufacturers providing vaccines to COVAX are undermining the effort to vaccinate people around the world. 

Tedros did not name any countries making such deals.

COVAX is an entity run by a coalition that includes the Vaccine Alliance known as Gavi and the World Health Organization (WHO), and is funded by donations from governments, multilateral institutions and foundations.

Its mission is to buy coronavirus vaccines in bulk and send them to poorer nations that can't compete with wealthy countries in securing contracts with the major drug companies.

Two countries – Ghana and Côte d’Ivoire – have now received vaccine doses from COVAX and the Serum Institute of India, Tedros said, and more doses will go to more countries in the coming weeks. 

There’s progress toward the target of starting vaccination in all countries in the first 100 days of the year, “but that progress is fragile,” he said. 

He said that now is the time to do everything to scale up production, including licensing, technology transfer and intellectual property waivers, when necessary.

While Tedros said that he understood that governments have an obligation to protect their people, the best way to do it is to suppress the virus everywhere at once. 

Tedros said that the distribution of diagnostics, oxygen and dexamethasone also needs to be accelerated, as “although vaccines are a very powerful tool, they’re not the only tool.” 

The House of Representatives is expected to vote Friday evening to approve President Biden's $1.9 trillion pandemic aid package, a major step toward enacting the first legislative priority of the new administration as the devastating fallout from the spread of Covid-19 has left Americans in dire need of further relief.

The package advanced by House Democrats includes direct aid to small businesses, $1,400 direct checks to Americans making less than $75,000 annually, an increase in the child tax credit, direct funding to state and local governments, funding for schools and more money for vaccine distribution.

It is expected to pass on a party line vote as House Republicans have urged their members to vote against the package and are seeking to limit defections.

Republicans have argued that the legislation overreaches and serves as a liberal wish list of agenda items and complain that they have been locked out of the process for crafting the measure.

Democrats counter that they are willing to work with Republicans, but will not water down the plan and say they have a mandate to take sweeping action to address the pandemic now that they control Congress and the White House.

What happens next: If the bill passes in the House, it will then be up to the Senate, which is using the reconciliation process. The process allows lawmakers to bypass the 60-vote threshold typically required for breaking filibusters and moving legislation forward. Whatever version the Senate approves would also have to pass through the House.

Current expanded unemployment benefits run out March 14. That's the date by which Democrats have said they must have the Covid relief bill passed into law.

"We are on track to get this bill done and get it on the President's desk before the expiration of the enhanced unemployment benefits, which is March 14," Senate Majority Leader Chuck Schumer said Wednesday.

See full breakdown of what's in the most recent bill proposed in the House is here.

CNN's Zachary B. Wolf contributed reporting to this post.

About 70.5 million doses of Covid-19 vaccine have been administered in the United States, according to data published Friday by the US Centers for Disease Control and Prevention. 

The CDC reported that 70,454,064 total doses have been administered, about 75% of the 94,300,910 doses delivered. 

That’s about 2.2 million more administered doses reported since yesterday, for a seven-day average of nearly 1.6 million doses per day. 

More than 14% of the US population – more than 47 million people – have now received at least one dose of vaccine and nearly 7% of the population – about 22.6 million people – have been fully vaccinated with both shots, CDC data shows. 

Note: Data published by the CDC may be delayed, and doses may not have been given on the day reported. 

Nigeria expects to receive its first 4 million doses of Covid-19 vaccines next week from the global COVAX vaccine program, said Walter Kazadi Mulombo, the World Health Organization representative in Nigeria.

Mulombo on Friday added that Nigeria was expecting 14 million doses of the Oxford-AstraZeneca vaccine in total.

“WHO more recently supported the country to develop its vaccine deployment and vaccination plan for Covid-19," Mulombo told journalists in a virtual briefing. "It has been used to secure through the COVAX Facility close to 14 million doses of the AstraZeneca vaccine and four million of which are expected next week."

The situation in Nigeria was so far much better than had been widely predicted early in the outbreak, said Chikwe Ihekweazu, director general of the Nigeria Centre for Disease Control.

Nigeria, Africa's most populous country with some 200 million people, has reported fewer than 1,900 Covid-19 deaths so far, according to government data.

The COVAX initiative is led jointly by WHO, Gavi, the Coalition for Epidemic Preparedness Innovations (CEPI) and UNICEF, which is leading vaccine procurement and delivery operations. So far this week, the COVAX initiative has delivered vaccines to Ghana and Ivory Coast. 

Health Canada announced Friday it has authorized AstraZeneca’s Covid-19 vaccines for use.

The authorization of the AstraZeneca vaccine developed with Oxford University and the Serum Institute of India’s version of the AstraZeneca vaccine introduce the first viral vector-based Covid-19 vaccines, and the third and fourth authorized Covid-19 vaccines in Canada. 

The Pfizer/BioNTech and Moderna Covid-19 vaccines are already authorized for use in Canada.

Health Canada received an application for authorization from AstraZeneca on Oct. 1 and Serum Institute of India on Jan. 23. The authorization of the Serum Institute of India’s vaccine depended on the clinical trial results’ comparability to that of AstraZeneca’s vaccine, Supriya Sharma, Health Canada’s chief medical adviser, said at a news conference Friday. 

Health Canada, which has been reviewing the Johnson & Johnson vaccine since Nov. 30, is expecting additional information from Janssen Pharmaceuticals, specifically on manufacturing, later today, she said.

“[An authorization of the J&J vaccine] can go quite quickly if that information is all in order,” Sharma responded when asked if an authorization from Health Canada will promptly follow the US Food and Drug Administration’s anticipated emergency use authorization. 

The Novavax Covid-19 vaccine, which was submitted for review on Jan. 29, is currently undergoing a Phase 3 clinical trial, Sharma said. Health Canada expects the results from the trial at the beginning of April.  

“We are expecting to reach a regulatory decision on these vaccines on a similar timeline to other international regulators, such as the US Food and Drug Administration and the European Medicines Agency,” Sharma said. “This is all very promising news.” 

Johnson & Johnson’s coronavirus vaccine “checks nearly all the boxes” on a list of what’s needed in a coronavirus vaccine, Dr. Greg Poland, head of the Mayo Clinic's Vaccine Research Group, said Friday.

The Johnson & Johnson vaccine is safe and effective, and has the advantage of being a single-dose vaccine that has no special storage requirements, Poland told a meeting of vaccine advisers to the US Food and Drug Administration.

“The Janssen vaccine candidate checks nearly all the boxes.” 

The FDA’s Vaccine and Related Biological Products Advisory Committee (VRBPAC) is meeting to discuss the vaccine and will vote later Friday on whether to recommend FDA emergency use authorization. The FDA almost always follows the committee’s recommendations.

“There are only three ways the pandemic can be controlled,” Poland told the committee. “First is a hard lockdown,” with universal masking and social distancing, he said. “Second, the virus mutates to be less transmissible,” he added – but noted that more transmissible variants are already emerging and spreading.

Third is vaccination. “Vaccines are our primary weapons in countering and controlling this threat,” Poland said.

He noted the vaccine made by Johnson & Johnson’s Janssen division was studied in multiple countries when the virus was spreading fast – and when new variants were circulating.

The Johnson & Johnson vaccine, which, if authorized, would be the third to be OK’d for the US, provided 85% protection against severe disease and the need for hospitalized in advanced, Phase 3 clinical trials.