A total of 30,000 planned volunteers are ready to take Covid-19 vaccine created by the U.S. government -- one of several candidates in the final stretch of the global vaccine race.

The world’s biggest COVID-19 vaccine study got underway on Monday.

However, there’s still no guarantee that the experimental vaccine, developed by the National Institutes of Health and Moderna Inc., will really protect, reports AP.

After two doses, scientists will closely track which group experiences more infections as they go about their daily routines, especially in areas where the virus still is spreading unchecked, the report says.

NIH’s Dr. Anthony Fauci said “Unfortunately for the United States of America, we’ve plenty of infections right now.”

Moderna Inc. said the vaccination was done in Savannah, Georgia, the first site to get underway among more than seven dozen trial sites in the country.

Meanwhile, several other vaccines made by China and by Britain’s Oxford University earlier this month began smaller final-stage tests in Brazil and other hard-hit countries.

Every month through fall, the government-funded COVID-19 Prevention Network will roll out a new study of a leading candidate -- each one with 30,000 newly recruited volunteers.

The report also said that the massive studies aren’t just to test if the shots work — they’re needed to check each potential vaccine’s safety and following the same study rules will let scientists eventually compare all the shots.

In August, the final study of the Oxford shot begins, followed by plans to test a candidate from Johnson & Johnson in September and Novavax in October.

Meanwhile, Pfizer Inc. plans its own 30,000-person study this summer.

In recent weeks, more than 150,000 Americans filled out an online registry signaling interest, said Dr Larry Corey, a virologist with the Fred Hutchinson Cancer Research Institute in Seattle.

Corey at a vaccine meeting last week said “These trials need to be multigenerational, they need to be multiethnic, they need to reflect the diversity of the United States population.”

He underscored that it’s especially important to ensure enough Black and Hispanic participants as those populations are hard-hit by COVID-19.

Usually, it takes years to create a new vaccine from scratch, but scientists are setting speed records this time around, spurred by knowledge that vaccination is the world’s best hope against the pandemic.

New Jersey police found 17 bodies in one of the state's largest nursing homes after an anonymous tip said a body was being stored in a shed.

A total of 68 people associated with the Andover Subacute and Rehabilitation centres have recently died, with 26 having tested positive for Covid-19.

Police did not find a body in the shed, but said the facility's tiny morgue was "overwhelmed".

New Jersey has over 71,000 cases and 3,100 deaths due to the coronavirus.

Over the weekend, the nursing home had requested 25 body bags from authorities. On Monday, police received the anonymous tip about a body being kept in a shed.

Instead, they found 17 bodies kept in a morgue built to house four.

"They were just overwhelmed by the amount of people who were expiring," Andover police chief Eric Danielson told the New York Times.

It is unclear whether any of the 17 deaths were due to the coronavirus.

Chaim Scheinbaum, a co-owner of the nursing home, addressed the morgue problem in an email to New Jersey Congressman Josh Gottheimer, according to the Associated Press.

"The backup and after hours holiday weekend issues, plus more than average deaths, contributed to the presence of more deceased than normal in the facility holding room," he said.

Mr Scheinbaum also said the facility is adequately staffed.

How big is the problem in care homes?

Seventy-six patients have tested positive for Covid-19 along with 41 staff members between the two buildings, according to the Times .

Thirteen bodies were moved to a refrigerated truck at a neighbouring hospital, while the remaining four were to be sent to a funeral home.

The nursing home owner has since obtained a refrigerated truck for bodies, local media reported.

Prime Minister Justin Trudeau said Saturday that Canada won't bring retaliatory or punitive measures against the United States after the Trump administration announced it would prevent the export of N95 protective masks.

Trudeau said he will speak to President Trump in the coming days. He said his officials are having constructive conversations with American officials. Trump announced late Friday he would prevent the export of N95 protective masks to ensure they are available in the U.S.

The prime minister said he'll tell Trump both countries are interlinked in ways that would hurt both nations if supply chains were cut.

"We are not looking at retaliatory measures or measures that are punitive, " Trudeau said.

 "We know it is in both our countries interests to cooperate."

The prime minister noted Canada ships gloves and testing kits to the U.S and said materials from the N95 masks originate in Canada. Canadian nurses also cross the bridge in Windsor to work in the Detroit medical system everyday.

He noted health care workers rely on the masks in Canada.

Manufacturing giant 3M says there are significant humanitarian implications of ceasing N95 masks to health care workers in Canada and Latin America, where 3M is a critical supplier of respirators.

Ontario Premier Doug Ford said he couldn't stress enough how disappointed he was in Trump for making the decision and Alberta Premier Jason Kenney didn't hold back his outrage at Trump's decision.

"It reminds me of what happened in 1939 and 1940 when Canada was part of the fight against global fascism — the United States sat out the first two or three years and actually initially refused to even provide supplies to Canada and the United Kingdom that was leading the fight at the time," Kenney said.

Canada has more than 12,924 confirmed coronavirus cases, including 214 deaths. Twenty two of those deaths are linked to one nursing home in Ontario. Canada has conducted more than 309,000 tests.

Joe Biden, standing on a Las Vegas stage roughly 1,000 feet from the scene of the deadliest mass shooting in modern U.S. history, took on White House rival Bernie Sanders Saturday night for his past vote to exempt gun manufacturers from liability for shootings.

The former vice president devoted the majority of his speech at a Democratic gala on the Las Vegas Strip to deliver a fiery charge against the National Rifle Association and gun manufacturers, vowing to hold gun makers accountable if elected president.

"When I'm the president, we'll take them on, remove the immunity and allow those parents who are trying now to sue for the pain and mayhem they have caused," Biden said on stage at the Tropicana casino-resort. The resort sits adjacent to the grounds where a gunman in 2017 unleashed a torrent of gunfire on a country music festival—an incident that only Biden referred to Saturday night.

Biden, after decrying "carnage in the streets" and the anguish of families whose loved ones were killed in gun violence, said he "will not rest until they're able to sue the gun manufacturers and get a ban assault weapons."

Biden didn't cite Sanders by name when referring to a 2005 federal law that shields gun makers from liability in most crimes, but said, "some of the people running for office voted for that exemption."

"Ladies and gentlemen that immunity was granted. Granted. And it was a horrible, horrible decision," he said.

Biden's speech came after a frenzied Saturday of campaigning across Las Vegas on the first day of early voting in Nevada's Democratic caucuses. Biden, counting on Nevada's diverse population to keep his campaign alive, faces his biggest challenge in the Western state from Sanders, who is seen as the most well-positioned in the state and has reached deep into Latino neighborhoods.

After holding forth on gun violence, Biden lasered in on health care, a sticking point for Sanders with Nevada's most politically powerful labor group, the casino workers' Culinary Union. Again without naming Sanders, Biden repeated a recent argument from the power Culinary Union that a single-payer "Medicare for All" system would eliminate union members' health coverage won through collective bargaining. Biden touted his idea to add a "public option" to existing health insurance markets.

And, he added, "I can actually get my plan passed."

Biden's speech came hours after he  sought to downplay expectations for next Saturday's Nevada caucuses, telling reporters that he did not need to win.

"I just have to do well," he said.

Sanders, who was the first candidate to take the stage Saturday night, laced into billionaire candidate Mike Bloomberg, rattling off a list of heresies against the Democratic party he accused the former New York mayor of committing. Bloomberg implemented "racist policies like stop and frisk" in New York, opposed the minimum wage and higher taxes on the wealthy during the Obama administration, Sanders said.

"The simple truth is that Mayor Bloomberg, with all his money, will not create the kind of excitement and energy we need to have the voter turnout we must have to defeat Donald Trump," Sanders said.

It was a rare attack by name from Sanders. Bloomberg is skipping the Nevada caucuses and was not at the Clark County Democratic Party dinner where Sanders, Biden  and other 2020 contenders spoke.

While the state's formal presidential caucuses are still a week away, Democrats opened the first of four days of early voting across more than 80 locations. State party officials at some sites across Nevada were overwhelmed by long lines.

A spokeswoman for the Nevada Democrats, Molly Forgey, downplayed concerns related to the large early turnout as the political world anxiously watched from afar less than two weeks after Iowa's presidential caucuses turned disastrous . Forgey said Nevada Democratic Party staff and volunteers were working to make every site as efficient as possible.

Early votes cast on paper ballots will be added to in-person caucus votes made on Feb. 22, when Democrats will attend about 2,000 precinct meetings around the state. The Nevada State Democratic Party abandoned its plans to use an app like the one that caused trouble in Iowa and has scrambled to come up with a new system to tabulate results.

Former Sen. Harry Reid, an icon in Nevada's Democratic politics, told reporters that "people should not be counting Joe Biden out of the race yet," but also offered warm words for Sanders' candidacy. When asked he downplayed concerns from some Democrats that Sanders might hurt other candidates should he become the nominee.

Elizabeth Warren, reeling after a weak performance last week in New Hampshire, t ook the stage Saturday night with a raggedy voice, having lost it after a day barnstorming the city.  Warren said she's spent a career fighting powerful interests on behalf of typical Americans.

 "I'm not in this campaign to put forward a bunch of proposals that have been carefully designed not to offend big donors," the Massachusetts senator said. "I'm in this campaign to fight, from a lifetime of fighting for working people. I'm in this campaign to fight from the heart."

Earlier Saturday, Minnesota Sen. Amy Klobuchar tried to introduce herself to the state's voters, addressing an African American festival in a Las Vegas park. She praised the state's voting protections and Democratic legislative majority while pitching her appeal to pivotal Midwestern voters.

"In the middle of the country where I'm from I want a little more Nevada there," Klobuchar said. "My plan is to build a great blue wall around those states and make Donald Trump pay for it."

Canada's transport minister said Wednesday his country is demanding official status in Iran's investigation of the crash of a Ukraine International Airlines jet in Tehran last week.

Iran admits its air-defense forces shot the plane down, having not identified it as a commercial airliner.

All 176 people aboard were killed, including 138 people who were headed for Canada and 57 Canadians.

Transport Minister Marc Garneau said two Canadian investigators are in Iran as part of an international team and have been getting good co-operation, but he wants their participation in the probe formalized.

He said the plane's "black boxes" are in Iranian hands, but another two investigators are ready to go wherever and whenever the recorders are examined.

Canada is organizing a meeting in London on Thursday with representatives from several countries that lost citizens in the crash, to co-ordinate dealings with Iran.

Universities across Canada, meanwhile, held a moment of silence Wednesday to honor the victims as many students, faculty and researchers from more than a dozen Canadian universities were among those who died.