U.S. health advisers endorsed a one-dose COVID-19 vaccine from Johnson & Johnson on Friday, putting the nation on the cusp of adding an easier-to-use option to fight the pandemic.

The acting head of the Food and Drug Administration said in a statement that the agency will move quickly to follow the recommendation, which would make J&J’s shot the third vaccine authorized for emergency use in the U.S. Vaccinations are picking up speed, but new supplies are urgently needed to stay ahead of a mutating virus that has killed more than 500,000 Americans.

After daylong discussions, the FDA panelists voted unanimously that the benefits of the vaccine outweighed the risks for adults. Once FDA issues a final decision, shipments of a few million doses could begin as early as Monday.

“There’s an urgency to get this done,” said Dr. Jay Portnoy of Children’s Mercy Hospital in Kansas City, Missouri. “We’re in a race between the virus mutating — and new variants coming out that can cause further disease — and stopping it.”

More than 47 million people in the U.S., or 14% of the population, have received at least one shot of the two-dose vaccines from Pfizer and Moderna, which FDA authorized in December. But the pace of vaccinations has been strained by limited supplies and delays due to winter storms.

Also read: Pfizer COVID-19 vaccine works well in big 'real world' test

While early J&J supplies will be small, the company has said it can deliver 20 million doses by the end of March and a total of 100 million by the end of June.

J&J’s vaccine protects against the worst effects of COVID-19 after one shot, and it can be stored up to three months at refrigerator temperatures, making it easier to handle than the previous vaccines, which must be frozen.

One challenge in rolling out the new vaccine will be explaining how protective the J&J shot is after the astounding success of the first U.S. vaccines.

“It’s important that people do not think that one vaccine is better than another,” said panelist Dr. Cody Meissner of Tufts University.

Also read:Pfizer studying effects of 3rd vaccine dose

The two-dose Pfizer and Moderna shots were found to be about 95% effective against symptomatic COVID-19. The numbers from J&J’s study are not that high, but it's not an apples-to-apples comparison. One dose of the J&J vaccine was 85% protective against the most severe COVID-19. After adding in moderate cases, the total effectiveness dropped to about 66%.

Some experts fear that lower number could feed public perceptions that J&J’s shot is a “second-tier vaccine.” But the difference in protection reflects when and where J&J conducted its studies.

J&J’s vaccine was tested in the U.S., Latin America and South Africa at a time when more contagious mutated versions of the virus were spreading. That wasn’t the case last fall, when Pfizer and Moderna were wrapping up testing, and it’s not clear if their numbers would hold against the most worrisome of those variants.

Importantly, the FDA reported this week that, just like its predecessors, the J&J shot offers strong protection against the worst outcomes, hospitalization and death.

While J&J is seeking FDA authorization for its single-dose version, the company is also studying whether a second dose boosts protection.

Panel member Dr. Paul Offit warned that launching a two-dose version of the vaccine down the road might cause problems.

“You can see where that would be confusing to people thinking, ’Maybe I didn’t get what I needed,’” said Offit, a vaccine expert at Children’s Hospital of Philadelphia. “It’s a messaging challenge.”

J&J representatives said they chose to begin with the single shot because the World Health Organization and other experts agreed it would be a faster, more effective tool in an emergency.

Cases and hospitalizations have fallen dramatically since their January peak that followed the winter holidays. But public health officials warned that those gains may be stalling as more variants take root in the U.S.

“We may be done with the virus, but clearly the virus is not done with us,” Centers for Disease Control and Prevention director Dr. Rochelle Walensky, said during a White House briefing Friday. She noted that new COVID-19 cases have increased over the past few days.

While it’s too early to tell if the trend will last, Walensky said adding a third vaccine “will help protect more people faster.” More vaccines are in the pipeline.

On Sunday, a CDC panel is expected to meet to recommend how to best prioritize use of the J&J vaccine.

Also read:Malaysia expected to get Pfizer COVID vaccine on Feb 26 

Other parts of the world already are facing which-is-best challenges. Italy’s main teachers’ union recently protested when the government decided to reserve Pfizer and Moderna shots for the elderly and designate AstraZeneca’s vaccine for younger, at-risk workers. AstraZeneca’s vaccine was deemed to be about 70% effective in testing. Canada became the latest country Friday to allow use of AstraZeneca’s vaccine.

Saudi Arabia’s crown prince likely approved an operation to kill or capture a U.S.-based journalist inside the Saudi consulate in Istanbul, according to a newly declassified U.S. intelligence report released Friday that could escalate pressure on the Biden administration to hold the kingdom accountable for a murder that drew bipartisan and international outrage.

The central conclusion of the report was widely expected given that intelligence officials were said to have reached it soon after the brutal Oct. 2, 2018, murder of Jamal Khashoggi, a critic of Crown Prince Mohammed bin Salman’s authoritarian consolidation of power.

Also read: Saudi crown prince denies ordering journalist's murder

Still, since the finding had not been officially released until now, the public assignment of responsibility amounted to an extraordinary rebuke of the ambitious 35-year-old crown prince and was likely to set the tone for the new administration’s relationship with a country President Joe Biden has criticized but which the White House also regards in some contexts as a strategic partner.

The report was released one day after a later-than-usual courtesy call from Biden to Saudi King Salman, though a White House summary of the conversation made no mention of the killing and said instead that the men had discussed the countries’ longstanding partnership. The kingdom’s state-run Saudi Press Agency similarly did not mention Khashoggi’s killing in its report about the call, rather focusing on regional issues such as Iran and the ongoing war in Yemen.

Also read: Saudi sentences 5 to death for Jamal Khashoggi's killing

Khashoggi had visited the Saudi consulate in Turkey planning to pick up documents needed for his wedding. Once inside, he died at the hands of more than a dozen Saudi security and intelligence officials and others who had assembled ahead of his arrival..

Surveillance cameras had tracked his route and those of his alleged killers in Istanbul in the hours leading up to his killing.

Also read: Khashoggi killing: CIA did not blame Saudi crown prince, says Trump

A Turkish bug planted at the consulate reportedly captured the sound of a forensic saw, operated by a Saudi colonel who was also a forensics expert, dismembering Khashoggi’s body within an hour of his entering the building. The whereabouts of his remains remain unknown.

The prince said in 2019 he took “full responsibility” for the killing since it happened on his watch, but denied ordering it. Saudi officials have said Khashoggi’s killing was the work of rogue Saudi security and intelligence officials. Saudi Arabian courts last year announced they had sentenced eight Saudi nationals to prison in Khashoggi’s killing. They were not identified.

The US drug regulator said Thursday it will allow the coronavirus vaccine developed by Pfizer Inc. to be transported and stored for up to two weeks at conventional freezer temperatures instead of the ultracold conditions previously required.

"The alternative temperature for transportation and storage will help ease the burden of procuring ultralow cold storage equipment for vaccination sites and should help to get vaccine to more sites," the U.S. Food and Drug Administration said in a press release.

Before Thursday's announcement, the FDA had required the vaccine to be kept in an ultracold freezer at temperatures between minus 80 C and minus 60 C for a maximum of six months.

Also read: Pfizer COVID-19 vaccine works well in big 'real world' test

With the change, vaccines may now be stored at minus 25 to minus 15 C for up to two weeks, the regulator said.

Pfizer is expected to seek similar approval from regulators in other countries. The vaccine developed by the U.S. pharmaceutical giant and its German partner BioNTech SE has been administered in Japan and other countries.

The Japan unit of Pfizer said Friday in Tokyo it has begun discussions with Japanese drug screening authorities on changes in conditions for the use of its COVID-19 vaccine.

Japanese health minister Norihisa Tamura told a press conference his ministry will thoroughly examine an expected request by Pfizer to allow vaccine storage at higher temperatures.

Also read:Pfizer studying effects of 3rd vaccine dose

"If (the requested changes are) appropriate, we will include them in documents attached (to the vaccine) and inform local governments" in charge of administering vaccines, he said.

Last week, the two companies said they have submitted data to the FDA showing their vaccine remains stable for a total of two weeks when stored at minus 25 C to minus 15 C, which they say are temperatures more commonly found in pharmaceutical freezers.

They may be returned once to the recommended ultracold condition, but total cumulative time of storage between minus 25 C to minus 15 C "should be tracked and should not exceed two weeks," the FDA added.

For actual use, the vaccines are thawed and can be stored for up to five days at standard refrigerator temperature, between 2 C and 8 C. The vaccine can then be mixed with saline diluent and should be administered within six hours, during which doses can be stored at refrigerator or room temperature.

Also read:Malaysia expected to get Pfizer COVID vaccine on Feb 26 

The FDA granted an emergency use authorization for the Pfizer vaccine in December.

The United States launched airstrikes in Syria on Thursday, targeting facilities near the Iraqi border used by Iranian-backed militia groups. The Pentagon said the strikes were retaliation for a rocket attack in Iraq earlier this month that killed one civilian contractor and wounded a U.S. service member and other coalition troops.

The airstrike was the first military action undertaken by the Biden administration, which in its first weeks has emphasized its intent to put more focus on the challenges posed by China, even as Mideast threats persist. Biden’s decision to attack in Syria did not appear to signal an intention to widen U.S. military involvement in the region but rather to demonstrate a will to defend U.S. troops in Iraq.

Also read: US pulling out of northern Syria; full withdrawal possible

“I’m confident in the target that we went after, we know what we hit,” Defense Secretary Lloyd Austin told reporters flying with him from California to Washington. Speaking shortly after the airstrikes, he added, “We’re confident that that target was being used by the same Shia militants that conducted the strikes,” referring to a Feb. 15 rocket attack in northern Iraq that killed one civilian contractor and wounded a U.S. service member and other coalition personnel.

Austin said he recommended the action to Biden.

“We said a number of times that we will respond on our timeline,” Austin said. “We wanted to be sure of the connectivity and we wanted to be sure that we had the right targets.”

Earlier, Pentagon spokesman John Kirby said the U.S. action was a “proportionate military response” taken together with diplomatic measures, including consultation with coalition partners.

“The operation sends an unambiguous message: President Biden will act to protect American and coalition personnel,” Kirby said. “At the same time, we have acted in a deliberate manner that aims to deescalate the overall situation in eastern Syria and Iraq.”

Kirby said the U.S. airstrikes “destroyed multiple facilities at a border control point used by a number of Iranian- backed militant groups,” including Kataib Hezbollah and Kataib Sayyid al-Shuhada. The U.S. has blamed Kataib Hezbollah for numerous attacks targeting U.S. personnel and interests in Iraq in the past.

Further details were not immediately available.

Also read:US begins moving military equipment out of Syria

Mary Ellen O’Connell, a professor at Notre Dame Law School, criticized the U.S. attack as a violation of international law.

“The United Nations Charter makes absolutely clear that the use of military force on the territory of a foreign sovereign state is lawful only in response to an armed attack on the defending state for which the target state is responsible,” she said. “None of those elements is met in the Syria strike.”

Biden administration officials condemned the Feb. 15 rocket attack near the city of Irbil in Iraq’s semi-autonomous Kurdish-run region, but as recently as this week officials indicated they had not determined for certain who carried it out. Officials have noted that in the past, Iranian-backed Shiite militia groups have been responsible for numerous rocket attacks that targeted U.S. personnel or facilities in Iraq.

Kirby had said Tuesday that Iraq is in charge of investigating the Feb. 15 attack.

“Right now, we’re not able to give you a certain attribution as to who was behind these attacks, what groups, and I’m not going to get into the tactical details of every bit of weaponry used here,” Kirby said. “Let’s let the investigations complete and conclude, and then when we have more to say, we will.”

A little-known Shiite militant group calling itself Saraya Awliya al-Dam, Arabic for Guardians of Blood Brigade, claimed responsibility for the Feb. 15 attack. A week later, a rocket attack in Baghdad’s Green Zone appeared to target the U.S. Embassy compound, but no one was hurt.

Iran this week said it has no links to the Guardians of Blood Brigade.

Also read:US warns Russia over missile defense for Syria

The frequency of attacks by Shiite militia groups against U.S. targets in Iraq diminished late last year ahead of President Joe Biden’s inauguration, though now Iran is pressing America to return to Tehran’s 2015 nuclear deal. The U.S. under the previous Trump administration blamed Iran-backed groups for carrying out the attacks. Tensions soared after a Washington-directed drone strike that killed top Iranian Gen. Qassem Soleimani and powerful Iraqi militia leader Abu Mahdi al-Muhandis last year.

Trump had said the death of a U.S. contractor would be a red line and provoke U.S. escalation in Iraq. The December 2019 killing of a U.S. civilian contractor in a rocket attack in Kirkuk sparked a tit-for-tat fight on Iraqi soil that brought the country to the brink of a proxy war.

U.S. forces have been significantly reduced in Iraq to 2,500 personnel and no longer partake in combat missions with Iraqi forces in ongoing operations against the Islamic State group.

A real-world test of Pfizer’s COVID-19 vaccine in more than half a million people confirms that it’s very effective at preventing serious illness or death, even after one dose.

Wednesday’s published results, from a mass vaccination campaign in Israel, give strong reassurance that the benefits seen in smaller, limited testing persisted when the vaccine was used much more widely in a general population with various ages and health conditions.

The vaccine was 92% effective at preventing severe disease after two shots and 62% after one. Its estimated effectiveness for preventing death was 72% two to three weeks after the first shot, a rate that may improve as immunity builds over time.

It seemed as effective in folks over 70 as in younger people.

“This is immensely reassuring ... better than I would have guessed,” said the Mayo Clinic’s Dr. Gregory Poland.

Vanderbilt University’s Dr. Buddy Creech agreed: “Even after one dose we can see very high effectiveness in prevention of death,” he said.

Also read: S. Korea expected to receive Pfizer vaccines in late Feb.-early March: PM

Neither doctor had a role in the Israel study but both are involved in other coronavirus vaccine work.

Both doctors also said the new results may boost consideration of delaying the second shot, as the United Kingdom is trying, or giving one dose instead of two to people who have already had COVID-19, as France is doing, to stretch limited supplies.

“I would rather see 100 million people have one dose than to see 50 million people have two doses,” Creech said. “I see a lot of encouragement on one dose” in the results from Israel, which were published by the New England Journal of Medicine.

Also read; Pfizer COVID-19 vaccine shows 95 pct efficacy, eligible for youths: panel

The vaccine, made by Pfizer and its German partner BioNTech, is given as two shots, three weeks apart, in most countries.

The study was led by researchers from the Clalit Research Institute and Ben-Gurion University of the Negev in Israel, with Harvard University in the U.S. It did not report on safety of the vaccine, just effectiveness, but no unexpected problems arose in previous testing.

Researchers compared nearly 600,000 people 16 and older in Israel’s largest health care organization who were given shots in December or January to an equal number of people of similar age, sex and health who did not receive vaccine. None of the participants had previously tested positive for the virus.

Also read: Study suggests Pfizer vaccine works against virus variant

The vaccine was estimated to be 57% effective at preventing any symptoms of COVID-19 two to three weeks after the first dose, and 94% a week or more after the second dose

Effectiveness was 74% after one shot and 87% after two for preventing hospitalization, and 46% and 92% for preventing confirmed infection. Reducing infections gives hope that the vaccine may curb spread of the virus, but this type of study can’t determine if that’s the case.

There were 41 COVID-19-related deaths, 32 of them in people who did not get vaccine.

Overall, the numbers compare well to the 95% effectiveness after two doses that was seen in the limited testing that led U.S. regulators to authorize the vaccine’s emergency use, Poland said. How much benefit there would be from one dose has been a big question, “and now there’s some data” to help inform the debate, he added.

“Maybe the right thing to do here to protect the most number of people ... is to give everybody one dose as soon as you can. I think that’s a very acceptable strategy to consider,” Poland said.

Israel now has vaccinated nearly half of its population. A newer variant of the virus that was first identified in the United Kingdom became the dominant strain in Israel during the study, so the results also give some insight into how well the vaccine performs against it.

Also read: UN health agency clears Pfizer and BioNTech vaccines

Earlier this week, two U.K. studies suggested benefits even after one dose of the Pfizer vaccine or a different one from AstraZeneca. The U.K. is delaying the second shot for up to 12 weeks after the first one to try to give more people some level of protection