WASHINGTON: US government advisers will debate Friday if there's enough proof that a booster dose of Pfizer's COVID-19 vaccine is safe and effective.
It's the first public step toward deciding which Americans may get an extra dose and when.
The Food and Drug Administration on Wednesday posted much of the evidence that it will ask outside experts to consider at Friday's meeting.
But the agency struck a neutral tone in reviewing the data and discussing the rationale for boosters.
That careful approach is notable given that White House officials have been previewing a booster campaign that they hoped to begin next week.
Pfizer is making the argument that while protection against severe disease is holding strong in the U.S., immunity against milder infection wanes somewhere around six to eight months after the second dose.
The drugmaker is pointing to data from Israel, which began offering boosters over the summer.
The US already offers an extra dose of the Pfizer or Moderna vaccines to people with severely weakened immune systems.
The Biden administration is considering requiring vaccinations against COVID-19 and contact tracing of international visitors after the US revamps current broad restrictions that bar many foreigners from travelling to the US, a top White House adviser has said.
Jeffrey Zients, the White House coronavirus response coordinator, said on Wednesday that because of the recent increase in COVID-19 cases, current travel restrictions will remain in place until the administration rolls out a "new system" for regulating international travel.
The system will include a prominent role for the Centers for Disease Control and Prevention.
"We will also be putting in place contact tracing to enable CDC to follow up with inbound international travelers and those around them if someone has potentially been exposed to COVID-19," Zients said, "and we are exploring vaccination requirements for foreign nationals traveling to the United States."
Zients made the comments to a panel that advises Commerce Secretary Gina Raimondo on issues around travel and the U.S. tourism industry.
The U.S. currently bars most non-Americans who have traveled to China, India, the United Kingdom, most of Europe, Brazil and other countries in the previous 14 days.
Airlines and other travel companies have pushed the administration to ease the restrictions, particularly on U.K. visitors.
Separately, Anthony Fauci, the government's top expert on infectious disease, has said he would support a proposal to require vaccination for people on domestic flights.
The airline industry is adamantly opposed to such a requirement, saying it would be difficult to enforce and could lead to long lines at airports.
Industry officials say it would be unfair to single out air travelers with a mandate that would not affect people who travel by train, bus or car.
The country will spend $470 million to learn more about long COVID-19, its causes and potential treatments.
The National Institutes of Health announced the plans Wednesday with a grant awarded to New York University and a goal of enrolling up to 40,000 adults and children nationwide.
The effort, dubbed RECOVER, will involve researchers at more than 30 U.S. institutions.
"This is being taken with the greatest seriousness at a scale that has not really been attempted with something like this,'' Dr. Francis Collins, NIH director, said at a briefing Wednesday.
Collins says its estimated 10% to 30% of people infected with COVID-19 may develop persistent, new or recurring symptoms that can last months or perhaps years.
Long COVID is an umbrella term for symptoms that linger, recur and show up for the first time four weeks or more after an initial infection.
It also includes heart inflammation and multisystem inflammatory syndrome, a rare but serious condition that can occur in children after a COVID-19 infection.
Pain, headaches, fatigue, brain fog, shortness of breath, anxiety, depression, chronic coughs and sleep problems are among the reported symptoms of long COVID.
Possible causes include the virus lingers in tissues and organs or it overstimulates the immune system.