NEW YORK, Nov 23 (Reuters) - Top US infectious disease official Dr Anthony Fauci said on Tuesday (Nov 23) the vast majority of Americans who have been vaccinated against COVID-19 should receive a booster shot, and that an additional dose could eventually become the country's standard for determining who is fully vaccinated.
Fauci and other disease experts have said they expect that COVID-19 will transition this spring from a pandemic phase in the United States to an endemic disease, meaning that the virus will continue to circulate at a lower level, causing smaller, less disruptive but still significant outbreaks in the coming years.
But some are expressing new concern over a rise in US infections in recent weeks, a trend that is likely to accelerate as more Americans travel and gather for US Thanksgiving this week and other upcoming holidays.
"We'd like to get as many people who were originally vaccinated with the first regimen boosted," Fauci said in an interview for the upcoming Reuters Next conference.
Asked to quantify, he said, the "overwhelming majority" of Americans who have been fully vaccinated should now receive a COVID-19 booster shot based on data showing they provide "substantial" protection beyond what is seen from the original inoculation.
To date, about 33 million Americans have received a booster dose. The government recently expanded eligibility for an additional shot to all US adults.
Studies from Israel and other countries have shown that vaccine protection wanes over time. While data first suggested that was mostly a problem in the elderly, there is newer evidence that it occurs among all age groups, Fauci said.
"That's the reason why we're very keen on getting as many people who are originally vaccinated to get a booster ... because they really do work," he said.
As experience with COVID-19 vaccines grows, it is conceivable that the definition of a "full and complete regimen" in the United States would comprise three doses of the mRNA vaccines from Pfizer-BioNTech and Moderna and two doses of the Johnson & Johnson vaccine, he said, similar to what some other countries have done.
"Right now, officially, fully vaccinated equals two shots of the mRNA and one shot of the J&J, but without a doubt that could change," he said. "That's on the table for discussion."
As for the rollout of COVID-19 vaccines for children ages 5 to 11, which started with the Pfizer-BioNTech vaccine earlier this month, Fauci said there is no sign of any new safety issues. "There is no signal at all," Fauci said.
At least 10 per cent of the 28 million eligible children have gotten a first dose, Jeff Zients, the White House coronavirus coordinator, said on Monday.
Fauci said people need to realise that no vaccine is completely without side effects. But when you consider the risks of COVID-19 compared to the very rare risk of an adverse event in a child, "overwhelmingly ... the benefit far, far outweighs the risk."
Asked whether he might consider retiring any time soon, the 80-year-old immunologist who heads the US National Institute of Allergy and Infectious Diseases, said, "I'm not even remotely contemplating that right now."
Fauci said he still wants to see the end of COVID-19 as a pandemic, and he also wants to see progress on ending the HIV/AIDS pandemic, to which he has devoted much of his career.
"There's a lot of unfinished business right now, so I'm not even thinking about walking away."