WASHINGTON – Rep. Ro Khanna, D-Calif., entered the debate over giving the COVID-19 vaccines as a single dose and delaying a second dose, urging President Joe Biden’s administration to consider a new vaccine strategy to get more doses out to Americans.
In a letter sent Wednesday to Centers for Disease Control and Prevention Director Rochelle Walensky and COVID-19 task force coordinator Jeffrey Zients, Khanna urged them to work with the Advisory Committee on Immunization Practices, a CDC committee, “to gather and consider data” on the effectiveness of single-dose vaccinations. Khanna is the first lawmaker to publicly call on the Biden administration to consider the strategy in hopes of sparking a debate on the question amid a bumpy vaccine rollout.
“Every person we vaccinate today is a life potentially saved. If clinical data supports an effective one-dose vaccine regimen, it could nearly double our daily vaccination numbers, simplify administration, and reduce COVID-19 deaths in the long run,” he wrote.
At this point, there is no clinical data to support the idea that one dose of the Pfizer-BioNTech and Moderna vaccines is sufficient to provide protection against COVID-19.
In large clinical trials of both vaccines, participants who received the active vaccine were less likely to catch COVID-19 in the three to four weeks between shots than people who received a placebo – suggesting they had gotten some protection from their first shot.
But since they all received the second shot, it’s not clear how protected they were or for how long.
Both companies decided to pursue two-dose regimens for their vaccines because early data suggested that two doses would provide substantially more protection for more time.
Khanna’s position is in contrast with that of the Biden administration, which has supported delivering both doses of the vaccine at the recommended intervals of 28 days for the Modernavaccine and 21 days for the Pfizer–BioNTech vaccine.
A handful of public healthexperts have advocated giving the Moderna and Pfizer-BioNTech vaccine in single-dose regimens rather than the currently recommended two doses to rapidly build immunity among Americans.
“We still want to get two doses in everyone, but I think right now, in advance of this surge, we need to get as many one-doses in as many people over 65 as we possibly can, to reduce serious illness and death that is going to occur over the weeks ahead,” said Michael Osterholm, an epidemiologist who advised the Biden transition team, on Sunday’s “Meet the Press,” referring to a potential surge in cases as new COVID-19 variants spread.
And Robert Wachter, chair of the department of medicine at the University of California-San Francisco, and Ashish Jha, dean of the Brown University School of Public Health, wrote in a Jan. 3 Washington Post op-ed, “We should give people a single vaccination now and defer their second shot until more doses of vaccine become available” because of vaccine supply constraints.
Other vaccine experts strongly disagree with this approach.
It’s a messaging problem, said Dr. Paul Offit, an infectious disease physician. When experts say it’s OK to delay a second shot, the general public takes that as permission to skip the second dose entirely.
“‘Get it when you can’ never seems to really work in the real world,” said Offit, who directs the Vaccine Education Center at Children’s Hospital of Philadelphia.
With the hepatitis B vaccine, for instance, infants who get the shot at birth are far more likely to finish the series than those who don’t get that first dose, he said.
And if people have only partial immunity from a single dose of the vaccine, they are more likely to become breeding grounds for dangerous variants.
“A lesser immune response is more likely to allow for escaped mutants,” Offit said. “If you’re trying to create escape mutants in the lab, that’s how you do it.”
Biden administration officials said Monday that they were not planning on changing their strategy to administer two doses of the vaccine.
Walensky, the CDC director, told reporters “we should follow the science” in deploying the vaccines and noted there was an “ongoing concern that we would see the emergence of more variants if there was low-level virus and it was allowed to mutate.”
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, reiterated the current policy about getting two doses when “dealing with a two-dose regimen” like Pfizer-BioNTech and Moderna’s, saying “the first priority will always be to get the people who have gotten their first doses to get their second doses. And then additional doses will be given to the next group of people who will get their first doses.”
“There are no doses that are hanging around,” he said. “A dose that is available is going to go into someone’s arm.”
Khanna told USA TODAY in a phone interview he wanted the CDC to consider the change because of a potential “five-alarm fire” the country faced with another surge in COVID-19 cases.
The country will “have to make decisions about saving lives” and needed a “data-driven approach,” he said.
Khanna acknowledged some concerns about a possible false sense of security among people who received a single dose but argued that given the severity of the pandemic, “people are not going to be lulled into complacency” or be confused about a second dose.
Asked about the Biden administration’s stance and concerns about a single dose not protecting against mutations, Khanna said “let’s get the data out there,” adding it was a question that should be discussed openly.
The Centers for Disease Control and Prevention updated its vaccine guidance at the end of January to say the second dose of a two-shot vaccine can be administered up to six weeks after the first.
The mRNA COVID-19 vaccines developed by Pfizer-BioNTech and Moderna require two doses, given three weeks and one month apart, respectively. But second shots can still be administered beyond that time frame, up to 42 days after the first, the CDC said late last week. There’s no data on doses administered after that time.
The agency also said a person may receive a different vaccine for the second shot only in “exceptional situations” where the first-dose vaccine is unknown or unavailable. Clinical trials did not evaluate the safety or effectiveness of interchanging vaccines.
Contributing: Karen Weintraub, Michael James, Ryan Miller and Grace Hauck