The Biden administration is expected to soon recommendbooster doses of the COVID-19 vaccine for everyone, but that decision fails fundamental ethics tests, according to interviews with physicians and medical ethicists.

Why it matters: There is still a global shortage of vaccines. Even amid concerns of the spreading Delta variant, experts say it's difficult to justify a third dose for relatively healthy people in the U.S. when many others haven't gotten their first.

Driving the news: The booster shots would likely be administered around eight months after someone received their two mRNA vaccine doses from Pfizer or Moderna their single Johnson & Johnson shot, according to initial reports.

• An independent CDC panel and the FDA have not signed off on this plan yet.
• This possible plan comes a week after the CDC and FDA formally recommended the nation's 9 million immunocompromised people get a third dose of the Pfizer or Moderna vaccine.
• Data have indicated for months that the immunocompromised, especially organ transplant patients, were less protected from the two-shot course.
• A third dose for the immunocompromised is reasonable, ethicists say, because three doses should have been their default regimen, and it will give a boost in protection to a group that is more likely to end up in the hospital from COVID-19.

Yes, but: "Once you get to anybody who wants to get a third dose, then I think other people in other countries start to have a rightful basis for complaint," said Govind Persad, a health policy and ethics professor at the University of Denver.

• The vaccines appear to be less effective as time goes on, but there's no rigorous data quantifying that yet.
• The vaccines still prevent almost all instances of death and hospitalization from severe disease.
• The risk of vaccinated people with normal immune systems passing the Delta variant on to other vaccinated people also appears very low.
• Meanwhile, the coronavirus is raging in low-vaccinated places like Botswana, Cuba and Iran, which "translates into disparities in mortality rates from COVID-19," ethicists wrote in JAMA last week.

"We have people in sizable numbers who have zero protection," said Ruth Faden, a bioethicist at Johns Hopkins University and member of the World Health Organization's panel that advised against boosters except for high-risk people. "The global ethics case is clear."

Reality check: The U.S. has bought enough vaccine doses to immunize everyone, and that stockpile has come at the expense of other countries.

• Experts agree no vaccine should be wasted or allowed to expire, and it also may not be logistically feasible for the U.S. to ship some of its surplus doses elsewhere.
• But variants have become a top concern precisely because of the maldistribution of vaccines.
• "This virus has proven what most pathogens do: They mutate," said Doug Diekema, a bioethicist and physician at Seattle Children’s Hospital. "The best way to stop that is to stop transmission, and to do that, you have to get as many people vaccinated as possible."

The bottom line: "The Delta variant didn't come from nowhere," Faden said. "To have a better chance of containing this pandemic, we have a self-interested reason in seeing vaccination coverage go up in people outside of our country."