(NEXSTAR) – “Is it time to redefine ‘fully vaccinated’ as three shots?” journalist Dan Rather recently asked in an open-ended question to the Twitterverse.

“Absolutely,” responded Dr. Bob Wachter, head of medicine at the University of California, San Francisco. “If you’re 6 months out and un-boosted, you’re somewhere between protected and unprotected.”

“Yes. Completely,” agreed Eric Feigl-Ding, an epidemiologist and former Harvard researcher.

Urging people to get a booster shot against COVID-19 last month, Connecticut Governor Ned Lamont said, “In my view, if you were vaccinated more than six months ago, you’re not fully vaccinated.”

But the Centers for Disease Control hasn’t changed its definition. The agency still defines someone as fully vaccinated if it’s been two weeks since their second dose of Pfizer or Moderna or two weeks since their single-dose Johnson & Johnson shot. At the same time, the CDC is urging all adults to get a booster shot once they’re eligible.

“We are absolutely encouraging those who are eligible for a boost six months after those mRNA doses to get your boost,” said CDC Director Dr. Rochelle Walensky in a White House briefing last week. “But we are not changing the definition of ‘fully vaccinated’ right now.”

The mixed message – that you’re considered “fully vaccinated” without a booster shot, but you should still get a booster shot – is admittedly confusing. To make matters even more complicated, kids aren’t yet eligible to get booster shots, so any change in the CDC’s definition of “fully vaccinated” would need to have separate criteria for those under 18.

Australia is considering changing its definition of being “fully vaccinated” to include a booster shot requirement, the Guardian reports. Here in the U.S. even the strictest vaccine mandates, such as those in Los Angeles or New York, still only require two shots of Pfizer or Moderna or one shot of J&J to do things like dine indoors or attend concerts. That, of course, is liable to change.

Even Dr. Anthony Fauci, President Biden’s chief medical adviser, left the door open to changing the definition of fully vaccinated if it seems necessary.

“We’ll continue to follow the data, because right now when we’re boosting people, what we’re doing is following them,” Fauci said in an interview with ABC. “We’re going to see what the durability of that protection is, and as we always do, you just follow and let the data guide your policy and let the data guide your recommendations.”