(ABC4) – As the U.S. COVID-19 death toll nears 500,000, Dr. Anthony Fauci continues to call on Americans to continue taking safety precautions to slow the spread of the virus as vaccinations continue.

President Joe Biden‘s chief medical adviser joined Good Morning America on Monday to discuss the ongoing fight against COVID-19. You can watch his responses in the video player above.

He started by saying he believes the pandemic did not have to be this bad.

“It’s so tough to go back and try to do a metaphorical autopsy on how things went,” Dr. Fauci explains. “It was bad, it is bad. I think these numbers are so stunning.”

He continues, saying that rather than looking back at how things have been, we should “move forward and be completely committed, as a unified country, to just go at this together.”

“This is a common enemy, we’ve all got to pitch in. We’re in some good shape now with the vaccines, but it’s going to be a race against the infections that keep coming and our ability to do two things, and do it well.”

Dr. Fauci explains that those two things are to continue practicing health guidelines – like wearing a mask, avoiding group gatherings, and washing your hands – and distributing vaccines as quickly and efficiently as possible. On Sunday, Dr. Fauci stated that Americans may be wearing masks into 2022.

He also discussed recent studies that suggest one dose of the Pfizer and Moderna vaccines may be enough for protection for those who have had the virus.

Dr. Fauci says that while they need to look at that data carefully, “superfically, looking at it, it looks really quite impressive.”

“If it holds true, we’re always open to considering that in people who do get infected, that they may need only one dose,” he explains. “But you really want to look at the data first before you make any policy decisions.”

When asked about an op-ed in the Washington Post that says we could see herd immunity by April, Dr. Fauci responded that it is not time to declare victory just yet.

He explains that while the curve of new cases and seven-day averages are trending downward, variants of the virus pose a threat.

“We have variants out there that could actually set us back,” he says. “Fortunately, the vaccines we are distributing now work well against the UK variant.”

That U.K. variant, according to Dr. Fauci, is expected to become the dominant variant in the U.S. He adds that the South African variant does not appear to be dominant. That U.K. variant was detected in Utah in January.

“We do have a good vaccine against [the U.K. variant],” he says. “That is more incentive to say, rather than think about declaring victory, and saying ‘well, we have herd immunity, we’re in good shape,’ we’ve got to keep pushing and pushing because this thing could bounce back with the variants very, very quickly. We cannot declare victory because that curve is coming down so sharply.”