White House medical adviser Dr. Anthony Fauci said Wednesday that more and more data indicate that the omicron variant of COVID-19 may not cause as many severe infections as past strains. However, he warned hospital systems in some parts of the country could still get overrun because the strain spreads so quickly.

During Wednesday's briefing by the White House COVID-19 response team, Fauci shared with reporters data recorded by South Africa and the United Kingdom, both of which showed that omicron resulted in a smaller percentage of severe COVID-19 infections.

He also noted that recent data shows that the U.S. case rate is climbing much higher than the current hospitalization rates.

"The spike in cases is out of proportion to the increase in hospitalization. So if one looks at 14-day averages, the data, as of last night, indicate a plus-126% increase in cases and an 11% increase in hospitalizations," Fauci said. "We must remember that hospitalizations and deaths are lagging indicators. However, that pattern in the disparity between cases and hospitalizations strongly suggests that there will be a lower hospitalization-to-case ratio when the situation becomes more clear."

On Monday, the Centers for Disease Control and Prevention said that the U.S. smashed the all-time recorded for daily COVID-19 cases, with nearly 450,000. However, CDC Director Dr. Rochelle Walensky noted Wednesday that hospitalizations and deaths have remained fairly steady in the past seven days.

"All indications point to having a less severity of omicron versus delta," Fauci said.

However, Fauci warned that because omicron is so transmissible, it could still lead to hospitals becoming overwhelmed in the weeks ahead.

"Increased transmissibility of omicron resulting in an extremely high volume of cases may override some of the impact of the lower disease severity," Fauci said. "And so we should not become complacent, since our hospital system could still be stressed in certain areas of the country."

Fauci added that the U.S.'s best protection against omicron is vaccines, as "the risk of severe disease in any circulating variant, including omicron, is much, much higher for the unvaccinated." He and other top health officials recommend everyone in the U.S. get vaccinated and a booster shot when they are eligible to get one.

While the omicron variant appears to be more resistant to COVID-19 vaccines, Dr. Anthony Fauci stressed Wednesday that the vaccines still offer substantial protection against the newly-discovered variant.

Fauci also urged Americans not to wait for omicron-specific shots and seek out vaccinations — whether first-time shots or booster shots — as soon as possible.

"Our booster vaccine regimens work against omicron," Fauci said Wednesday during a White House COVID-19 response team briefing. "At this point, there is no need for a variant-specific booster. And so the message remains clear. If you're unvaccinated, get vaccinated. And particularly in the arena of omicron, if you're fully vaccinated, get your booster shot."

Fauci, a top medical adviser for President Joe Biden, says Pfizer's COVID-19 vaccine and a booster shot is 75% effective against omicron. That's significantly lower than the vaccine's effectiveness against other variants, though it still offers significant protection against severe infection.

Pfizer's CEO recently said his company would be able to develop a vaccine within 100 days that's made specifically to fight the omicron variant.

Dr. Rochelle Walensky, the director of the Centers for Disease Control and Prevention, added Wednesday that COVID-19 infections and deaths are on the rise across the country. She noted that the omicron variant represented about 3% of new cases in the U.S. That number is expected to increase in the weeks ahead.