Coronavirus cases are rising, nationally and in most states — an ominous trend heading into the week of Thanksgiving.

The big picture: Two-thirds of Americans plan to have Thanksgiving gatherings that resemble their pre-pandemic festivities, according to recent Monmouth University polling. But as cases rise, travel and indoor celebrations will put the millions of unvaccinated Americans at risk.

The intrigue: Holiday gatherings and wintertime have been on the Biden administration's mind for months, and factored into the White House's initial plan to make boosters widely available in September, one senior Biden administration official said.

• "We knew we wanted to be ahead of this. Why do you think we were pushing?" the official said.
• But the FDA and the CDC initially authorized boosters only for smaller, high-risk groups, arguing there wasn't enough data to support broader eligibility. They're expected to begin opening the shots up to all adults as early as today, but only so many people can get their shots in less than a week.

Where it stands: Only 59% of Americans are fully vaccinated, according to the CDC.

• Just 37% of adults 65 and older have gotten a booster dose, leaving millions of older Americans vulnerable to more severe breakthrough infections.
• 10% of children ages 5 to 11 have received a dose — an impressive number, given that the vaccines were only authorized for this age group this month, yet still a small percentage.
• Rapid tests can be a useful tool ahead of travel and gatherings, but they're often in short supply and hard to find.

By the numbers: Cases rose by 20% over the last two weeks, and increases were particularly sharp in some parts of the Upper Midwest and New England.

• Daily deaths, on the other hand, dropped by 13%. But the virus is still killing more than 1,000 Americans per day, on average.

What they're saying: "As we head into the holiday and winter season, now is the time to think about protection for ourselves and our families," CDC director Rochelle Walensky said yesterday.

• "For those who are at higher risk of severe illness from COVID-19 and who are eligible for a COVID-19 booster dose, go out now and get your extra booster dose to protect you," she added. "And for those who are not yet vaccinated...getting vaccinated this week will set you up to being fully protected in time for the holidays and by the end of the year."

What we're watching: The level of risk posed by the holidays depends on whether you're vaccinated, and also varies by region. Although infections among vaccinated people are becoming relatively common, very few result in hospitalization and death.

The bottom line: "This virus is doing what this virus does," said Michael Osterholm, director of the Center for Infectious Disease Research and Policy. "We don’t understand why surges start, we don't understand why they end."