woman in bed with mask

There are worrying signs about the COVID-19 virus, despite nearly 1 million kids getting vaccinated against the coronavirus in the past week and another 26 million adults getting a third dose of the vaccine.

The highly contagious delta variant is driving up hospitalizations in the Mountain West and fueling outbreaks in the North. It appears the virus is gaining ground as colder temperatures set in, moving people indoors where they are closing windows and breathing stagnant air.

“We are going to see a lot of outbreaks in unvaccinated people that will result in serious illness, and it will be tragic,” Donald Milton, M.D., from the University of Maryland School of Public Health, told the Associated Press.

Recent outbreaks have closed schools in Boston and overwhelmed hospitals in New Mexico and Colorado. New Mexico has run out of beds in intensive care units, despite having an above average vaccination rate.

Meanwhile, U.S. health officials are keeping a close eye on a delta-plus variant that has been detected in eight states and the District of Columbia. While the AY.4.2 “sub-lineage” of delta may spread faster than the original variant, health experts say there is no evidence that it causes more severe illness. They also report COVID-19 vaccines appear to remain effective against it.

The Centers for Disease Control and Prevention estimate the AY.4.2 has accounted for less than 0.05% of COVID-19 infections circulating in recent weeks, but federal health authorities are still tracking it closely.

“We have teams that are constantly reviewing the genetic sequence data and looking for blips, an increase in a certain proportion or just something that’s completely new,” Summer Galloway, M.D., executive secretary of the federal government’s SARS-CoV-2 Interagency Group, told CBS News.

The number of daily cases of COVID-19 have declined from a high this year of 201,178 on Sept. 1 to 133,195 on Nov. 8, according to the CDC. About 67% of the U.S. population is now fully vaccinated.