COVID updates: Hawaii is only state to not announce plans to lift mask mandates

Getting the Pfizer or Moderna vaccine series during pregnancy may help prevent COVID-19 hospitalizations for babies under 6 months old, according to a CDC report. 

Prior studies have shown that mothers could possibly pass on antibodies during pregnancy, but this is the first study showing an association between getting vaccinated and protecting the baby. 

The study looked at babies under 6 months who were admitted to the hospital for COVID-19 and compared them to babies under 6 months who were admitted to the hospital for another reason.  

The study found babies with mothers who were vaccinated were 61% less likely to be hospitalized with COVID-19. Of the babies hospitalized with COVID, 84% of their mothers weren’t vaccinated, the study found.

However, this study was conducted when delta was the predominant variant, so more babies need to be studied to see if data changed with omicron. This study also did not look at how effective boosters are in pregnancy. 

-ABC News' Dr. Alexis E. Carrington and Dr. Meaghan C. Costello

The number of COVID-19-positive patients in U.S. hospitals is declining with the same momentum that it surged in early winter. There are now 78,000 Americans with COVID-19 in hospitals; that number was twice as high -- 160,000 patients -- during the nation's peak on Jan. 20, according to federal data.

The U.S. daily case rate has dropped to 161,000 -- down by 80% since last month's peak, according to federal data.

However, experts continue to caution that the U.S. is not out of the woods. Case levels remain much higher than the nation's previous surges, with the U.S. reporting millions of new cases every week and 98% of U.S. counties reporting high transmission. Also, experts point out that many Americans taking at-home tests are not submitting their results, so case totals may be higher than reported.

-ABC News' Arielle Mitropoulos

The omicron variant and its sublineages are estimated to account for 100% of new infections, according to the CDC.

So far, data suggests there are no major differences between the omicron subvariants, but scientists are monitoring them closely.

The original omicron variant is estimated to account for 22.9% of new COVID-19 cases in the U.S. 

A closely related sublineage, BA.1.1, has been the dominant strain since early January and is now estimated to account for 73.2% of new COVID-19 cases.

A second sublineage, BA.2, accounts for an estimated 3.9% of new COVID-19 cases in the U.S., according to the CDC.

-ABC News' Arielle Mitropoulos

Surgeon General Vivek Murthy said his 4-year-old daughter tested positive for COVID-19 this weekend.

At age 4, she’s too young to qualify for the vaccine.

He said she's had a fever and sore throat but is breathing fine.

Murthy tweeted, "Trying to isolate a small child from her 5 y/o brother and parents in a small home is pretty tough. Which is why I’m grateful that my son, my wife, and I are all vaccinated. Even if we contract the virus, it’s unlikely to cause severe illness."

"Few things are worse than worrying about your child’s health. The more we all get vaccinated and take precautions, the more we can protect all our kids," he continued. "I wish a vaccine was available for my child and for all kids. It would protect kids and help parents. Unfortunately more data is still needed from clinical trials for the FDA to make a full assessment."

"Staring at my daughter’s positive test, I asked myself the same questions many parents have asked: Will my child be ok? Could I have done more to protect her? Was this my fault? In these moments, it doesn’t matter if you’re a doctor or Surgeon General," he wrote. "Parenting during the pandemic has been one of the hardest jobs I could have imagined. I have immense respect for the millions of parents who are grappling with the daily, exhausting decision-making that goes into protecting our kids’ health and their education."