The Congressional Budget Office doesn't expect much from House Democrats' plan to temporarily expand health care coverage through the Affordable Care Act, Axios' Sam Baker writes.

The big picture: According to CBO's estimates, Democrats' proposals would cover fewer than 2 million uninsured Americans — at a cumulative cost of over $50 billion.

Details: Democrats on the House Ways and Means Committee want to make more people eligible for the ACA's premium subsidies and increase the value of those subsidies for people who already get them. Both changes would be temporary.

• Those changes would cover about 1.3 million uninsured people next year, CBO projects, and would end up costing the federal government about $34 billion.
• Offering full subsidies to people receiving unemployment benefits would cost another $4.5 billion. And people wouldn't have to pay back excess subsidies from last year, adding another $6.3 billion.
• Separately, Democrats' plan to subsidize COBRA benefits would cover about 600,000 otherwise uninsured Americans, along with over 1.6 million more who would have otherwise had some other form of coverage, at a cost of $7.8 billion.

By the numbers: That comes out to nearly $53 billion, for a set of policies that would, per CBO's estimates, cover 800,000 uninsured Americans this year, 1.3 million in 2022 and 400,000 in 2023, before phasing out.

Sam's thought bubble: This does not seem like a particularly efficient, or even effective, way to achieve Democrats' primary goal: Offering a bridge to the millions of people who lost their health insurance when they or their family members lost their jobs amid the pandemic.

Miserable winter weather sweeping across the U.S. forced several places to cancel vaccine appointments and delayed some vaccine deliveries, AP reports.

Details: In Houston, the public health agency lost power and had to distribute thousands of shots before they went bad.

• The weather is expected to disrupt vaccine shipments from a FedEx facility in Tennessee and a UPS installation in Kentucky, which both operate as shipping hubs for several states, the Biden administration said.
• The U.S. government is projecting "widespread delays" in vaccine shipments in the next few days, a Centers for Disease Control and Prevention spokesperson told the Washington Post.

The other side: The administration announced yesterday that the number of vaccines being sent weekly to states will increase again, from 11 million doses to 13.5 million, per WashPost.

• And FEMA launched its first mass COVID-19 vaccination sites yesterday in Los Angeles and Oakland. The sites are part of the administration's plan to distribute vaccines faster and to hard-hit communities.

Most teachers and school staff who are back in the classroom feel comfortable with the return to in-person classes, according to recent polling from the American Federation of Teachers.

Why it matters: Teachers who are still fully remote said they weren't comfortable with the idea of a return to the classroom — but the teachers who have returned seem to think it's gone just fine, Axios' Marisa Fernandez writes.

Details: The poll, which surveyed a representative sample of 800 AFT members, including 600 teachers and 200 other paraprofessionals and school-related personnel earlier this month.

• Few schools have returned to full-time in-person instruction. 60% of teachers said their schools are using a hybrid model, but just 40% said schools should use a hybrid model — while 35% said schools should remain entirely virtual.

Go deeper: Read the full polling results.

Most of us have gotten used to shoving nasal swabs up our noses to check for the virus that causes COVID-19. But there's also another kind of test that's still being researched: a saliva test that may tell us more, Axios' David Nather reports.

Driving the news: The Yale School of Medicine is promoting a study by its researchers that suggests the saliva test might not just be less invasive — it might also be a better way to tell who's going to get severely ill.

How it works: By gathering a bit of saliva to see if it contains the virus, doctors can get a pretty good idea of whether a patient has an advanced enough case that they should receive an early treatment like monoclonal antibodies, according to the Yale researchers.

• If the virus has gotten into the saliva, that's a sign that it's probably gotten into the lungs, which is where it can do the most damage.

The catch: Right now, the saliva test can only be performed in authorized labs. It's not the kind of test the average person can just go out and get.

• But the Yale researchers say it might become more widely available if more studies confirm its usefulness and the FDA approves it. (It just has an emergency use authorization at the moment.)

President Biden sought to clarify what his administration means by promising to open schools in the first 100 days of his presidency, insisting last night at a CNN town hall that "the goal will be five days a week."

Most Americans will be able to get their coronavirus vaccines between the middle of May and early June, President Biden's chief medical adviser Anthony Fauci told CNN on Tuesday.

U.S. airlines carried about 60% fewer passengers in 2020 compared with 2019, according to Department of Transportation data released Tuesday.

The CDC is in discussions with more than a dozen labs about expanding genomic sequencing efforts, Politico reports.

New coronavirus variants are rapidly spreading across Europe as it faces a shortage of vaccines, forcing governments to extend or potentially tighten restrictions, the Wall Street Journal reports.