Coronavirus Watch: What happened to Novavax, AstraZeneca vaccine trial participants?

What ever happened to the 50,000 Americans who volunteered for the Novavax and AstraZeneca vaccine trials?

Many hoped it would only be a short wait before the COVID-19 vaccines would be federally authorized. But now, months later, both companies have yet to submit their vaccines for authorization in the U.S., and the trial participants find themselves in limbo.

While other fully vaccinated people are going to gyms, movie theaters and bars, some Novavax and AstraZeneca trial participants are struggling to convince strangers they're protected. Read more from USA TODAY's Karen Weintraub here.

It's Tuesday, and this is Coronavirus Watch from the USA TODAY Network. Here's more news you need to know.

• Vaccines boost immunity in people who have had COVID-19, according to a new study from the CDC based on data from people in Kentucky who contracted COVID-19 a second time.
• Most Florida children are returning to school in areas where COVID-19 outbreaks are far more intense than they were when school started last year. In most counties, cases are at least four times higher than a year ago, a USA TODAY Network analysis of Johns Hopkins University data shows. Five counties report a more than tenfold increase.
• The superintendent of the school district in the capital of Florida said Monday that he will require masks, even as Republican Gov. Ron DeSantis issued an order suggesting punishments for school districts that mandate mask-wearing in classrooms.
• The second-largest school district in Texas, Dallas Independent School District, is defying the governor's executive order barring mask mandates, officials announced Monday. Following their announcement, Austin Independent School District joined them. 
• Americans should avoid travel to France, Israel, Iceland and other destinations regardless of vaccination status, the CDC said Monday.

Today's numbers: The U.S. has reported more than 35.9 million COVID-19 cases and 617,500 deaths, according to data from Johns Hopkins University. Worldwide, there have been more than 203.6 million cases and more than 4.3 million deaths. About 59% of people in the U.S. have received at least one vaccine shot, and about 50% are fully vaccinated, according to the CDC.

Tracking the pandemic: See the numbers in your area here. See where cases are rising here. See vaccination rates here. And here, compare vaccinations rates worldwide and see which countries are using which vaccines.

– Grace Hauck, USA TODAY breaking news reporter, @grace_hauck