Tal Zaks, chief medical officer of Moderna, tells "Axios on HBO" that a COVID-19 vaccine could be available for children by the middle of next year.

Be smart: There will be a coronavirus vaccine for adults long before there is one for kids.

• Moderna hasn't yet begun testing with anyone under 18 years-old, while Pfizer just recently began with teenagers.
• Clinical trials for younger populations should move faster than did clinical trials for adults, because the vaccine-makers will begin with much more human data.
• Zaks also warns not to "overinterpret the results" so far on efficacy, in that they only relate to protecting someone against getting sick, not against transmitting the virus to others.

The bottom line: Schools may not be able to fully reopen by late spring, even if all adult staff are vaccinated.