-
Now Playing: Millennial doctor uses TikTok to warn kids about the dangers of vaping
-
Now Playing: 2 vaping-related deaths reported in Minnesota
-
Now Playing: New research looks at possible link between obesity and severe COVID cases
-
Now Playing: 8-year-old diagnosed with rare disease gets service dog
-
Now Playing: Man receives rare double lung transplant after battle with COVID-19
-
Now Playing: Website created to help find vaccine appointments promotes another cause
-
Now Playing: US averages 2 million vaccine doses per day
-
Now Playing: COVID-19 relief bill moves to Senate
-
Now Playing: Positive developments of a COVID-19 nasal spray vaccine
-
Now Playing: What we know about COVID-19 vaccine effectiveness against variants
-
Now Playing: A look at critical milestones in the COVID-19 pandemic
-
Now Playing: The push to reopen schools and states dropping mask mandates
-
Now Playing: White House warns states rushing to lift COVID-19 protocols
-
Now Playing: ABC News Live Prime: Wednesday, March 3, 2021
-
Now Playing: The Rundown: Top headlines today: March 3, 2021
-
Now Playing: By the Numbers: State budgets during COVID
-
Now Playing: Are animals at risk of COVID-19?
-
Now Playing: Teachers, child care staff can sign up for vaccine nationwide
-
Now Playing: Biden calls it a mistake for states to lift COVID-19 restrictions
-
Now Playing: Pennsylvania county paying employees to get vaccine