Guest: Ed Keenan, The Star's Washington Bureau Chief

This week New York City became the first city in the United States to require proof of COVID-19 vaccination for indoor spaces and activities. Just two months after Washington Bureau Chief Ed Keenan reported about the city's reopening joy and successful vaccinations, COVID cases are rising in all 50 U.S. states, driven by the Delta variant and surging in places where vaccinations rates are low. What changed the game so quickly in the U.S.? Health experts said it comes down to who got vaccinated and who did not. Today on "This Matters," we take a look at what happened and what this might mean for Canada.