There's a reason Canada and other wealthier nations bought five or seven times as many vaccine doses as they need.
Because you don't know in advance which vaccines will be approved and become available first - let alone any later supply problems you may encounter.
The unused vaccines can be donated to less affluent nations.
By why waste an extra $35 billion on excess vaccines from various makers? It's so much easier and efficient to spent Seven Trillion Dollars keeping your economy on life support and wait your turn at the end of the line for enough of one of the eventual winning and available vaccines?