that there is a good chance and greater likelihood - sooner and later that a new vaccine than what are in the market right now - two shots right now - a single shot only - in the planning board,
early next year - before spring they mentioned instead of two shots only one shot - like the "flu shot".

It is much easier to go for one shot - than two shots.

Just like what John B said "wait to the near end" before getting a shot.