The updated recommendation on Health Canada website NOW is:
2 doses for 6months-3yrs and 3-9yrs.
However, no one is sure for NOW whether the 2nd shot is needed,
as there is not enought data yet from clinical trials. I know some trials
are just finished, but not analysed/reported, some others are ongoing.
As the MINIMUM interval between 2 shots is 21 days,
I'll wait a bit longer for the second shot for my 3.5 yrs child.
At that time, hopefully Health Canada will know better about the best dosage.