As already said, it is unethical to test new medicines on pregnant women. However, it is inevitable that some women who receive the vaccine will be/become pregnant soon after, even if not actively ttc. I imagine it will be from them that information will eventually be accumulated which in time may lead to it being approved for this group after all.
JVT said as much - no pregnant women were included in the trial but a few did become pregnant after receiving the vaccine, and “we have seen nothing alarming”. However, the numbers are so small they can’t be relied on to say it is safe.
Re under 50’s - I am almost certain they will be vaccinated in due course, otherwise why would we have bought so many doses? It’s just they are trying to vaccinate the most at risk first.
I believe there are now trials of one of the vaccines in over 12’s, I can’t remember which one, sorry.