Researchers in Cardiff and the US work out how the Covid jab may be linked to the extremely rare clots.
Companies are deciding against holding a big bash in favour of allowing small, optional gatherings.
People should try to reduce Covid transmission so we can all enjoy Christmas "knees up", Therese Coffey says.
The new target is unveiled in response to concerns raised by a committee of MPs.
The 16-year-old was reported missing and found dead in Hamilton, South Lanarkshire, on Sunday.