When is Oxford vaccine effective from?

[Lollipop1234]

Does anyone have a link stating how long after vaccination the Oxford Vaccine starts being effective?

I thought it was similar to Pfizer, 3 weeks, but can’t find a link anywhere. My friend has just had it and is interested to know.

Tia

www.ox.ac.uk/news/2021-02-02-oxford-coronavirus-vaccine-shows-sustained-protection-76-during-3-month-interval seems to say 22 days

Thanks 👍