Answer this then how comes anyone showing symptoms have to self isolate for 2 weeks but boris only 1 week
How long to self-isolate
If you have symptoms
If you have symptoms of coronavirus, you'll need to self-isolate for 7 days.
After 7 days:
if you do not have a high temperature, you do not need to self-isolate
if you still have a high temperature, keep self-isolating until your temperature returns to normal
You do not need to self-isolate if you just have a cough after 7 days. A cough can last for several weeks after the infection has gone.
If you live with someone who has symptoms
If you live with someone who has symptoms, you'll need to self-isolate for 14 days from the day their symptoms started. This is because it can take 14 days for symptoms to appear.
If more than 1 person at home has symptoms, self-isolate for 14 days from the day the first person started having symptoms.
If you get symptoms, self-isolate for 7 days from when your symptoms start, even if it means you're self-isolating for longer than 14 days.
If you do not get symptoms, you can stop self-isolating after 14 days.
https://www.nhs.uk/conditions/coronavirus-covid-19/self-isolation-advice/