Is this applicable only in the UK and not the US?

False Ricc..You are WRONG!!

If you think you were exposed to covid the obvious next step.is to get tested. The US government is providing at home test kits at no charge, a limit of 4 kits per household with a US address and zip code.
Do not wait my friend especially for our community, it is vital to address it immediately being immunocompromised.

But at some point, please get the vaccine. I have all the recommended shot. I got Covid last August for the first time. I wasn't sick but I had a terrible cough for a month until my doctor prescribed a cough decongestive.