There are now very good and reliable antibody tests available which require a whole 10 mins to do, the proverbial dog can do it with near no training. They cost 10 quid a pop, are made in the UK and are very reliable (high sensitivity and specificity) you can get 7 million a week.
So why they are not implemented at airports and other ports of entry is anybody's guess.
Out of interest, at what point in infection do you have antibodies. I thought part of the issue with covid19 was the asymptomatic period before you developed symptoms?
I thought there was also suggestion that the antigen test doesn't detect early carriers?
I am not a virologist, but all the briefings we've had in public transport have effectively said there's not a quick reliable way to detect who is carrying it.
3 to 7 days after getting infected you get detectable levels of IgM antibodies.
So it is not ideal but a lot better what is done now - i.e. nothing; or what is proposed post 1/6 - sticking everybody in a room for 2 weeks indiscriminately;
The tests that I am talking about also looks for IgG - that comes up detectable after 21 days so indicates a past infection.
I nicked that chart from here -https://www.biotrend.com/lesen/newslett ... -2264.html
It also shows why Asian countries do pax checks on airports with thermometers and rapid tests.
No doubt their science is different than that of the UK
Maybe one day that the horizon doesn't stop at the coast line or just extends to the US.