Last month there was some excitement in the UK about the potential for a fast antibody test designed to work like a home pregnancy test. Sharon Peacock from Public Health England told reporters that the tests were still in the validation stage but she seemed excited that in a week or so people might be able to order one on Amazon and find out at home if they had antibodies for the virus in a matter of 10 or 15 minutes.

Shortly after word of the tests made news, the UK’s chief medical officer tried to walk it back a bit, emphasizing that no tests would be released until they could be verified as reliable. Roughly two weeks later the UK has just announced that the tests it received from China were not reliable:

None of the antibody tests ordered by the government is good enough to use, the new testing chief has admitted…

Professor Newton said that all of the tests failed evaluations and “are not good enough to be worth rolling out in very large scale”.

Some of the tests have not been total failures, but Professor Newton said: “The test developed in China was validated against patients who were severely ill with a very large viral load, generating a large amount of antibodies . . . whereas we want to use the test in the context of a wider range of levels of infection including people who are quite mildly infected. So for our purposes, we need a test that performs better than some of these other tests.”…

Previously officials had spoken of sending millions of home test kits in days, but Professor Newton said “the idea that we might have it in days was based on the fact that we might just buy the existing test, and at the moment the judgment is that that wouldn’t be the best thing to do. It would be better to try and improve the test”.

That’s apparently what the UK health experts are trying to do. They are offering to work with the companies that manufacturer the tests to create something that will work with more accuracy. But that’s definitely not something that they will be able to roll out in a week.

One of the main reasons to do antibody testing is to identify people who perhaps had a mild case so they can return to work. If the test only works for people who are heavily infected then it’s not very useful for sorting out the less obvious cases. Here’s a Sky News report on the tests from last week.