Australian laws prevent self-test kits for serious infectious diseases being sold to the public. The tests detect antibodies that our immune systems naturally make to fight SARS-CoV-2, the virus that causes COVID-19. However, these tests will not be as accurate as the ones currently used at testing centres, which look for DNA from the virus. They will only be able to pick up antibodies five to seven days after a person becomes infected. They may also be prone to false positives if a person has previously been infected by one of the several coronaviruses humans are prone to. They are likely to be most useful for people who have had symptoms for at least a week, according to the Public Health Laboratory Network.

Loading The Australian government is working to source 1.5 million blood tests from a variety of manufacturers. British Prime Minister Boris Johnson’s key medical and scientific advisers have repeatedly stressed that someone who has been infected cannot be reinfected, despite some isolated reports of that happening in other countries. Professor Sharon Peacock, the director of Public Health England's National Infection Service, told MPs the kits were in the final stages of testing at a laboratory in Oxford and could be approved for mass distribution by the end of this week. Johnson had previously revealed work was underway to develop the "game-changing" test but Peacock's evidence to MPs on Wednesday represents a major development given how soon the kits are likely to be rolled out.

Like much of the world, Britain is in lockdown and vast swaths of the economy have been shut down in a bid to limit the spread of the virus. While the virus is dangerous and can cause serious illness and death, many people contract it without displaying any symptoms and could be stuck at home even though they have developed immunity. The UK had 9529 confirmed cases by Wednesday but the true figure is likely to be in the hundreds of thousands. "Once we are assured that [the kits] do work, they will be rolled out into the community," Peacock said. 'In the near future people will be able to order a test that they can test themselves, or go to Boots, or somewhere similar to have their finger prick test done.' Professor Sharon Peacock, England's National Infection Service "In the near future people will be able to order a test that they can test themselves, or go to Boots, or somewhere similar to have their finger-prick test done."

Asked whether the tests would be available in "days" rather than weeks or months, Peacock replied: "Yes, absolutely". Chief Medical Officer Chris Whitty later said while it was possible key workers could access the test quickly, the broader public would unlikely be able to access it from next week. Peacock said the equipment looked like a pregnancy test and would be low cost, if any charge was applied at all. Downing Street was expected to reveal new details about the new regime later on Wednesday. "You prick your finger like a diabetic would, and get a drop of blood and put it on a filter paper and then run some liquid to make that blood run into the test zone," Peacock said. "Then you will read it to see whether you have two types of antibodies: one is IGM, which arises very early in an infection, and the other is IGG, which is the body reacting to the virus."

Loading Priority will be given early to key workers including doctors and nurses before the wider community can access the tests. "This is not just for key workers. This is for the general population and over time we are expecting a proportion of the population to be positive and that will allow them to get back to work," she said. Whitty last week said the antibody tests were an "absolute priority". "We'll be able to say to somebody, 'You've had this virus, you're not likely to get it again at least in the immediate term, and now we can be confident you can return to work and now we can be confident you don't need to be taking some of the precautions you’ve been taking to date'," he said.