A rapid COVID-19 blood test manufactured in Canada is being sold in the United States and the U.K., but it's not ready for use here, according to Health Canada.

The rapid blood test — which has the ability to tell within 15 minutes if someone has been exposed to COVID-19 — is manufactured by BTNX Inc. in Markham, Ont.

The federal government is already working with dozens of Canadian companies to manufacture medical equipment and tests related to COVID-19, but it seems that BTNX is not one of them so far.

On April 2, BTNX told CBC News that it will ship 200,000 rapid blood tests to the U.S. in the coming days.

Health Canada is delaying approval of a rapid test for COVID-19 that's made in Ontario. The antibody blood test costs just $10, and is already being used in the U.S. and parts of Europe. @jnorthcottCBC @cbchh #CBCNN pic.twitter.com/RWJD8sRqjH

— CBC Morning Live (@CBCMorningLive) April 9, 2020

However, Chief Financial Officer Mitchell Pittaway said that he would prefer to distribute the $10 tests in Canada.

"As a Canadian company with Canadian staff, ideally we would love to have all of this capacity blocked off for Canada," he said, "but we're not able to step back and not address needs coming from other countries."

Health Canada favours the use of PCR (polymerase chain reaction) tests, which involve inserting a nasal swab into a patient's nose.

Unlike rapid blood tests, nasal swabs can detect the virus in its early stages — although blood tests can be used within five to seven days of infection, and they offer a faster diagnosis.

However, rapid blood tests are also more sensitive than nasal swabs, meaning that they're more likely to declare false negatives and false positives.

Rapid blood tests for COVID-19 are not only in use but have been developed in other parts of the world too.

To combat the COVID-19 pandemic, Hon'ble CM @ysjagan launched the first made in Andhra Pradesh 'COVID-19 Rapid Test Kits', at the camp office in Tadepalli today. Manufactured by @AP_MedTechZone, these kits provide results within 55 minutes of testing.#APFightsCorona pic.twitter.com/UZE4O2jc0j

— CMO Andhra Pradesh (@AndhraPradeshCM) April 8, 2020

But Health Canada told CBC News that it is following the advice of the World Health Organization, "which does not currently recommend serological [blood] tests for clinical diagnosis."

"The department is working with the National Microbiology Laboratory to validate testing and research, along with expert advice, so that we can have confidence in the test results."