Ask the Pharmacist

Q) I heard that rapid antigen tests are apparently one of the keys to reopening our lives and that they are now available to us for free. How do we access them?

A) What a timely question; After months of not being able to access COVID rapid tests after their high demand due to the Omicron variant over the holidays depleted supplies, we, and many other distributors, have rapid tests available. And the best news is that they are free and require very little in the way of hassles to acquire. All you need is a form of identification to show you are an Ontario citizen such as an Ontario drivers licence or health card.

Starting the week of February 9th, Ontario began distributing 5.5 million of these tests each week over eight weeks. Over 2,300 grocery stores and pharmacies will provide a box of 5 tests per household while supplies last. The government is hoping to resupply those locations whose supplies dwindle.

As a reminder, rapid antigen tests are simple to use and provide a quick and a reasonably accurate answer as to whether you might have COVID in as little as 20 minutes. Although some people have access to rapid tests from other manufactures, the protocol is similar for all, however there might be slight variations, so be sure to read the directions thoroughly before testing to ensure the correct protocol is followed.

The test involves using the supplied swab and inserting it about 2.5cm in the nostril and rotating it around both nostrils 5-10 times. The applicator is then dipped into the supplied testing solution and swirled to mix. Then squeeze the test tube walls against the swab 10-15 times before letting it sit for 2 minutes. Remove the swab, attach the cap and put 3 drops (this may vary depending on the manufacturer) into the test well of the test cassette. This cassette looks very similar to home pregnancy tests which have been around for decades. The results will be ready in 15 minutes. DO NOT READ THE RESULTS BEFORE 15 OR AFTER 20 MINUTES as it may give an inaccurate result. If the test is done correctly, you should see one red dyed line at the “C” marker on the cassette which is the control line. If after 15 minutes, there is only a red line at the “C”, you have tested negative. If a second line appears at the “T” marker, you have tested positive for COVID-19. The test measures the amount of nucleoside cap proteins which is the protein that wraps around the virus’s genetic material. If enough of the protein is found in your nasal secretions, you get a positive result. The key word here is enough. The test has a threshold that the amount of protein must exceed in order to produce a diagnosis.

This is different than the more accurate PCR test which can boost the virus’s genetic material allowing it to be detected at earlier stages of the infection. As such, if you tested negative on this rapid test, there is a chance you could have COVID but still be too early in the infection to actually test positive.

The Omicron variant reproduces so rapidly that it has a much shorter incubation period than Delta did (1.5 to 3 days versus 5 to 6 days with Delta) and therefore the “window” for a false negative is much shorter. False positive tests are very rare. If it comes up with the double line (line on both the ”C” and “T”), you are 98 to 99% likely to have COVID. It should also be noted that the tests are specific for COVID and its variants.

If you have a cold or the flu, the test will come up with a negative result. There are no specific guidelines as to when you should test yourself but a good general rule is to do it when you feel unwell or when the results will change how you’re going to behave in the next 24 hours or so. An example of this is if you are trying to decide to visit an immuno-compromized loved one or to attend a social gathering.

Testing for curiosity’s sake is not ideal. While the tests are available to you for free, remember that eventually everything you get from the government is paid for by your taxes and the bill that will someday come due for COVID is already a whopper. Should you test negative for COVID but feel unwell, continue to isolate and retest again in 24 hours to see if the negative result was due to the fact that there just wasn’t enough of the COVID proteins to exceed the threshold.

We have two other quick updates to pass along with respect to COVID. As of February 18th, youth aged 12 to 17 (you must have turned 12 by the date of your scheduled injection) are now eligible for a booster dose as long as it has been at least 168 days since their second dose. The booster in this age group will be of the Pfizer brand only due to its lower risk of causing inflammation of the heart in comparison to the Moderna brand. Book online with the ministry’s website or the various pharmacy websites in the area.

Lastly, there was a new vaccine approved in Canada last week called Nuvaxocid which is made by a U.S. based drug manufacturer. It is a protein-based vaccine (i.e. not an mRNA one like Pfizer or Moderna) which is the first of its kind approved in Canada although it has already been cleared for use previously throughout Europe and a number of other countries. It is given in 2 doses, spaced 21 days apart and appears to be 90% effective at preventing symptomatic disease and close to 100% at preventing severe disease. The company is in the process of establishing a manufacturing facility in Montreal which will hopefully one day provide Canada to become more self sufficient when it comes to supplying us with vaccines. For more information about this or any other health related questions, contact your pharmacist.