Why Should We Keep Testing After Vaccination?

 Over the past several months, hundreds of millions of people have received at least one dose of a COVID-19 vaccine. For businesses eager to re-open and put this pandemic behind them, this increase in vaccination rates is seen as a step in the right direction.  But if you’re currently offering Covid tests to your employees and clients, this might raise some questions. 

Will vaccines cause a positive test result? 

Vaccination against SARS-CoV-2 will not result in a positive PCR or antigen test, the two most commonly types of tests to diagnose a COVID-19 infection. Vaccinations have not been shown to interfere or reduce test accuracy.[1] 

PCR tests and antigen tests look for small portions of the COVID-19 virus. A PCR test detects the genetic material of the virus, while antigen tests detect a small piece of protein from the virus. Vaccines contain small parts of the virus, or in the case of an mRNA vaccine, the instructions for your muscle cells to create a small part of the virus. Vaccines work by showing your immune system a piece of the virus so it can learn how to recognize and fight COVID-19, should you be exposed to the live virus. The parts of the virus in a vaccine are not detected by PCR or antigen tests. 

However, you may get a positive test result with an antibody test after vaccination. This indicates that your body has responded correctly to the vaccine, as a sign you have developed antibodies and some level of protection against the virus. 

But why keep on testing? Aren’t vaccines effective? 

One of the main reasons to start or keep using rapid testing (either PCR or antigen) at your facilities is because not everyone is fully vaccinated yet.  Even in countries like Canada, where the vaccination rate is considered very high, at the time of publishing, 50.22% of Canadians are fully vaccinated, meaning that 1 in every 2 are not vaccinated.  A testing strategy helps protect your employees and customers who are not yet vaccinated, or who are unable to get vaccinated. 

The second reason is that no vaccine has 100 percent guaranteed immunity, there is still a chance, while small, that someone who is vaccinated could still get COVID-19.  Add to this the rise of new variants of concern. Our currently available vaccines might not have as much protection against these new variants as they do the original forms of the virus.[2] While much of the attention these days is on vaccination, its likely a combination of vaccinations and testing that will help our economy open not only more quickly, but also more safely.  

What type of test should I rely on? 

PCR testing is one of the most accurate ways to test for COVID-19.  But it takes time and you need a dedicated space, trained lab personnel, and nurses to ensure that the process is validated.   

Rapid antigen tests are an alternative to PCR testing and are a great fit for non-healthcare workplaces. They are promoted by the CDC and other medical advisory boards around the world as a way to control the spread of COVID-19.  Rapid antigen tests, such as the Sofia SARS Antigen FIA, are now being deployed in the fight against COVID-19, especially since vaccinations level are rising. 

Antigen tests are an effective tool to help employers prevent the spread of COVID-19 in the workplace. Antigen tests, when used for screening employees in non-healthcare workplaces, can detect current infection before an employee enters the workplace or returns to work.[3] To protect your employees and your production, you should consider continual testing.  The best, fastest, and most economical way to do continual testing is by using rapid antigen testing kits. 

Some rapid antigen tests, like the Sofia SARS Antigen FIA, can detect COVID-19 infections even in asymptomatic people, which can help to identify and isolate infections and reduce further spread. Public-health authorities consider these tests an important additional step on top of vaccinations, masks, and physical distancing. [4] 

“Getting that reassurance that it’s safe to go out and do business again and to engage in more ordinary activities is absolutely critical,” said Perrin Beatty, President of the Canadian Chamber of Commerce. “Rapid tests will play an important part in that.” 

If you are interested to learn more about rapid testing and how to protect your employees and maintain your productivity, reach out to us via email or call us at 1-888-444-7702.  We are now offering the Sofia SARS Antigen FIA by Quidel! If your organization is looking for an easy to use, highly sensitive antigen test that can provide COVID19 test results for asymptomatic individuals, look no further. 

We can help you achieve a safe workplace for your employees, customers, and visitors. 


[1] RACHEL WEST, GIGI KWIK GRONVALL, AND AMANDA KOBOKOVICH | FEBRUARY 2, 2021, John Hopkins Bloomberg School of Public health.

[2] What Covid-19 testing looks like in the age of vaccines Testing can do things for us now that it couldn’t do before. Sara Morrison, Recode,  Apr 1, 2021.

[3] Antigen Testing for Screening in Non-Healthcare Workplaces | CDC

[4] Irene Galea, Globe and Mail, July 9, 2021

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Founded in 2016, Precision Biomonitoring provides industry-leading expertise in molecular direction of organisms. Their very own TripleLock™ technology aims to deliver rapid, on-site environmental, food, animal and human diagnostic testing solutions. Customers are any organizations that need onsite surveillance and rapid identification of any organism in any environment. The Precision Biomonitoring team is at the forefront of technological innovations in the genomics industry. Our vision is a world where we can identify any organism on the spot, in an instant, anywhere on the planet.