The Exploration Place team is proud to be a part of the Canadian Red Cross and Health Canada’s Stop the Spread and Stay Safe! program. The Government of Canada is providing free COVID-19 rapid antigen testing kits to support screening programs for personnel from charities, non-profits, and Indigenous organizations.
Screening programs like this are one way we can do our part to help stop the spread of COVID-19 and keep our team safe when they are working closely with one another and with the public. It is one more layer of protection on top of PCR testing, masks, hand hygiene, physical distancing, cleaning protocols, and vaccination. As well, regular screening gives us and the community greater confidence in the public programs we are providing and will help contribute to Canada’s collective COVID-19 response through reporting back of results.
Rapid antigen tests provide results very quickly—in as little as 15-20 minutes. However, they are less sensitive than the “gold standard,” the rt-PCR (reverse transcriptase polymerase chain reaction) tests administered to test for COVID-19. The two tests work in very different ways.
PCR tests are designed to look for and recognize a sequence of genetic RNA material specific to the COVID-19 virus. A PCR machine called a thermal cycler is used to amplify the RNA, putting the genetic material through heating and cooling cycles and replicating it until any present SARS-Cov-2 is detected. Special chemicals and enzymes are used, one of which produces a fluorescent light if the virus is present. Special software then interprets this signal. PCR testing will detect the presence of a virus if a person is infected and can also detect fragments of the virus even after someone is no longer infected. PCR testing was developed over 35 years ago and is used widely to test for many infectious diseases caused by viruses, bacteria, fungi, and parasites. Results can take hours, but depending on lab capacity, they may take several days or longer. It is incredibly accurate and reliable. The rate of false positives is very close to zero—probably less than 0.01%—and most of those result from lab contamination or human error, not the test itself. PCR tests developed for COVID-19 do not react to other viruses, even other coronaviruses. A new multiplex PCR test is now being recommended for COVID-19 testing, which will save money, time, and resources by testing for multiple viruses, such as influenza, at the same time as COVID, which can often have overlapping symptoms.
Rather than testing for RNA sequences like PCR testing does, antigen tests look for protein molecules on the virus’s surface. A sample taken from a nasal swab is mixed with a solution that releases specific viral proteins. This mixture is then applied to a strip containing a custom-developed antibody optimized to bind those proteins if they are present. The results are viewed on a device very similar to a home pregnancy test. The first rapid tests for COVID-19 were developed very early in the pandemic. They have, however, been vastly underutilized in Canada when they can work together with PCR testing to better control the spread of the virus.
Advantages are speed and relatively low cost. Despite a higher rate of false negatives, these tests are very effective at detecting positive cases. Rapid antigen tests are most useful as part of a frequent testing program and are not generally performed as a one-off. They are most often used to screen those without symptoms. Risk is reduced by testing people without symptoms regularly, which is not feasible with PCR testing. As part of a regular screening routine, rapid tests can help catch the virus before a person with a higher viral load has potentially spread it to others in the workplace.
If a team member receives a positive result from a rapid antigen test, they will then be directed to go for a lab PCR diagnostic test to confirm the result, allowing public health authorities to identify the nature of the virus and track variants of concern.
Rapid antigen testing is an important complementary part of the overall response, particularly in the North, where PCR lab results have been incredibly delayed. Many people are forgoing testing as a result of these delays, as potentially being off work for over a week is not possible for many. The point of testing is to get in front of transmission, which doesn’t work if people are not getting tested due to delays or are going about regular life because they don’t yet have a positive result. Deployment of rapid testing may not detect all positive cases, but it will catch the most contagious ones.
What made us decide to be a part of this program? For one, we are starting to add to our staff team, meaning more and more of us are working in the building together every day. We are also increasingly interacting more with the public by offering programs in the community—something that will ramp up quickly very soon. Finally, contributing to the data that will help shape the government’s response to the pandemic seems like a perfect opportunity to be part of the science—something central to our role as a science centre and as science communicators.
Following the science has always been a prime decision-making factor when it comes to us at the museum. Teaching and modelling scientific literacy, evidence-based decision-making, and critical thinking are at the forefront of our Mission and overcoming current challenges. In 2018, the Ontario Science Centre conducted a science literacy survey and found that “Science centres and museums rank first among Canadians’ most trusted sources of reliable scientific information. The vast majority of Canadians believe that science education is vital to solving critical challenges facing the world today.” That means science centres are more trusted than even scientists, doctors, and nurses. That is astounding but a role we take very seriously.
Taking part in programs like Stop the Spread! encourages us to further role model safe behaviours and communicate science to our community in a tangible and understandable way. We consider it one of our most important responsibilities to convey evidence-based information to the public, whether we’re talking about COVID-19 testing, vaccines, climate science, or history.
Science and technology are crucial in the control of this pandemic. It is astonishing how quickly those in science and tech have worked to develop effective testing, vaccines, and treatments. It is exciting to watch the speed with which scientists learn more about this virus and ways to respond to it. At The Exploration Place, we are excited to be a part of the data collection that will further inform the response while keeping our team and the public safer.