WWhen I was vaccinated against Covid-19, I felt a deep sense of relief: I no longer had to worry about catching the disease in person.
When I noticed mild, Covid-19-like symptoms two months later – stuffy nose, chest congestion and a stomach upset, I thought it was due to seasonal allergies. I was shocked a few days later when a test for Covid-19 in preparation for an unrelated medical procedure came back positive.
Because I do not believe the result, I tested again. And again. Over a period of five days, I underwent four PCR tests – two were positive, two were unconvincing – and a false negative rapid antigen test.
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I quickly proceeded to quarantine and notify recent contacts. I soon received several calls from the Health Council in my city, whose representative told me that she knows of other people who have also tested positive, even though they have been fully vaccinated.
My experience shows that the test for Covid-19 is not perfect. Rapid antigen tests detect proteins that are part of SARS-CoV-2, the virus that causes Covid-19. They have a fast throughput time, but are not as accurate as the gold standard PCR test. In people with Covid-19 symptoms, rapid tests can detect the virus correctly only 80% of the time. In those without symptoms it drops to 40%.
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PCR tests, on the other hand, tend to have much higher sensitivities, above 95%.
The way samples are collected can also affect the results of Covid-19 testing. I know this happens because I have had many Covid-19 tests over the past year. At some test centers, the clinician placed the swab at the very back of my nose, known as the nasopharyngeal space. Some say it feels like the swab is on its way into the brain. In other test centers, the clinician barely scraped the bottom edge of my nose; it is called a nose swab. It made me wonder if it collected any monster at all. I have since learned that nasal swabs can detect the virus in people with a low virus load.
Although vaccination essentially provides 100% protection against Covid-19 hospitalization and death, it does not prevent people from contracting the infection in the first place.
A recent study from the University of California, San Francisco, which tracked more than 30,000 health workers, showed an infection rate of about 1% after vaccination, meaning infection is rare but still a threat. The Minnesota Department of Health has announced that it is investigating several of these “breakthrough” cases, as well as the Oregon Health Authority. In mid-April, the Centers for Disease Control and Prevention reported 5,800 breakthrough infections among the millions of Americans who were fully vaccinated.
Reports of 95% efficacy in clinical trials with vaccines do not necessarily mean the actual effectiveness of that range, and may create a false sense of reassurance when it comes to asymptomatic or mild infections. The Pfizer trials only tested volunteers for SARS-CoV-2 if they developed symptoms after receiving the vaccine or placebo, and omitted those who were asymptomatically infected. Modern trials have also looked primarily at the prevention of symptomatic diseases.
The lower efficacy rates in the clinical trials of the J&J vaccine may be more real, as it includes asymptomatic PCR testing of participants, had more patient populations, and was done later in the pandemic, when more viral variants were identified. These differences may be responsible for the lower efficacy of this vaccine – 74% to prevent asymptomatic infections – compared to 80% for Pfizer and Moderna vaccines, according to a recent study by the Mayo Clinic.
Here’s what I think all this means.
No vaccine is 100% effective in preventing Covid-19. However, those we have are very effective in preventing serious diseases, death and reducing the virus burden in people who are unfortunate enough to contract breakthrough infections after vaccination. The focus should now be on getting as many people vaccinated as soon as possible – and tested so that we can end the pandemic as soon as possible. To do this, we need more streamlined access to vaccinations and tests.
Regardless of the vaccination status or previous infection, anyone with signs or symptoms of Covid-19 should be tested, as well as anyone who has been in close contact (within 15 meters or longer) with someone with a confirmed Covid-19. According to the CDC, people who have been fully vaccinated and have no symptoms after exposure need to be tested.
In Massachusetts, where I live and work, the Stop the Spread initiative and organizations like Transformative Healthcare make free Covid-19 testing more available.
At the federal level, the Biden government has already issued several executive orders to tackle the virus and expand Covid-19 testing for children and underprivileged populations, including a $ 650 million investment for K-8 schools and the homeless. shelters.
Even with nearly 25% of the American population fully vaccinated, I – and others like me – am proof that now is not the time to let our guards down. Vaccinations are necessary but not sufficient to address Covid-19. Get vaccinated but do not keep up with the wind regarding mask wear, basic hygiene and physical distance. Only when we establish herd immunity can we achieve our goal of eradicating this virus.
Stephen M. Tourjee is a child and adolescent psychiatrist; founder of Northshore Minds, a mental health practice north of Boston; co-director of Massachusetts General Hospital’s program for menopausal youth; and an instructor in psychiatry at Harvard Medical School.