Three years of pandemic | COVID-19 still in the air

Three years after the start of the pandemic, COVID-19 has not said its last word. It remains present in Quebec, although it is discreet. Advances in science have made it possible to limit its impact, but the threat of new variants still looms large.

The threats still real

Healthcare centers still fragile

Certain measures, which would nevertheless make it possible to avoid the transmission of various respiratory diseases, are still slow to be implemented in health establishments and CHSLDs. “Having individual rooms decreases transmission. However, we make seniors’ homes which are magnificent, but after that, in CHSLDs, there are still rooms for two, ”laments the D^r Quoc Nguyen, geriatrician at the University of Montreal Hospital Center (CHUM). It is also essential to have enough staff in the care centres, he argues.

On the other hand, we have progressed insofar as the pandemic has made it possible to better understand “the importance of infection control in healthcare centers”, says the D^r Nguyen. “I see that everyone is paying more attention to the potential for disease transmission”, in particular by avoiding going to work when you are sick. “Workers are an important vector of disease transmission. We learned that the hard way during the pandemic. Wearing a mask has also been widely adopted in health centers.

COVID-19 is everywhere

Unlike influenza, which causes sudden spikes before disappearing for months, COVID-19 remains ubiquitous. This is evidenced by the positivity rate of screening tests, which has been hovering around 10% for months.

Although the impact of COVID-19 on hospitals is much less severe than at the start of the pandemic, there are still nearly 450 Quebecers hospitalized due to COVID-19, a number that has remained stable for months. COVID-19 continues to cause three to five deaths per day, enough to remain among the leading causes of death. More than car accidents or suicides.

That said, Quebecers are much less concerned about the disease. Moreover, for a year now, no less than 9 out of 10 people believe that the worst of the crisis is now behind us, according to polls conducted by the National Institute of Public Health of Quebec (INSPQ).

The long COVID-19 remains a mystery

Currently, thousands of Quebecers have long-term COVID-19, as they live with symptoms for months or even years after being infected with the virus. However, no specific treatment exists to treat them and the diagnosis remains difficult to make. “We still have a lot to learn about [du déclenchement de la maladie] to improve care,” says Dr.^D Emilia Falcone, who set up the Montreal post-COVID-19 research clinic at the Montreal Clinical Research Institute (IRCM).

Since the start of the pandemic, however, knowledge about this disease has evolved. Now, there is a much better understanding of risk factors, the impact of vaccination and variants on the risks of suffering from long-term COVID-19, symptoms and prevalence, lists the D^D Falcone.

Herd immunity will not happen

“At the very beginning of the pandemic, there was hope of developing collective immunity. We are aware today that the concept of collective immunity will not materialize, ”says Alain Lamarre, professor-researcher specializing in immunology and virology at the National Institute for Scientific Research (INRS). Herd immunity occurs especially when a sufficient proportion of the community is vaccinated and the vaccine limits transmission. People who do not receive the vaccine are then indirectly protected by others.

In the first three years of the pandemic, we still learned “a lot of things in terms of immunity”, argues pediatrician Caroline Quach, microbiologist and infectious disease specialist at CHU Sainte-Justine. “We now know that so-called hybrid immunity is the best and allows us to be much better protected against severe infections,” she says. This hybrid immunity, induced by both vaccination and infection with the virus, generally protects against serious infections for more than a year, says Lamarre.

The progress

Medication

The care offered to patients with COVID-19 has evolved a lot since March 2020. “At the start of the pandemic, there was no treatment,” recalls Jean-François Tessier, pharmacist at Maisonneuve-Rosemont hospital. Progress, however, has been rapid. “As early as May 2020, we had the first drug, remdesivir, which proved to be beneficial for patients who had COVID-19 pneumonia and who were hospitalized,” he says. In early 2022, the drug Paxlovid, which reduces the ability of the virus to replicate and slows the progression of the disease, arrived in Quebec. “We were the first province to allow this drug to be prescribed without having an appointment with a doctor,” rejoices Mr. Tessier.

However, some treatments are now proving ineffective. This is the case of monoclonal antibodies, which began to be used in the winter of 2021. These treatments, which neutralize the S protein of the coronavirus, “have lost their effectiveness [à cause des mutations présentes chez les nouveaux variants]and now we can’t really use them anymore,” laments Mr. Tessier.

The vaccine

Scientific advances have turned the course of the pandemic upside down, for the better. COVID-19 vaccine ‘probably the best news of the pandemic,’ says Dr^D Quach. In less than a year, scientists have developed an effective vaccine to limit the severe forms of the disease and which can be adapted quickly according to the evolution of the viruses, supports Mr. Lamarre.

However, with the appearance of new variants, the vaccine has not proven effective in limiting the transmission of COVID-19 in the population, as had been hoped. “The virus continues to circulate and mutate and it could eventually reappear as an even more contagious and potentially more virulent variant,” explains Lamarre. To prevent such a scenario from happening, researchers around the world are working to develop new types of vaccines and other ways to deliver it in aerosol form, intranasally or orally.

With Pierre-André Normandin, The Press