Some experts are already predicting a “bushfire” and increased hospitalizations, faced with the lightning advance of the Omicron variant against which the double vaccine would no longer be an effective weapon to prevent millions of Quebecers from being infected.
Already responsible for 20% of cases of infections in Quebec, according to screening data revealed Thursday, the Omicron variant risks bringing us back to the equivalent of a “first wave”, where the majority of the population is found almost without immunity against the risk of infection, insisted Thursday Benoît Mâsse, epidemiologist at the School of Public Health of the University of Montreal, before Quebec announces new measures to slow down the pandemic.
“People need to realize that we end up almost like in December 2020, when no one was vaccinated, because Omicron can infect, even with two vaccines. If we have nothing to stop it, we will taste it. Our models already predicted 500 hospitalizations just with the Delta, ”he says.
The first data from the UK show a reduced protection to 30% or 40% against infections due to Omicron with RNA vaccines. But in the field, the data from Montreal rather show infections in people twice vaccinated, in 90% of cases. “If 100,000 people can be infected, rather than 1000, that will necessarily be reflected in hospitals,” adds the epidemiologist.
The big unknown remains Omicron’s ability to evade the protection against serious infections conferred by vaccines. So far, scarce data shows very few hospitalizations and even fewer deaths.
70 times faster
“If the variant can infect both vaccinated and unvaccinated people, we’re going to experience a huge wave soon, with fewer severe cases. But taking into account the number of people affected, there will be a possible congestion of hospitals ”, assesses Benoît Mâsse. The latter predicts that the detection capacity of the public health network will be quickly exceeded and that it will be difficult to take the real count of the number of people affected.
As for the risk of contagion, it would be extremely high according to a new study from the University of Hong Kong, conducted in the laboratory, showing that the variant can multiply 70 times faster in the upper respiratory tract than the Delta variant or previous strains. virus.
“That would explain his very great contagiousness. With a reproduction factor estimated between 4 and 9, it is much more contagious than influenza or the initial strain of SARS-CoV-2 (around 2). Going to a restaurant without a mask gives you little chance of escaping it. It’s going to be a bushfire, ”adds the epidemiologist. By way of comparison, a reproduction factor of 4 to 9 compares to the contagiousness observed for certain childhood diseases such as mumps, polio or smallpox.
The Montreal Regional Directorate of Public Health, which on Thursday closed three new schools, bringing the total to six, to halt Omicron’s progress, expects the number of cases due to the new variant to double every 2-3 days. As of Thursday, 949 cases of COVID-19 were detected in the metropolis, an increase of nearly 100% in one week. The screening carried out by the Laboratoire de santé publique du Québec of the 1,747 cases detected in Quebec on Tuesday shows that 20% are already linked to the new variant.
Flatten the curve, again
Even if Quebec announces a tightening of health measures at 6 p.m., experts believe that the outbreak will be difficult to slow down quickly. Despite the school break for children and workers for the holiday season, the models unveiled Thursday by the National Institute of Excellence in Health and Social Services (INESSS) predict a peak in hospitalizations in January if gatherings are allowed between on December 23 and 27, and “continuous transmission” if more gatherings are permitted.
In this context, “flattening the curve” by significantly reducing contacts remains the only rapid option to curb the progression of Omicron, believes Dr. Jesse Papenburg, researcher at the Center for Infectious Diseases of the McGill University Health Center (MUHC ) and member of the National Advisory Committee on Immunization (NACI).
COVID-19 Hospitalization Forecast with Omicron
“The variant is more transmissible, so you have to act very quickly. We must limit social interactions. Unfortunately, we have to go back to the good old concept of flattening the curve, ”he insists.
The new profile of the Omicron variant could also call into question the very validity of the vaccine passport, the capacity of doubly vaccinated people to contract this variant and to infect others is now high, he emphasizes.
This breach created by Omicron in the protection against infections militates for the rapid granting of a third dose to the greatest number, capable of increasing to 70% the protection against symptomatic infections, adds this specialist in respiratory diseases. “Omicron escapes the immunity against infection conferred by vaccines, but also immunity in people who have already been ill,” he says.
Granting a third dose depends not only on the goodwill of the population, but also on the logistical capacity of the government. On Tuesday, 500 vaccinators were missing to strengthen vaccine capacity in Quebec. On Thursday, the Ministry of Health said it had received 830 new applications on the Jecontribue platform.
with Marie Eve Cousineau