Seniors | A fourth dose considered

After Denmark, Spain, Germany and Sweden, France has also decided to recommend a fourth dose of vaccine against COVID-19 for the elderly. Should Quebec do the same? Experts are studying the issue.

Posted at 5:00 a.m.

Eric-Pierre Champagne

Eric-Pierre Champagne
The Press

France follows suit

Since Saturday, French people aged 80 and over can receive a fourth dose of vaccine against COVID-19. The decision was taken after authorities noted a slight rebound in the epidemic in France, which is believed to be attributable to a sub-variant of Omicron, BA.2. This is more transmissible than Omicron, which was already more contagious than the Delta variant. The BA.2 sub-variant would not be more dangerous than Omicron. According to the French Prime Minister, Jean Castex, this recommendation does not call into question the lifting of the main health measures. The “sanitary pass” is no longer required in France since Monday. The mask is no longer compulsory in public places, except in public transport and health establishments.

And Quebec?

We will soon know if a similar recommendation will be made in Quebec. “The Quebec Committee on Immunization is discussing this subject and its opinion will be published next week,” said Dr.r Gaston De Serres, who is also an epidemiologist at the National Institute of Public Health. “We are indeed looking at the situation in Quebec, confirms Maryse Guay, professor at the Faculty of Medicine and Health Sciences at the University of Sherbrooke. There may be a recommendation in that direction. The epidemiology expert specifies that even if there is a decrease in all the indicators relating to the pandemic, we must remain cautious with the arrival of spring and the relaxation of sanitary measures.

Efficiency that decreases over time

“We know that the vaccine is effective overall but that immunity decreases over time. As we have a lot of doses available, why save the cost of protecting the most vulnerable? says Roxane Borgès Da Silva, director of the School of Public Health at the University of Montreal. If the situation improves in Quebec, the expert nevertheless warns that there are a few months left before arriving in the summer, a season when the population is less confined inside. On the other hand, there is the BA.2 sub-variant which must be taken into account. It is widespread in Europe, but is not yet dominant in Quebec.

“Minimal benefit” in young adults

According to an Israeli study published Wednesday, a second booster dose of current messenger RNA vaccines may provide only “minimal benefit” in healthy young adults. The study, performed when the Omicron variant was circulating widely in Israel, suggests that the fourth dose provides little additional protection against infection, despite the gradual decline in antibody levels in those who received three doses. Protection against symptomatic forms of the disease is slightly better than in those who received three doses: 43% with the Pfizer vaccine and 31% with that of Moderna. These results suggest minor benefits, but they should be taken with caution, given the small number of participants in the study, which was published in the New England Journal of Medicine.

Pfizer wants to get a second booster dose authorized in the United States

Based on data from Israel, Pfizer-BioNTech on Tuesday asked the U.S. Drug Administration (FDA) to authorize an additional booster dose of their COVID-19 vaccine for people 65 and older. . According to Pfizer-BioNTech, these data show that “an additional booster dose of messenger RNA vaccine increases immunogenicity,” that is, the ability to elicit an immune response, “and reduces infection rates. confirmed and serious illnesses”. In Israel, a fourth dose of the Pfizer vaccine has been administered since early January to those over 60, and since late January to those over 18 who are at risk. It can multiply the antibodies three to five times compared to the third dose, according to the Israeli Ministry of Health.

Ontario expects hospitalizations to rise

Ontario’s science advisers say COVID-19 hospitalizations and intensive care unit admissions will likely increase as public health measures are lifted, but believe they will remain far from levels seen at the peak of the Omicron wave. New modeling released Thursday by the Ontario Science Advisory Table – before mask-wearing requirements were lifted Monday in most settings – suggests that if there is a moderate increase in transmission of the COVID-19, hospitalizations will likely increase, even if they will not exceed 1000.

With Agence France-Presse and The Canadian Press


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