The protection against COVID-19 conferred by vaccines fades over time. A new study conducted in Israel, a real life-size laboratory, indicates that the concentration of the level of antibodies decreases by about 40% in six months.
International researchers came to this conclusion by analyzing the level of neutralizing antibodies and anti-spicle IgG antibodies in some 5,000 people following their injection of a second dose.
In comparison, vaccines against measles, mumps or rubella see their effectiveness decrease by 5% to 10% each year.
The decline appears stronger in men, people over 65 and immunosuppressed individuals, read the findings of this research published in The New England Journal of Medicine. In this last category of patients, the decrease in antibody concentration amounts to nearly 70% in six months.
“Strategies to prolong immunity must be evaluated to protect the population against SARS-CoV-2 and its variants”, concludes the scientific article.
Many states, including Quebec, have already started a recall campaign for a third dose in the most vulnerable people. Israel has even already vaccinated millions of people with a third injection in its general population.
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