Studies reveal the best protection against Omicron
Three huge studies point towards the booster vaccine as the best way to avoid serious covid-19 symptoms.
The Omicron variant arrived at a time when many countries were already beginning to glimpse a way out of the pandemic. With its rapid transmission, cases soon began to skyrocket almost everywhere in the world. In Europe, Spain went from having a cumulative incidence per 100,000 inhabitants of just 42 cases, to more than 3,200 registered in recent days.
Faced with this rapid progress, the US rushed to inoculate a third booster dose of the vaccine, in anticipation of a drop in antibodies over the months. And according to three large studies published by the United States Centers for Disease Control and Prevention (CDC), this third dose represents the best possible protection against the new variant.
The researchers' data confirm the results of people immunized with the Pfizer and Moderna vaccines (both based on messenger RNA), and who have received the third dose. The first of the studies submitted by the CDC took a sample of 88,000 hospitalized patients in various states of the country. The booster dose showed an effectiveness of 90 percent in avoiding hospital admissions between December and January, when Omicron became prevalent.
The difference with respect to having received only the first two doses is remarkable, since there is only an effectiveness of 57 percent six months after the last jab. Finally, according to this study, the booster vaccine was 82 percent effective in preventing emergency care, compared to 38 percent of those who had received two doses.
With three doses, less risk of infection
According to the second of the studies, the probability of becoming infected with the Omicron variant is reduced with this third dose. The data was collected in a total of 25 states of the country and local health departments. Among those who had received the third dose, there were 149 weekly cases per 100,000 people; those that do not, 255 per 100,000 inhabitants.
The third study, cited by CNN and to be published soon in the Journal of the American Medical Association (JAMA), confirms that the third dose helps prevent people from getting sick from Omicron. In this study, 13,000 cases of this variant were taken as a reference: the possibility of developing a symptomatic infection is 66 percent lower for those who have received the third dose of the Pfizer and Moderna vaccines.
"I think we have to redefine the complete vaccination as three doses," says Dr. William Schaffner, vaccine adviser at the CDC, to the North American chain. For her part, the director of these centers, Rochell Walensky, assures that "those who remain unvaccinated are at greater risk of infection and serious illness."
Walensky highlights the fact that those who have a third dose are more protected against the Omicron variant, and regrets the high percentage of people who have rejected the third dose in the US when the new vaiant is so transmissible. "I urge all those who are eligible to receive the booster dose to do so as soon as possible."