An American study was carried out to estimate the time of protection conferred by the vaccine.
How long are people who have received their 3rd injection of messenger RNA vaccine protected once morest Covid-19?
In an attempt to answer this very useful question to determine the duration of the vaccine and to know if it may be necessary to proceed to a 4th dose, the United States Center for Disease Control and Prevention, the CDC, has launched a study to estimate the time of this vaccine-related protection.
A study to determine the durability of protection following three doses of vaccine
For this, data from fifteen medical centers located in 10 different states concerning nearly 100,000 hospitalizations were collected and analyzed.
The study highlighted all the consultations related to Covid, from a visit to the emergency room to a hospitalization between August 2021 and January 2022, as reported future.
In the CDC report published this Friday, February 11, it is specified that the effectiveness of the vaccine with regard to consultations related to Covid was higher following the third dose than following the second dose.
But the effectiveness still decreased following a few months following vaccination.
Significant decrease following four months
During the predominance of the Omicron variant, the researchers who studied the data, established that the vaccine immunity oftwo months following the injection of the third dose protected up to 87% for ER admission and of 91% for ICU admissions.
But the latter decreased following four months with a protection of 66% for emergency room admission and 78% for intensive care.
This decrease in vaccine effectiveness has also been observed in Israel and in other studies, the CDC report points out.
A reduction to put into perspective, a simple estimate
The report states that its results are a simple estimationbecause it only relies on cases that resulted in hospitalization, not those that avoided hospitalization.
So the duration of the efficacy on people with asymptomatic or mild symptoms is not taken into account in this study.
In addition, this estimate does not take into account health problems and especially the state of patients before their infection, some immunocompromised are more likely to be infected than others, nor does it respect barrier gestures. and behaviors in the face of Covid.
A study that encourages vaccination
Despite the fact that this study demonstrates a decrease in efficacy following four months for the 3rd dose, it also highlights vaccine effectiveness and in particular the booster vaccination with this additional allocated dose, which allows a fairly effective vaccination immunity.
Moreover, the scientists who wrote the study do not exclude the possible need for a extra dose if needed.
Towards a fourth dose? For the moment, this 4th dose is being considered in France and can only concern vulnerable populations if the epidemic figures decrease.
