Source: Arabic
The effectiveness of the booster dose of Pfizer and Moderna’s anti-coronavirus vaccines declines with time, but remains high in reducing the risk of hospitalization four months following receiving the dose, according to a study published by the US health authorities on Friday.
This efficacy was known following receiving two doses of the vaccine, but it has not been adequately studied following the third dose.
The study included 93,000 hospitalized patients and more than 240,000 visits to emergency centers related to corona in 10 US states.
It was conducted between the end of August 2021 and January 2022, and the two waves associated with the mutant included Delta and Omicron at the same time.
In the two phases, the effectiveness rate following the third dose was always higher than following the second dose, according to the Centers for Disease Control and Prevention (CDC), which published the study.
After Omicron became the dominant mutant, the effectiveness of the third dose in reducing hospitalization was 91% for those who received the booster dose within the two months prior to injury, but it decreased to 78% for those who received the booster four months or more before infection. Even this percentage “remains high”, according to the “CDC” centers.
Also, following the spread of the omicron mutant, the effectiveness of the booster dose in reducing going to the emergency was 87% in the following two months, 66% following four months, and only 31% following more than five months.
The Centers for Disease Control and Prevention stresses that the latest rates are “inaccurate” due to the limited number of people who participated in the study and received their third dose more than five months before infection.
“CDC” says that these results “increase the importance of taking into account the provision of additional doses in order to maintain or enhance protection once morest corona.”
And the White House adviser on the health crisis, Dr. Anthony Fauci, had confirmed during a press conference on Wednesday that it is possible that people who are more vulnerable to infection than others, such as the elderly or those with low immunity, need a fourth dose in the future.
