Fourth doses of the COVID-19 vaccine don’t appear to offer significant protection against catching omicron according to a preliminary study conducted in Israel, the first country to authorize a second booster for its general population. Researchers announced the resultsMonday, around three weeks after fourth shots became widely available across the country.
T cell exhaustion
Cavaleri was likely referencing a concern that seeing antigens (like those provided by vaccines) over and over again can lead to T cell anergy or "exhaustion”, said Sarah Fortune, a professor at the Harvard TH Chan School of Public Health Department of Immunology and Infectious Diseases, in an email to DW.
"T cells become dysfunctional when they repeatedly see antigen in certain contexts — and the best studied of that biology are settings like HIV or cancer where the antigen is there all the time, not just repeated vaccination," she wrote.
While T cell exhaustion can be observed in cancer or HIV patients in response to some immune-based treatments, it's never been observed in humans in response to frequent COVID-19 vaccination.
https://www.dw.com/en/covid-do-multiple-...a-60447735
T cell exhaustion
Cavaleri was likely referencing a concern that seeing antigens (like those provided by vaccines) over and over again can lead to T cell anergy or "exhaustion”, said Sarah Fortune, a professor at the Harvard TH Chan School of Public Health Department of Immunology and Infectious Diseases, in an email to DW.
"T cells become dysfunctional when they repeatedly see antigen in certain contexts — and the best studied of that biology are settings like HIV or cancer where the antigen is there all the time, not just repeated vaccination," she wrote.
While T cell exhaustion can be observed in cancer or HIV patients in response to some immune-based treatments, it's never been observed in humans in response to frequent COVID-19 vaccination.
https://www.dw.com/en/covid-do-multiple-...a-60447735