excalibur
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- Mar 19, 2015
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From studies in the NEJM and from Israel.
childrenshealthdefense.org
Two studies published Wednesday in the New England Journal of Medicine confirm any immune protection offered by two doses of Pfizer’s COVID vaccine drops off after roughly two months — although protection against severe disease, hospitalization and death remains strong, the authors of the studies said.
A prospective longitudinal study from Israel covering 4,800 healthcare workers showed antibody levels waned rapidly after two doses of vaccine “especially among men, among persons 65 years of age or older and among persons with immunosuppression.”
Antibodies were tested during the baseline period defined as four to 17 days after receipt of a second vaccine dose, and every four weeks thereafter over a six-month period.
The highest titers after receipt of the second vaccine dose were observed during days four through 30, so this was defined as the peak period.
Because researchers could not perform neutralizing antibody assays in all study participants, they selected a subgroup that included higher proportions of persons with risk factors of interest, such as an age of 65 years or older and coexisting conditions.
The researchers noted that levels of so-called neutralizing antibodies — the immune system’s first line of defense against infection — correlate with protection against infection, but for this study researchers studied only antibody levels, CNN reported.
Researchers also saw a substantial reduction in the IgG level each month, and a significant decrease in neutralizing antibody titers.
...
A prospective longitudinal study from Israel covering 4,800 healthcare workers showed antibody levels waned rapidly after two doses of vaccine “especially among men, among persons 65 years of age or older and among persons with immunosuppression.”
Antibodies were tested during the baseline period defined as four to 17 days after receipt of a second vaccine dose, and every four weeks thereafter over a six-month period.
The highest titers after receipt of the second vaccine dose were observed during days four through 30, so this was defined as the peak period.
Because researchers could not perform neutralizing antibody assays in all study participants, they selected a subgroup that included higher proportions of persons with risk factors of interest, such as an age of 65 years or older and coexisting conditions.
The researchers noted that levels of so-called neutralizing antibodies — the immune system’s first line of defense against infection — correlate with protection against infection, but for this study researchers studied only antibody levels, CNN reported.
Researchers also saw a substantial reduction in the IgG level each month, and a significant decrease in neutralizing antibody titers.
...
Studies Confirm Pfizer Vaccine Immunity Wanes at 2 Months, as Pharma Giant Seeks FDA Approval for Kids 5 to 11
A study from Israel covering 4,800 healthcare workers showed antibody levels waned rapidly after two doses of Pfizer’s COVID vaccine. Meanwhile, Pfizer today officially asked the U.S. Food and Drug Administration to authorize its vaccine for children 5 to 11 years old.
childrenshealthdefense.org
