COVID Paper Database
COVID-19 Booster Shots
COVID-19 Boosters in Adults 60+
Does the Pfizer booster help boost immunity?
Reviewed by Charles Li, MD
April 21, 2023
Summary
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Question- Does a third dose of the Pfizer vaccine help older adults?
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Method- 97 individuals were tested before and after their booster shot.
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Result - Booster shots dramatically increased antibody levels against COVID-19 and led to 100% seropositivity
Visual Abstract
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Background
After 6 months, your protection from COVID-19 with two doses of the Pfizer vaccine begins to decline. This effect is especially strong in adults older than 65.
Researchers in this study wanted to see whether a third "booster" dose of the Pfizer vaccine improved immunity against COVID-19 in older adults.
Study Quote
The durability of response to the SARS-CoV-2 BNT162b2 vaccine (Pfizer-BioNTech) in adults aged 60 years and older has yet to be determined. The immune response to 2 doses of BNT162b2 is lower in individuals aged 65 to 85 years vs 18 to 55 years. Among 4868 health care workers receiving 2...
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Study Design
Researchers studied the effectiveness of a booster shot by measuring COVID-19 antibodies before and after individuals received a third dose.
There were 97 participants in this study, all age 60 and older.
Researchers analyzed blood samples that were drawn before and after a third dose was given.
Researchers measured the amount of COVID-19 protective antibodies in the blood samples to measure the effect of the vaccine.
Study Quote
We assessed antispike (anti-S) IgG antibody titers before and after a third BNT162b2 dose in individuals aged 60 years and older because this population is at high risk of developing severe SARS-CoV-2 disease and was the first to receive authorization for a third dose...After the initial...
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Results
In a study of 97 older adults, researchers observed that antibodies protecting against COVID-19 increased dramatically after they received a third dose of the COVID-19 vaccine.
Before receiving the third dose, most had some antibodies providing protection against COVID-19, but at relatively low amounts.
After receiving the third dose, participants experienced a dramatic increase in their COVID-19 antibody levels.Ā
Since antibodies are what our bodies use to protect COVID-19, this suggests that a third dose did indeed increase protection against COVID-19.
Additionally, 3% of individuals did not have significant protection against COVID-19 before their third dose, as measured by their antibodies against COVID-19.Ā
After the third dose, 100% of participants had antibodies and protection against COVID-19.
There were no major side effects reported in the study.
Study Quote
Among the 97 study participants, the median age was 70 years (IQR, 67-74), and 61% were women (Table 1). Before the third dose (median, 221 days [IQR, 218-225] after the first vaccination), 94 participants (97%) were seropositive. The median titer level increased significantly after the ...
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Discussion
This study showed that a third dose of the Pfizer vaccine significantly boosts antibody levels in adults ages 60+ with no major side effects.
These data are consistent with several other studies that have shown immunity benefits with a third vaccine dose.Ā
The authors did note that the study had several shortcomings. It was a relatively small study with less than 100 participants. The study also did not perform tests to see whether the detected antibodies were neutralizing antibodies.
This study adds more evidence that booster shots can be effective in providing more protection against COVID-19.
Study Quote
This study found that a third BNT162b2 dose in adults aged 60 years and older was associated with significantly increased IgG titers after 10 to 19 days, with no major adverse events...
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Researchers found that a third dose of the Pfizer vaccine dramatically increased antibodies protecting against COVID-19 among adults ages 60+. Vaccination also increased seropositivity, the number adults with protection against COVID-19, from 97% prior to the third dose to 100% after the third dose. Researchers concluded that a third dose significantly boosts antibodies and immunity in older adults.