A recent study soon to be published in the Journal of Medical Biochemistry found that Pfizer/BioNTech’s experimental messenger RNA (mRNA) BNT162b2 biologic for COVID-19 significantly loses its efficacy within six months of the second shot. Researchers from the University of Verona in Italy and Cincinnati Children’s Hospital Medical Center in Ohio looked at 787 health care workers in Verona, Italy between the ages of 21 and 75 years old and found that their SARS-CoV-2 virus antibody levels had dropped by 57 percent six months after the second dose of the biologic.1 2
Initial studies of BNT162b2 by Pfizer and BioNTech last year estimated the efficacy of the biologic to prevent serious symptoms of COVID disease at 95 percent. A “real world” study of 4,000 health care workers conducted by the U.S. Centers for Disease Control and Prevention (CDC) earlier this year suggested that the effectiveness of BNT162b2 was closer to 90 percent. Based on the data gained from the new Italian study, the efficacy of the biologic is estimated to be about 33 percent.1 3 4
In August, Pfizer and Kaiser Permanente released a study, of the electronic health records of about 3.4 million people who had received two doses of BNT162b2. The study, which was subsequently published in the medical journal The Lancet, estimated BNT162b2’s efficacy at 47 percent six months after the second shot.5 6
Another recent study conducted by researchers from the Public Health Institute in Oakland, California the Veterans Affairs Medical Center in San Francisco and the University of Texas Health Science Center estimated the efficacy of the biologic at 45 percent after six months. That study was published in the journal Science.6
Serious Decline in COVID Vaccine Antibody Levels Affects All Age Groups
The participants in the Italian study had their antibody levels measured prior to their first shot, immediately after their second shot, and then again at one, three and six months after their second shot. Researchers found that antibody levels declined by more than 50 percent for both males and females and across all age groups. But women did show higher antibody levels than men, and participants under the age of 65 maintained higher levels than those over 65.1 2
According to Brandon Michael Henry, MD, who is a co-leader of study, the difference in antibody levels between genders could be caused by hormones. Typically, males have more testosterone, which has a suppressing effect on the immune system, while females normally have more estrogen, which enhances the immune system.1 7 8
Additionally, Dr. Henry thinks that chromosomes may play role. The X chromosome has specific genes associated with immunity, and women have two X chromosomes, while men have one X chromosome and one Y chromosome. “Normally, only one X chromosome is active, and the other is mostly deactivated, but there is evidence that immune-related genes stay active on that redundant chromosome and help boost immune responses in women,” Dr. Henry said.1 9
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Click here to view References:
1 Huzar T. Antibodies from COVID-19 vaccine may reduce by 57% after 6 months. Medical News Today Nov. 26, 2021.
2 Salvagno GL et al. Total Anti-SARS-CoV-2 Antibodies Measured 6 Months After Pfizer-BioNTech COVID-19 Vaccination in Healthcare Workers. SSRN September 2021.
3 Branswell H. ‘Real world’ study by CDC shows Pfizer and Moderna vaccines were 90% effective. STAT Mar. 29, 2021.
4 Press release. Pfizer and BioNTech Conclude Phase 3 Study of COVID-19 Vaccine Candidate, Meeting All Primary Efficacy Endpoints. Pfizer Nov. 18, 2021.
5 Mishra M. Pfizer/BioNTech COVID-19 vaccine effectiveness drops after 6 months, study shows. Reuters Oct. 4, 2021.
6 Ellis R. COVID Vaccines’ Protection Dropped Sharply Over 6 Months: Study. WebMD Nov. 5, 2021.
7 Taneja V. Sex Hormones Determine Immune Response. Front Immunol Aug. 27, 2018.
8 MedlinePlus. How many chromosomes do people have? National Library of Medicine.