Studies Confirm Pfizer Vaccine Immunity Wanes At 2 Months
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.
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.
“Published work about many vaccines, such as those against measles, mumps and rubella, has shown a small decrease each year of 5% to 10% in the neutralizing antibody levels,” researchers wrote. “We found that a significant and rapid decrease in humoral response to the BNT162b2 [Pfizer/BioNTech] vaccine was observed within months after vaccination.”
A second study from Qatar looked at actual infections among the nation’s highly vaccinated population, who mostly received Pfizer’s COVID vaccine.
Estimated effectiveness against SARS-CoV-2 infection was negligible for the first two weeks after the first Pfizer dose, increased to 36.8 percent in the third week after the first dose, and reached its peak at 77.5 percent in the first month after the second dose.
Pfizer has consistently claimed the company’s own efficacy data demonstrate 95 percent efficacy against SARS-CoV-2, which was not observed in this study.
The researchers said effectiveness declined gradually, starting from the first month after the second dose, accelerated after the fourth month and reached a low level of approximately 20 percent in months 5 through 7 after the second dose.
The authors of the Qatar study, Laith Abu-Raddad of Weill Cornell Medicine-Qatar and colleagues, wrote:
“BNT162b2-induced protection against infection builds rapidly after the first dose, peaks in the first month after the second dose, and then gradually wanes in subsequent months. The waning appears to accelerate after the fourth month, to reach a low level of approximately 20 percent in subsequent months.”
At of the end of the study (Sept. 5), a total of 8,203 SARS-CoV-2 Pfizer breakthrough infections had been recorded among 947,035 participants who received one vaccine dose, and 10,543 breakthrough infections had been recorded among 907,763 participants who received two doses.
The percentage of all daily SARS-CoV-2 breakthrough infections from both Pfizer and Moderna reached 36.4 percent on Sept. 5, with 77.2 percent of breakthrough infections attributed to Pfizer’s COVID vaccine.
Pfizer-Funded Study Shows Vaccine Efficacy Declines At Six Months
A Pfizer-funded study published Monday in The Lancet found the efficacy of the Pfizer/BioNTech COVID vaccine fell below 50% about six months after the second dose.
The study found Pfizer’s vaccine was 88 percent effective in the first month after full vaccination but dropped to 47 percent effectiveness at about six months.
The study also found the vaccine to be “highly effective” against the Delta variant, which was found to be more than 90 percent effective in the first months before dropping to 53 percent effective after four months.
Researchers determined the waning immunity had to do with the amount of time since an individual was given the second shot, rather than due to the highly infectious Delta strain, The Hill reported.
“Our results provide support for high effectiveness of [Pfizer-BioNTech COVID-19 vaccine] against hospital admissions up until around 6 months after being fully vaccinated, even in the face of widespread dissemination of the Delta variant,” the researchers wrote.
“Reduction in vaccine effectiveness against SARS-CoV-2 infections over time is probably primarily due to waning immunity with time rather than the Delta variant escaping vaccine protection,” they added.
For the study, researchers looked at the 3.4 million electronic records from the Kaiser Permanente Southern California (KPSC) healthcare system for patients ages 12 and up, and studied them from December 2020 to August.
Researchers determined individuals fully vaccinated with the Pfizer-BioNTech vaccine had an overall 73 percent effective protection against COVID infection and 90 percent effective protection against COVID-related hospitalization.
Pfizer Asks FDA To Authorize COVID Vaccine For Emergency Use For Children Ages 5 To 11
Pfizer and its German partner, BioNTech, today asked the U.S. Food and Drug Administration (FDA) to authorize their COVID vaccine for emergency use for children 5 to 11 years old.
According to The Washington Post, an FDA advisory committee is scheduled to meet Oct. 26 to discuss Pfizer’s pediatric COVID vaccine.
FDA officials said once vaccine data for younger children was submitted, the agency could authorize a vaccine for younger children in a matter of weeks — not months — but it would depend on the timing and quality of the data provided.
Pfizer and BioNTech submitted initial data to the FDA last month for a regimen of two 10-microgram doses in children — one-third the amount given to older patients — but had not formally requested authorization until now.
According to Alex Berenson, former New York Times reporter and author of 12 novels and two nonfiction books — and currently author of the Substack publication “Unreported Truths” — said Prizer’s clinical data of its COVID vaccine for 5- to 11-year-olds showed no evidence of actual health benefit to the children who received it.
“In other words, what Pfizer demonstrated in its 2,300-patient child trial is that its mRNA doses can make your kids make spike proteins (and have side effects), Berenson said.
“Per Pfizer’s Sept. 20 press release announcing the trial’s results, the trial didn’t show the vaccine reduced hospitalizations (which are basically non-existent in healthy children) or even mild cases,” Berenson said.
Nowhere in Pfizer’s press release did it say the vaccine did anything to make kids stay healthier, Berenson explained. “But it did reveal side effects generally comparable to those observed in participants 16 to 25 years of age,” he said. “In other words, (sometimes severe) headaches, fatigue and fever.”
“Clinically significant myocarditis?” Berenson asked. “Who knows? With barely 1,000 boys receiving the vaccine, even fairly common side effects could go unnoticed.”
Maya Sen, a political scientist and professor at Harvard commented on the news: “It’s interesting to see people who all along have said that COVID isn’t that big of a deal for kids immediately pick up on the Pfizer research design as being supporting evidence of that,” Sen added.
Matthew Yglesias, writer, editor and senior fellow at the Niskanen Center responded: “Serious cases are so rare in children that it’s extremely hard to do a trial with sufficient statistical power to tell if you are preventing them.”
Jeff Zients, the White House COVID response coordinator, called Pfizer’s pediatric vaccine filing “an important development.”
Zients, appearing Thursday on CNN, said the country has the supply to quickly distribute the shots once the FDA and Centers for Disease Control and Prevention approve it.
Zients said the Biden administration is working with states to make it easy for parents to immunize their children by setting up convenient times and places to administer the shots.