Conflicting data over the effectiveness of a covid vaccine emerged today during the controversy over immunization of children.
Pfizer-BioNtech's study, released today, shows that a low dose of its vaccine is 90.7 percent effective in children aged 5 to almost 12. Yet a separate massive study of veterans, released Oct. 14, shows that the formerly effective covid vaccines have all fallen off dramatically in potency, with Pfizer-BioNtech's plummeting from more than 90 percent effective in March to about 50 percent by August.
Neither study has been peer reviewed.
Pfizer-BioNTech presented data from a study of 1,518 children who received the 10-microgram vaccine — one-third the adult dose — and another 750 who received a placebo. The vaccinated volunteers were 90.7 percent less likely to develop symptomatic covid, and when they did become ill, their symptoms were less severe, the researchers said.
Earlier today an FDA advisory panel urged emergency use of the vaccine on children.
Pfizer-BioNtech scientists had argued that earlier this year covid was one of the top 10 killers of children in the 5- to 12-year age range. The FDA's advisers felt that those children who are at risk should be permitted to have the vaccine. The drug company's study also pointed out that schoolchildren, who may not get sick, can carry the disease home. But StatNews reported,
It seems plausible that the aged and infirm were strongly represented among the veterans studied. Yet, during the early stage of the vaccination of veterans, effectiveness was reportedly high. Does this rule out immunological problems as a major factor in the drops in efficacy? Probably. Drops in efficacy are generally tied to virus mutations, such as the Delta variant, which, according to the a July statement of the American Society for Microbiology, was by then responsible for more than 83 percent of U.S. cases.
StatNews said,
But the Pfizer study reports that its vaccine was successful in 90.7 percent of children who had not previously shown any covid-like symptoms. That caveat may be meaningful, as it strongly tends to select in favor of altogether healthy children -- even though a fair representation would include some children who are not in excellent health. (Ethical problems may have entered the picture here.)
Pfizer-BioNtech research paper
https://www.fda.gov/media/153409/download
Cohn et al on vaccine potency drop
https://www.medrxiv.org/content/10.1101/2021.10.13.21264966v1
Cohn and her colleagues wrote,
Pfizer-BioNtech's study, released today, shows that a low dose of its vaccine is 90.7 percent effective in children aged 5 to almost 12. Yet a separate massive study of veterans, released Oct. 14, shows that the formerly effective covid vaccines have all fallen off dramatically in potency, with Pfizer-BioNtech's plummeting from more than 90 percent effective in March to about 50 percent by August.
Neither study has been peer reviewed.
Pfizer-BioNTech presented data from a study of 1,518 children who received the 10-microgram vaccine — one-third the adult dose — and another 750 who received a placebo. The vaccinated volunteers were 90.7 percent less likely to develop symptomatic covid, and when they did become ill, their symptoms were less severe, the researchers said.
Earlier today an FDA advisory panel urged emergency use of the vaccine on children.
Pfizer-BioNtech scientists had argued that earlier this year covid was one of the top 10 killers of children in the 5- to 12-year age range. The FDA's advisers felt that those children who are at risk should be permitted to have the vaccine. The drug company's study also pointed out that schoolchildren, who may not get sick, can carry the disease home. But StatNews reported,
Several panelists expressed concern about whether the decision could lead to vaccine mandates — something Peter Marks, the head of the FDA’s Center for Biologics Evaluation and Research, assured them was unlikely. At the beginning of the day, Marks said that thoughts about vaccine mandates should not impact the panel’s decision.The Pfizer-BioNtech study occurred sometime after July 16, when its study of teens and 12-year-olds ended. No specific start date for the child study is given, though a cutoff date of Oct. 8 is given. Hence the child immunizations occurred while the Pfizer vaccine's potency was on the decline among veterans.
It seems plausible that the aged and infirm were strongly represented among the veterans studied. Yet, during the early stage of the vaccination of veterans, effectiveness was reportedly high. Does this rule out immunological problems as a major factor in the drops in efficacy? Probably. Drops in efficacy are generally tied to virus mutations, such as the Delta variant, which, according to the a July statement of the American Society for Microbiology, was by then responsible for more than 83 percent of U.S. cases.
StatNews said,
The panel weighed the benefits of preventing covid against the risks of the vaccine, in particular the risk of the heart conditions myocarditis and pericarditis, which, though hard to measure exactly, appear to occur once per every 10,000 or so in vaccinated older boys and young men. The cases seen after use of the vaccine appear to be milder than regular cases of the inflammatory condition, and last for a shorter time.According to the study of veterans, which was carried out from Feb. 1 to Aug. 13, the effectiveness of full vaccination -- derailed by the rise of the Delta variant -- had plunged.
But the Pfizer study reports that its vaccine was successful in 90.7 percent of children who had not previously shown any covid-like symptoms. That caveat may be meaningful, as it strongly tends to select in favor of altogether healthy children -- even though a fair representation would include some children who are not in excellent health. (Ethical problems may have entered the picture here.)
Pfizer-BioNtech research paper
https://www.fda.gov/media/153409/download
Cohn et al on vaccine potency drop
https://www.medrxiv.org/content/10.1101/2021.10.13.21264966v1
Cohn and her colleagues wrote,
National data on COVID-19 vaccine breakthrough infections [infections after full vaccination] is inadequate but urgently needed to determine U.S. policy during the emergence of the Delta variant. We address this gap by comparing SARS CoV-2 infection by vaccination status from February 1, 2021 to August 13, 2021 in the Veterans Health Administration, covering 2.7% of the U.S. population. Vaccine protection declined by mid-August 2021, decreasing from 91.9% in March to 53.9% (p<0.01, n=619,755). Declines were greatest for the Janssen vaccine followed by Pfizer–BioNTech and Moderna. Patterns of breakthrough infection over time were consistent by age, despite rolling vaccine eligibility, implicating the Delta variant as the primary determinant of infection. Findings support continued efforts to increase vaccination and an immediate, national return to additional layers of protection against infection.
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