Pfizer COVID-19 Vaccine Associated with Dramatic Decline in Antibody Protection Just Weeks After 2nd & 3rd Dose

by | May 15, 2022 | Featured, Vaccines

Danish physicians and scientists affiliated with that Nordic nation’s prestigious Statens Serum Institut in Copenhagen and Zealand University Hospital in Naestved report that a study involving 128 patients published in the peer-reviewed JAMA Network Open reveals a troubling vaccine effectiveness finding associated with the Pfizer’s COVID-19 mRNA-based vaccine, BNT162b2. The results of this study suggest a dramatic decline in protection, and given mounting Omicron-based surges, more calls for booster doses for vulnerable populations. Investigating the impact of two and three mRNA-based does on 128 people, the Danish physician-investigator-based team found levels of omicron-specific “neutralizing” antibodies waning in strength after the second and third Pfizer jab. Unfortunately, within weeks the jab antibody levels meant to protect the individual from infection and severe disease wane within weeks and correspond with other studies reported by this media showcasing subpar performance and vaccine durability when compared to applicability to other COVID-19 variants, such as delta.

This study was conducted by the Statens Serum Institut, an institute under the Danish Ministry of Health, and the data derives from ongoing national infectious disease surveillance activity using excess biological material made available under Section 222 of the Danish Health Act.

The Study

In a cohort observational study, the team of scientists and doctors affiliated with Copenhagen’s prestigious Statens Serum Institut as well as Zealand University Hospital investigated the impact of the Pfizer mRNA vaccine known as BNT162b2 on individuals in Denmark who received two (2) or three (3) doses regimens between January 2021 and October 2021 as well as analyzing those who were previously infected prior to February 2021 and then vaccinated. This research followed Danish privacy and data protection laws and didn’t require ethical review nor patient consent.

The team determined 50% serum neutralization titers employing live virus microneutralization assay and used paired and non-paired quantitative measurements for comparison using the Wilcoxon matched-pairs signed-rank test and Mann-Whitney Utest, respectively, as reported by the authors in JAMA Network Open. Spearman correlation analysis was employed to find associations between continuous variables. The study team followed a reporting guideline known as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE).


As reported in JAMA Network Open, the observational study included 128 vaccinated persons in Denmark, including 73 who received two (2) doses and 55 who received 3 doses.

In the two-dose group, the median age was 51 years; 43% were males, while in the three-dose group, the median age was 70, with 38.9% of the male gender who received the dose 4 to 9 months after the second dose median ([IQR]: 6.9 [6.2-7.5] months).

A total of 7 “infected-then-vaccinated individuals” were male and between the ages of 47 to 65 years of age (median [IQR]: 57 [53-62] years). The study authors note that after four weeks post the administration of the second Pfizer COVID-19 vaccine dose, “neutralization geometric mean titers (GMTs) against the Omicron variant measured 14-fold lower compared with GMTs against D614G (P < .001).”

The following charts from JAMA Network Open report on the temporal virus-neutralizing antibody response against ancestral SARS-CoV-2 strain (D614G), Delta variant (B.1.617.2), and Omicron variant (B.1.1.529, BA1).

The data reveals a rapid decline in vaccine effectiveness when compared to performance against the ancestral SARS-CoV-2 strain (D614G) and the Delta variant when measuring BNT162b2 neutralizing antibody responses.

 Week 4Week 8 to 10Weeks 12-14
Decline in detectable Omicron-specific neutralizing antibody responses76% decline (16 of 21 individuals)53.3% (16 of 30 individuals)18.9% (3 of 16 individuals)

What about a third dose of BNT162b2? GMTs against Omicron grew 20.6 -fold by week 3 and 7.7-fold by week 4 as compared with GMTs after dose 2 at week 4 (P < .001).

While the third booster dose of BNT162b2 did, in fact, lead to greater neutralizing antibodies in most of the individuals covered in the study for approximately 8 weeks (2 months), this performance waned markedly, starting just a few weeks after BNT162b2 booster administration.

For example, the authors note by week 3 and week 8, “neutralizing antibody GMTs declined by 4.9-fold for D614G, 5.6-fold for Delta, and 5.4-fold for Omicron.”

What about stratifying for age? The Danish authors report differences based on whether an individual is above/below 65 years of age after the second dose (P = .02). However, this wasn’t the case for dose 3. The authors report that for five of the individuals over the age of 65 and included in this study, after the third dose and by week 8, any Omicron-specific GMTs were undetectable for two of the persons and low (GMT: 30-39) for three of the persons.

Summary of Findings

Omicron-specific neutralizing antibodies decline rapidly after both a second and third dose of Pfizer’s BNT162b2.

These antibody levels, critical for protection against SARS-CoV-2 infection and disease, reduced within weeks of the BNT162b2-based jab.

BNT162b2 performance declines markedly (as measured by antibody levels) against Omicron when compared against the original and Delta variants. The vaccine was developed against the original strain, and Omicron, of course, represents a significant different strain from that original based on ongoing mutation.

The drop in Omicron-specific antibodies is material—from 76% after four weeks after a second jab to 53% by the eight to tenth week and 19% by the 12th and 14th week.

While a third boost with BNT162b2 does increase Omicron-specific antibody levels (21-fold by week 3; 8-fold by week 4) as compared to four weeks post the second dose, questions of vaccine durability persist. As assessed between weeks 3 to 8 after the vaccine administration, a dramatic decline occurs in antibody protection representing a 4.9-fold decline for the original variant, 5.6 fold when addressing Delta, and another 5.4-fold drop.

Study Limitations

The authors report that this cross-sectional design precludes any individual analysis of decreased antibody levels, yet the authors point out “the observed decrease in population neutralizing antibody titers corresponds to the decrease in vaccine efficacy against polymerase chain reaction–confirmed Omicron infection in Denmark and symptomatic Omicron infection in the United Kingdom.”

Author’s Point of View

The study team led by corresponding author Ria Lassaunière, Ph.D., suggests that based on the study findings, the benefits of both the second and third Pfizer jabs are “transient,” suggesting a necessary fourth booster, especially in elderly populations. The authors note the potential that “conserved T-cell immunity” as well as “non-neutralizing antibodies” could be an additional positive factor with BNT162b2 preventing hospitalization and death.

Statens Serum Institut

This Danish apex research institute called Statens Serum Institut is part of the Danish Ministry of Health and was set up support investigations into combatting and preventing infectious disease, congenital disorders, and threats from weapons of mass destruction.

Founded originally in 1902 in some military barracks, the research center has expanded and now represents one of the largest research institutions in Denmark.

TrialSite Opinion

The consensus of medical establishments—including apex research institutes, public health agencies, and regulators, as well as specialists in academia mostly concur on the importance of a third dose of the mRNA-based vaccine, which at least, temporarily boosts protection from more severe disease and death due to the waning effectiveness after the second dose. Of course, now, in the United States, a fourth dose is recommended for the elderly and other at-risk cohorts, and the Danish authors don’t disagree with this approach.

TrialSite has chronicled Omicron’s spread associated with more breakthrough infections, hospitalizations, and deaths in places like Australia, New Zealand, and South Korea. This is probably due to the highly contagious nature of that variant. So, death rates are overall lower in Australia even though that nation experiences double the deaths in the first months of 2022 than in 2020 and 2021 combined.

Evidence of waning effectiveness associated with the third dose of BNT162b2—and even some data raising questions about the fourth dose—lead to a scientific gray zone moving forward. FDA officials such as Paul Marks have gone on the record that American society cannot continue to keep boosting the population while an annual shot like the flu shot may be an accepted reality in the future.

Experts such as David Wiseman attending FDA and CDC meetings suggests an attempt “to boost ourselves out of Omicron where quasi-vaccine efficacy is negative, is the immunological equivalent of heroin addiction, providing less and less benefit with greater opportunity for harm.”

While most vaccine effectiveness studies center on neutralizing antibodies, other parts of the human immune system are relevant, including the production of T cells to fight off invaders. While they are not as potent at immediately thwarting invading pathogens such as SARS-CoV-2 (e.g., Omicron and other mutations), they may be more durable and thus important. What’s the mRNA vaccination impact on this form of immune response?

According to the National Institutes of Health (NIH). Studies reveal that the COVID-19 vaccines do elicit T cells that recognize Omicron regardless of how many mutations in the spike protein. But what are the quantitative benefits of this protection?

And what about vaccine safety?

This media platform does take exception to blanket statements that the novel and innovative COVID-19 vaccines are overwhelmingly safe and effective. mRNA vaccines are associated with significant safety signals, and this media forecasts that ever more data (and corresponding analyses) will get circulated into the mainstream media, raising more concerns and debate—which is a good thing.

From a value or evidence-based approach, the economics of the first batch of COVID-19 vaccines should be carefully scrutinized. Pfizer has generated unprecedented revenues from BNT162b2 based in part, on a massive indirect subsidy of clinical trials by the U.S. government via pandemic response, orchestration, and coordination of NIAID trial site networks to streamline patient recruitment (the most expensive part of a study), government promotion of vaccination campaign as a way to eliminate the pathogen (enormous marketing subsidy), mandates at the national, state, and local government level) not to mention substantial direct government advanced purchases.  

Of course, on its face, much of this was justified, given we have faced an unprecedented deadly pandemic. Yet early on, front-line physician attempts to showcase treatments were cast aside while information wars were waged against generic/off-label alternative approaches for early care.

While Pfizer should undoubtedly earn some profit for the value provided, should those be windfall profits during a pandemic for a product that continuously wanes in effectiveness as measured by diminishing antibody protection? The move to value and evidence-based care necessitates payment on comprehensive performance.

Lead Research/Investigator

Ria Lassaunière, Ph.D., Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut; Corresponding Author

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