Medical Study Shows that Pfizer Shot was Only 42% Effective Against COVID Infection in July 2021

Posted on 08/11/2021

In a study titled, “Comparison of two highly-effective mRNA vaccines for COVID-19 during periods of Alpha and Delta variant prevalence”, that was posted on medRxiv, raises concerns about the mRNA vaccines’ effectiveness against Delta (Indian) variant, particularly Pfizer’s COVID shots. The study found the Pfizer vaccine was only 42% effective against infection in July 2021, when the Delta variant was dominant. The study has not been peer-reviewed.

The study found that the Moderna vaccine was 86% effective against infection over the study period, and Pfizer’s was 76%. Moderna’s vaccine was 92% effective against hospitalization and Pfizer’s was 85%. Moderna was 76% effective against COVID infection, and Pfizer was only 42% effective for the July time period.

STUDY ABSTRACT: Although clinical trials and real-world studies have affirmed the effectiveness and safety of the FDA-authorized COVID-19 vaccines, reports of breakthrough infections and persistent emergence of new variants highlight the need to vigilantly monitor the effectiveness of these vaccines. Here we compare the effectiveness of two full-length Spike protein-encoding mRNA vaccines from Moderna (mRNA-1273) and Pfizer/BioNTech (BNT162b2) in the Mayo Clinic Health System over time from January to July 2021, during which either the Alpha or Delta variant was highly prevalent. We defined cohorts of vaccinated and unvaccinated individuals from Minnesota (n = 25,589 each) matched on age, sex, race, history of prior SARS-CoV-2 PCR testing, and date of full vaccination. Both vaccines were highly effective during this study period against SARS-CoV-2 infection (mRNA-1273: 86%, 95%CI: 81-90.6%; BNT162b2: 76%, 95%CI: 69-81%) and COVID-19 associated hospitalization (mRNA-1273: 91.6%, 95% CI: 81-97%; BNT162b2: 85%, 95% CI: 73-93%). However, in July, the effectiveness against infection was considerably lower for mRNA-1273 (76%, 95% CI: 58-87%) with an even more pronounced reduction in effectiveness for BNT162b2 (42%, 95% CI: 13-62%). Notably, the Delta variant prevalence in Minnesota increased from 0.7% in May to over 70% in July whereas the Alpha variant prevalence decreased from 85% to 13% over the same time period. Comparing rates of infection between matched individuals fully vaccinated with mRNA-1273 versus BNT162b2 across Mayo Clinic Health System sites in multiple states (Minnesota, Wisconsin, Arizona, Florida, and Iowa), mRNA-1273 conferred a two-fold risk reduction against breakthrough infection compared to BNT162b2 (IRR = 0.50, 95% CI: 0.39-0.64). In Florida, which is currently experiencing its largest COVID-19 surge to date, the risk of infection in July after full vaccination with mRNA-1273 was about 60% lower than after full vaccination with BNT162b2 (IRR: 0.39, 95% CI: 0.24-0.62). Our observational study highlights that while both mRNA COVID-19 vaccines strongly protect against infection and severe disease, further evaluation of mechanisms underlying differences in their effectiveness such as dosing regimens and vaccine composition are warranted.


More Side Effects – European Medicines Agency to Report on Moderna Shots
Pfizer is the biggest supplier of COVID-19 vaccines to the European Union.

On another note, three new conditions reported by a small number of people after vaccination with COVID-19 shots from Pfizer and Moderna are being studied to assess if they may be possible side-effects, according to the European Medicines Agency (EMA). Erythema multiforme is a form of allergic skin reaction. Nephrotic syndrome is a renal disorder characterized by heavy urinary protein losses. Glomerulonephritis or kidney inflammation is also a condition. These are being studied by the EMA. In July 2021, EMA discovered a link between very rare heart inflammation (Myocarditis) and the mRNA vaccines.

Lambda Variant
The Lambda variant of the coronavirus continues to spread throughout South America. The United States government has let in nearly 1.1 million illegal migrants from the U.S.-Mexico border over the past year. Many of these migrants are from Latin America and other parts of the world. The humanitarian crisis at the U.S. border includes migrants that have overwhelmed local towns as a percentage of them have tested positive for COVID. In addition, a New University of Tokyo study finds the COVID Lambda variant could be vaccine resistant to the current vaccine lineup.

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