A new preprint study(LINK) that raises concerns about the mRNA vaccines’ effectiveness against Delta — particularly Pfizer’s COVID vaccine, Axios reported.
The study found the Pfizer vaccine was only 42% effective against infection in July, when the Delta variant was dominant. This runs contrary to endless media reports that most new COVID cases are from the unvaccinated.
Axios summarized:
The study, conducted by nference and the Mayo Clinic, compared the effectiveness of the Pfizer and Moderna vaccines in the Mayo Clinic Health System over time from January to July.
- Overall, it 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%.
- But the vaccines’ effectiveness against infection dropped sharply in July, when the Delta variant’s prevalence in Minnesota had risen to over 70%.
- Moderna was 76% effective against infection, and Pfizer was only 42% effective.
- The study found similar results in other states. For example, in Florida, the risk of infection in July for people fully vaccinated with Moderna was about 60% lower than for people fully vaccinated with Pfizer.
Although it has yet to be peer-reviewed, the study raises serious questions about both vaccines’ long-term effectiveness, particularly Pfizer’s- Axios reported.