Covid-19 roundup: New study suggests Moderna vaccine may be more effective than Pfizer against the Delta variant; Pentagon to require vaccines for members of the military
A study of patients in the Mayo Clinic Health System across multiple states suggests those who received Pfizer’s Covid-19 vaccine are at a two-fold higher risk of breakthrough infection compared to those who got the Moderna vaccine.
It’s important to note that the study, published Sunday in the preprint server medRxiv, has not been peer-reviewed.
The study began in Minnesota, where researchers have been analyzing the efficacy of the vaccines on a monthly basis since February 2021. As cases increased in July and the Delta variant became more prominent, the scientists measured a 76% efficacy against infection for the Moderna vaccine, and a 42% efficacy against infection for Pfizer’s. Those rates are much lower than the figures seen through April 2021 (93.3% for Moderna and 86.1% for Pfizer).
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