Moderna vaccine offers double the protection against breakthrough Covid-19 infection

According to the study from the Mayo Clinic, rates of infection between "matched individuals" across its health system in Minnesota, Wisconsin, Arizona, Florida, and Iowa, showed the Moderna jab "conferred a two-fold risk reduction against breakthrough infection compared to [Pfizer]".

In Minnesota alone, between January and July, the Moderna shot had shown 86% efficacy, against 76% for its mRNA rival.

However, for July alone, the Moderna shot was 76% effective against infection, versus 42% in the case of Pfizer's vaccine.

The Mayo Clinic noted that the prevalence of the Delta variant in Minnesota had jumped from 0.7% in May to more than 70% in July.

Meanwhile, in Florida, which was in the midst of its largest Covid-19 surge to date, the risk of breakthrough infections in July was found to be 60% less among those inoculated with Moderna instead of Pfizer.

Not coincidentally, the day before Pfizer had told Axios that it and partner BioNTech could manufacture a tailor-made vaccine against the Delta variant in roughly 100 days.

Also according to Axios, data published earlier in the week on vaccine efficacy had acted as a "wake-up call" for the Biden administration.

The abstract of the May clinic study concluded saying: "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."

The US Food and Drug Administration was expected to announce if it had approved booster shots for immunocompromised people later on Thursday or Friday, the Wall Street Journal reported.