Mayo Clinic’s new preprint study showed that the Pfizer COVID-19 vaccine is notably less effective as compared to Moderna vaccine in terms of fighting the delta variant.

The study, however, is not yet peer-reviewed.

The authors emphasized that the two vaccine brands maintain their high effectiveness against serious diseases caused by the COVID-19’s delta variant.

But on average, vaccines produced by Modernahas showed 78 percent effectiveness against infection from the more contagious delta variant than Pfizer with only 42 percent.

“The elephant in the room is the amount of mRNA in the vaccines,” co founder and chief scientist at Nference, Venky Soundarajan, said.

Soundarajan noted that the Moderna vaccine contains more mRNA as compared to Pfizer. This can equal the deviation on the protection it can give against the delta variant.

The chief scientist, while saying that the greater mRNA characteristic by Moderna boosts its protection against the delta, emphasized that the two vaccine brands differ in nanoparticulation and nucleotide sequences used.

Soundarajan added that the Moderna vaccine is linked to a boost in mild side effects than Pfizer.

“Thinking back, we think that might be because of the dose,” he said. “There is more mRNA, which means it boosts a stronger immune response.”

The study looked at over 75, 00 people in the Minnesota-based Mayo Clinic system. A peer review is being conducted for the said findings, SFGate reported.

Soundarajan said that the study has some “caveats”. Genome sequencing, for example, is limited. This led the authors to approximate the number of suspected delta variant cases through deduced information. This means that those who were involved in the study were not required to test positive with the delta variant. But given that the delta variant is gaining dominance in the U.S., they were suspected to be infected.