The Star Tribune Pulitzer Prize-winning reporter Jeremy Olson writes that Mayo Clinic researchers have recently discovered “pronounced reduction” in the effectiveness of the Pfizer COVID-19 vaccine at preventing coronavirus infections, but still a high level of protection against severe illnesses and hospitalizations.

“Mayo Clinic researchers reported 76% effectiveness in the Pfizer vaccine protecting them from infection this year, but only 42% effectiveness in July amid the emergence of a more transmissible delta variant. The comparable effectiveness of the Moderna vaccine declined from 86% to 76%.”

Jeremy Olson in Star Tribune

According the study co-authors, their study further supports the effectiveness of both vaccines … despite the evolution of more transmissible Delta and other variants of the virus.

According to study authors, breakthrough Covid infections are inevitable and the Covid vaccines outperform others. The authors reportedly said ‘more research is needed in other parts of the world to verify the findings in Minnesota’.

• Mayo reports declining COVID-19 vaccine effectiveness
• Comparison of two highly-effective mRNA vaccines for COVID-19 during periods of Alpha and Delta variant prevalence
• Six months of COVID vaccines: what 1.7 billion doses have taught scientists
• Interim statement on COVID-19 vaccine booster doses | WHO

State infectious disease director Kris Ehresmann said that the Mayo findings are important but that more vaccinations are needed “because really the breakthrough infections that we’re seeing are the collateral damage to vaccinated persons from what’s happening predominantly in our unvaccinated community.”

“While it’s important to know how variants change the landscape and how they are more transmissible and all of those things,” Ehresmann added, “I think the important message is that we need to get a greater proportion of our population vaccinated in order to be in a better place to control and address variants, or we will see more and worse things coming down the road.”