From Fortune:
On Wednesday, Pfizer and partner BioNTech, makers of the United States’ first Food and Drug Administration (FDA) emergency authorized COVID vaccine, saw their share prices plummet as discouraging new research from the Mayo Clinic forced investors to question how long the Pfizer vaccine remains effective at preventing coronavirus infections and protecting those who are vaccinated from getting sick with a Delta variant case.
Pfizer’s shot may be significantly less effective than Moderna’s against breakthrough infections (42% efficacy for Pfizer/BioNTech versus 76% for Moderna), according to the data, and Pfizer stock ended the day down nearly 4% while Germany’s BioNTech slipped 13.76%. But the urgency of the investor reaction underscores the gravity of the Delta wave and uncertainty surrounding a pioneering vaccine that’s been on the U.S. market for exactly nine months.
One key issue raised by the study, which has yet to be published in a peer-reviewed medical journal, for the millions of Americans who received two doses of Pfizer’s treatment is whether or not a Pfizer booster dose—either of the currently available jab or a new and updated version—is necessary to keep up with mutations or prevent COVID-19 reinfection from older coronavirus strains. Given that Pfizer expects to have delivered 500 million doses of its COVID vaccine under supply agreements with the U.S. government by the spring of 2022, should Americans be worried about catching a nasty case of the Delta variant or spreading the pathogen to others if they’re immunized with Pfizer’s product?
In short: There is now mounting evidence that mRNA-based vaccines such as Pfizer’s and Moderna’s lose potency over time and especially against the Delta variant, and that the Pfizer vaccine’s efficacy drop is significantly more dramatic. The Mayo Clinic study noted a wide shortfall in the mRNA vaccines’ ability to prevent infections among patients using the Mayo Clinic Health System for the month of July, when Delta variant cases made up more than 70% of new local infections in its home state of Minnesota, compared with earlier in the year. Between January and July, Moderna’s jab was 86% effective at preventing infection in this population while Pfizer’s was 76% effective. But for July alone, those numbers fell to 76% for Moderna and 42% for Pfizer, and the researchers observed similar drops for the Pfizer shot outside of Minnesota in states with high COVID counts such as Florida. (On a brighter note, both the Moderna and Pfizer vaccines still proved highly effective at preventing the need for COVID infection-related hospitalization at 92% and 85% efficacy, respectively.)
The good news is, if vaccinated but infected, you probably won’t need a hospital or die. The bad news is you might not know you have it before symptoms set in, meaning you can still spread the virus hither and yon and could face the prospect of a few days if not weeks of sickness at home. Do the world a favor. Wear a mask.
New Orleans, a city that lives or dies by tourism, just began requiring a vaccination certificate or proof of a recent negative Coivid test for patrons of its bars, restaurants, music venues, etc. And tests right now are in short supply in hard-hit areas.
