New CDC study: mRNA vaccines 90% effective
In their clinical trials, the Pfizer and Moderna vaccines did okay, well enough for the FDA to grant emergency use authorization. But in a real-world study, where participants were all on the front lines fighting Covid, the vaccines proved 90% effective against the virus – not just the symptomatic disease. In the clinical studies, Pfizer and Moderna were testing against disease.
According to the CDC-sponsored study released today, it didn’t matter which vaccine the participants received. What mattered was that both vaccines were designed using messenger RNA to repel the coronavirus. The results showed that the vaccines were even effective against asymptomatic virus.
Messenger RNA, or mRNA, carries instructions into a cell to tell it how to function. In the case of the vaccines, the target for the message is the spike protein. This protein has three functions: it recognizes the virus, it permits the virus to attach to it, and then it allows entry into the cell. Once that happens, all viral hell breaks loose. But with the vaccines, the messenger is relaying instructions to produce antigens, those molecules that tell the immune system to recognize an invading force. This lets the body recognize and attack the spike protein on actual SARS-CoV-2 viruses if a person comes in contact with them.
And apparently, recognize it they do.
The CDC wanted to know how the mRNA vaccines worked in the real world, so they enrolled 3,950 people – health care workers, first responders, and others – from six states. The 13-week study ran from mid-December to mid-March.
The vaccines did well even with only one shot, even though both types typically require two shots for a full regimen. In the study, the risk of infection dropped by 80%, two weeks after the first dose of vaccine was given.
The participants submitted their own nasal swabs every week for testing. Close to 11% of the infections contracted were asymptomatic. Nearly 60% of the infections were discovered before the infected person developed symptoms. In total, 205 people had diagnosed infections. It is worth noting that 69% of those in the study did not have any chronic conditions. About 1,200 had more than one.
Breaking down where the infections occurred, the study said those infected were mostly male, Hispanic, first responders. The states with the most cases were Texas, Florida and Arizona.
“The study demonstrates that these two mRNA vaccines can reduce the risk of all SARS-CoV-2 infections, not just symptomatic infections,” a CDC press release said.