(CNN) People who got Covid-19 vaccines were not only less likely to die from the virus, but they were less likely to die from any cause over the following months, researchers reported Friday.
The research team was trying to demonstrate that the three authorized Covid-19 vaccines are safe and they say their findings clearly demonstrate that.
"Recipients of the Pfizer-BioNTech, Moderna, or Janssen vaccines had lower non--COVID-19 mortality risk than did the unvaccinated comparison groups," the researchers wrote in the weekly report of the US Centers for Disease Control and Prevention.
"COVID-19 vaccines authorized in the United States have shown again and again to be safe. This study also confirms their safety," Stanley Xu, a researcher at the Kaiser Permanente Southern California Department of Research and Evaluation, who led the study team, told CNN by email.
"In fact, it shows that people vaccinated for COVID-19 had lower death rates than those who were not vaccinated, even when COVID deaths were excluded. That's in addition to the mounting evidence from other studies showing that the COVID-19 vaccines are effective against COVID-19 infection, serious illness, and death."
The team studied 6.4 million people who had been vaccinated against Covid-19 and compared them to 4.6 million people who had received flu shots in recent years but who had not been vaccinated against coronavirus. They filtered out anyone who had died from Covid-19 or after a recent positive coronavirus test.
"During December 2020-July 2021, COVID-19 vaccine recipients had lower rates of non-COVID-19 mortality than did unvaccinated persons after adjusting for age, sex, race and ethnicity, and study site," they wrote.
People who got two doses of Pfizer vaccines were 34% as likely to die of non-coronavirus causes in the following months as unvaccinated people, the study found. People who got two doses of Moderna vaccine were 31% as likely to die as unvaccinated people, and those who got Johnson & Johnson's Janssen vaccine were 54% as likely to die, Xu said
Part of this is probably because people who get vaccinated tend to be healthier than people who don't the researchers noted.
"The lower mortality risk after COVID-19 vaccination suggests substantial healthy vaccinee effects (i.e., vaccinated persons tend to be healthier than unvaccinated persons), which will be explored in future analyses," they wrote.
"This finding reinforces the safety profile of currently approved COVID-19 vaccines in the United States. All persons aged 12 years and older should receive a COVID-19 vaccine," they concluded.