A retrospective study involving more than 1.2 million people has shown that COVID19 infections in “fully” vaccinated people are rare, but are three times more common and severe in people with weaker immune systems.
The results of this study have been published in the “Journal of Medical Economics” and have been directed by researchers from Pfizer, who have co-developed with BioNTech, one of the COVID19 vaccines available today.
Only 0.08% of those vaccinated experienced an outbreak of infection
Analyzing health care records, the team in charge of this study found that, within their group of fully vaccinated people, only 0.08% experienced an outbreak of infection between December 10, 2020 and July 8, 2021. However, while immunosuppressed people accounted for only 18 percent of the people studied, they accounted for more than 38% of infections, nearly 60 percent of all hospitalizations, and 100% of deaths.
The proportion of people with advanced infections was three times higher among immunocompromised individuals (0.18%) than among the control group of non-immunocompromised individuals (0.06%).
Manuela Di Fusco, lead author of the Pfizer Health Economics and Outcomes Research team, has expressed that “the results complement other real-world studies and support the introduction of a third dose of the vaccine against COVID19 to increase protection among immunocompromised individuals. ”.
More than 1.2 million people vaccinated against COVID19 older than 16 years were studied
“Several countries are currently experiencing a resurgence of SARS-CoV-2 infections despite the rollout of mass vaccination programs… While COVID19 mRNA vaccines help protect people from infection and serious disease, the risk of progression in fully vaccinated people is not completely eliminated ”, the study author has also determined.
For this study, the Pfizer team did a large collection of managed data from American healthcare. Specifically, it analyzed the health records of 1,277,747 people over the age of 16 who had received two doses of the COVID19 BNT162b2 mRNA vaccine between December 10, 2020 and July 8, 2021.
On the other hand, on October 11, the World Health Organization (WHO) recommended that people with weakened immune systems receive an additional dose of the COVID19 vaccine, due to their increased risk of contracting infections after vaccination. standard.