A new pre-print Israeli study has found that people with natural immunity to COVID-19 could be 13 times less likely to contract the respiratory virus than those who were solely vaccinated against the disease.

Conducted by researchers at Maccabi Healthcare and Tel Aviv University, the yet-to-be peer-reviewed study found that when comparing individuals previously infected with the virus and those that received two jabs of the Pfizer-BioNTech shot, those with natural infection saw greater protection against the delta variant and breakthrough infection.

“SARS-CoV-2-naïve vaccinees had a 13.06-fold increased risk for breakthrough infection with the Delta variant compared to those previously infected, when the first event (infection or vaccination) occurred during January and February of 2021,” the study read. “The increased risk was significant for symptomatic disease as well. When allowing the infection to occur at any time before vaccination (from March 2020 to February 2021), evidence of waning natural immunity was demonstrated, though SARS-CoV-2 naïve vaccinees had a 5.96-fold increased risk for breakthrough infection and a 7.13-fold increased risk for symptomatic disease.”

The analysis also found that solely vaccinated individuals “were also at a greater risk for COVID-19-related-hospitalizations compared to those that were previously infected.”

The study ultimately concluded that “natural immunity confers longer lasting and stronger protection against infection, symptomatic disease and hospitalization caused by the Delta variant of SARS-CoV-2, compared to the BNT162b2 two-dose vaccine-induced immunity” and that “individuals who were both previously infected with SARS-CoV-2 and given a single dose of the vaccine gained additional protection against the Delta variant.”

https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1