Vaccination against COVID-19 protects against reinfection by 60-94%. A study on this topic by scientists at the Danish State Serum Institute (Statens serum institut - SSI) was published in PLOS Medicine.
The Danish experts took national results from January 2020 to January 2022 on infections and vaccinations from nationwide registries. They contained more than 200,000 people who tested positive for coronavirus.
Researchers looked at the outcome of vaccination with mRNA-1273 and BNT162b2 vaccines. The study found that those who recovered from the infection reduced the chance of reinfection by 71 percent during the Alpha strain outbreak, by 94 percent during the Delta strain outbreak and by 60 percent during Omicron activity.
The findings of the new study are consistent with a study in Qatar, which showed that two doses of mRNA vaccine from COVID-19 reduced the risk of reinfection by 55.1%.
The authors noted that their study was too short to determine whether the vaccine protects against severe consequences such as death and hospitalization. Nevertheless, their data proved the effectiveness of the SARS-CoV-2 re-infection vaccine, highlighting the need for vaccination even for those who may be protected by natural immunity.