Study: Single Vaccine Dose Highly Effective for COVID-19 Survivors

The study was conducted by scientists from the Icahn School of Medicine at Mount Sinai, in New York, and is based on blood samples from 110 people, 67 of whom had not been infected with the virus and 43 had been. The results showed that after the first dose, participants who had already had Covid-19 "quickly developed uniform and high antibody titers in the days following the injection". In addition, antibody levels were 10 to 45 times higher than in those who had not previously been infected, according to the scientists, who took samples at regular intervals.

At the second dose, antibody levels in those who had already had the disease were still six times higher on average than in those who had never been infected. However, according to the researchers, "no increase in antibody titers was observed in former Covid-19 patients who received the second dose."

This study published in the New England Journal of Medicine also revealed that people who had already developed natural immunity after their infection with the virus often have mild side effects after their vaccination (fever, fatigue, chills, headaches or muscle or joint pain). But this theory needs more in-depth studies to confirm or not this trend.