According to a study by US health authorities published on Wednesday, past infection protects more than vaccination once morest the Delta variant.
Against the Delta variant, unvaccinated people who had previously contracted Covid-19 were better protected than people who were only vaccinated, according to a study by American health authorities published on Wednesday.
Despite everything, “vaccination remains the safest strategy” once morest the disease, underlined the Centers for Prevention and Control of Diseases (CDC) by publishing these data. Indeed, contracting the disease exposes you to serious complications, while vaccines have proven to be extremely safe and effective.
This study was also conducted before booster doses became widely available, and before the appearance of the Omicron variant, which now accounts for more than 99% of new cases in the United States. It is therefore possible that the cards are currently being reshuffled. However, these results provide key elements for better analyzing the differences between immunity acquired by vaccines or following an infection.
Health authorities studied the cases in the states of New York and California from the end of May to November 2021. Delta became the majority in the United States at the end of June. Throughout the period analysed, the least well-protected people were by far those who had neither been vaccinated nor had fallen ill in the past. But before Delta, people who had been vaccinated and had never contracted Covid-19 were better protected than people who had not been vaccinated but had already fallen ill. After Delta arrived, the relationship reversed.
The study analyzed, for the beginning of October, the risk of catching Delta compared to that incurred by those most likely to contract it, namely people who have not been vaccinated or infected in the past. Vaccinated individuals (but never infected) thus had six times less risk than they of catching it in California, and regarding five times less in New York. But this risk was even further reduced for people previously infected (but not vaccinated): by 29 in California, and by 15 in New York.