COVID-19: Natural immunity was more effective than vaccines for the delta variant

While much of the world has relied on vaccines for protection against COVID-19 infection, a new US study has found that a prior infection with the virus provided as much protection from a repeat infection as the vaccines did. The rise of the Delta variant.

Analyzing data from New York and California, the US Centers for Disease Control and Prevention found that before Delta’s arrival last summer, people who had taken the vaccine and had not previously contracted the virus were half as likely to develop COVID. Was. People who had the disease before were not vaccinated. However, the researchers also noted that the results do not apply to the Omicron version of the virus. The study is published in the Centers for Disease Control and Prevention’s (CDC) Morbidity and Mortality Weekly Report.

People who have not been vaccinated and do not have a history of prior infection are at maximum risk, the research said, adding that vaccination is still the key to prevention. The study also didn’t take into account the rollout of boosters that have been shown to restore protection against the immune-escaping Omicron variant. The study analyzed non-vaccinated and vaccinated individuals from May to November 2021, before and after the summer boom of the Delta variant. By fall, people who had previously been exposed to infection, regardless of whether or not they had shots, were less likely to be diagnosed with COVID19 than those who were vaccinated but had no previous history of infection.