COVID-19: Natural Immunity Was More Effective Than Vaccines For Delta Variant

While most of the world has been relying on vaccines for protection against the COVID-19 infection, a new US study has brought to fore that a prior infection from the virus provided as much protection from a repeat bout of infection as vaccines did, during the delta variant’s rise.

From an analysis of data from New York and California, the US Centers for Disease Control and Prevention found that before delta arose last summer, people who had taken the vaccine and had not contracted the virus earlier were half as likely to be diagnosed with COVID as unvaccinated people who had the disease earlier. However, the researchers have also stated that the results do not apply to the Omicron variant of the virus. The study has been published in Centres for Disease Control and Prevention (CDC)’s Morbidity and Mortality Weekly Report.

People who are both unvaccinated and don’t have a history of prior infection are at maximum risk, said the research, adding that vaccination still remains the key to prevention. The study also doesn’t take into account the rollout of boosters that have been shown to restore protection against the immune-evading omicron variant. The study analyzed unvaccinated and vaccinated individuals from May to November 2021, before and after the summer surge of the delta variant. By fall, those who had contacted the infection earlier, irrespective of having shots or not, were less likely to be diagnosed with COVID19 than those with vaccination but no previous history of infection.