Julie Steenhuysen, Manas Misra

(Reuters). People infected by COVID-19 before were protected better against the Delta variant of the virus than were those who got vaccinated only. That suggests natural immunity may be more effective than vaccines, Californian and New York state health officials said on Wednesday.

The study showed that Delta protection was greatest in those who have been vaccinated after a COVID-related infection and the lowest for those who are not vaccinated or who have never been infected.

However, vaccines remain the most effective strategy to combat COVID-19 according to the U.S. Centers for Disease Control and Prevention Morbidity and Death Weekly Report.

These results are not applicable to Omicron, the variant of COVID-19 that now makes up 99.5% in the United States.

According to Dr. Ben Silk, a CDC researcher and one of the authors of the report, “The evidence from this report doesn’t change our vaccination recommendations.” He spoke at a press conference.

He said, “We know vaccination is the most effective way to safeguard yourself from COVID-19.”

Health officials from New York and California collected data between May and November to study the Delta variant’s dominance.

The study showed that those who had survived an infection previously were more likely to develop COVID-19 symptoms than those who received a single vaccine.

Silk explained that this was a significant change in the Alpha period.

He said that COVID-19 vaccine was better than any other method of protecting against subsequent infections.

However, in the fall and summer of 2021 when Delta was the dominant circulating form of the virus in America, he stated that “surviving an earlier infection now provided greater protection than vaccination”

Natural infection can lead to immunity, but there are significant dangers. Study found that approximately 135,781 New Yorkers and Californians had already died of COVID-19 by the end of 2021.

It did not contain information regarding the severity of an initial infection or the entire range of symptoms that could have been caused by previous infection.

A major drawback to this study was the fact that it was completed before widespread vaccination.

Erica Pan (state epidemiologist at the California Department of Public Health), stated in an email, “clearly showing” that vaccinations offer the best protection against COVID-19. They also provide additional protection for people with previous infections.

“Outside of this study, recent data on the highly contagious Omicron variant shows that getting a booster provides significant additional protection against infection, hospitalization and death,” Pan said.

Silk stated that the CDC was currently studying the effects of boosters, vaccinations, and previous infection in the Omicron surge. They expect to release additional reports once the data is available.