Immunity From Prior Infection Gave Better Protection Than Vaccination During Delta Wave, CDC Says

A previous infection from Covid-19 provided better protection than vaccination against the virus during the Delta wave, the Centers for Disease Control and Prevention said Wednesday, citing data showing those who received immunity through prior infection or vaccination fared way better compared to those who were unvaccinated.

The data came from 1.1 million people and included testing, actual cases and immunization. It was collected in New York and California, the federal health authority said, spanning the months of May through November of 2021, the period in which the Delta variant became the dominant strain of Covid-19 in the U.S., before the Omicron variant started circulating in December last year.

“Before the Delta variant, Covid-19 vaccination resulted in better protection against a subsequent infection than surviving a previous infection,” CDC epidemiologist Benjamin Silk said. “When looking at the summer and fall of 2021, when Delta became predominant in this country, however, surviving a previous infection now provided greater protection.” According to the CDC, data from hospitalizations came from more than 50,000 people just in California.

The timeframe of the research coincided with when vaccinated people were experiencing waning immunity from vaccine-induced inoculation before the wider rollout of booster shots, Dr. Silk said.

Many have contended that the U.S., like many parts of Europe, should count immunity gained through prior Covid-19 infection as providing enough protection to work, enter restaurants and participate in other activities that some jurisdictions only allow for the vaccinated.