Data showing lower death rate for coronavirus delta variant doesn’t mean it’s less dangerous

The delta variant of the coronavirus that causes COVID-19 has been found to be far more infectious than the original coronavirus.

An Instagram post claimed it’s far less lethal.

"Fear in perpetuity," the post said. "Delta variant is approximately 19 times less deadly than the already massively inflated death numbers we got for China virus part 1. Mainstream media about to tell you otherwise 24/7."

The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)

Experts say there’s not enough data yet to determine whether the delta variant is less dangerous than earlier variants. 

Even as COVID-19 cases are on the decline and Americans resume much of normal life, new mutations of the virus are raising concern, particularly the delta. That variant, first identified in India in December, swept through Britain, and the first U.S. case was identified in March, according to the Yale School of Medicine. 

The U.S. Centers for Disease Control and Prevention predicts the delta variant will soon account for 45% of infections in a large group of states that span from Missouri to Montana.

The Instagram post includes a portion of Table 2 from a June 25 technical report on coronavirus variants by Public Health England, a government agency. The table indicates the case fatality rate is 0.1% for delta, compared with 1.9% for the original alpha variant — or 1/19th the rate. That’s how the post arrives at the conclusion that delta is "19 times less deadly."

Public Health England spokesperson James McCreadie told PolitiFact the post "is factually incorrect and manipulates our data."

McCreadie told us on July 5 that as of June 21, 117 people in England had died with the delta variant, including 44 who were unvaccinated. "Many factors contribute to death, including age, comorbidities and deprivation. It is too early to assess the case fatality ratio compared to other variants," he said.

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Experts pointed out that lower case fatality rates would be expected, simply because so many people have been vaccinated in recent months, whereas the original coronavirus had time to spread and cause severe disease long before vaccines became widely available. 

The vaccines authorized in the U.S. and the U.K. have been shown to substantially reduce the likelihood of getting infected with COVID-19, and to reduce the severity of the disease in those who do get infected.

Boston University professor Brooke Nichols, a health economist and infectious-disease mathematical modeler, noted that Table 4 of the same report shows that most people aged 50 and over who have been confirmed to be infected with the delta variant have had one or two doses of the vaccine. 

"The reported case fatality rate from Table 2 in the report is really just illustrative of the effectiveness of the vaccine in preventing severe disease," she said.

Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, said: "All variants are going to have a lower case fatality rate, because a significant portion of the population, especially those at high risk for death, are fully or partially vaccinated."

The delta virus was "tamer because of the high proportion of high-risk people that were protected by a combination of vaccination and prior immunity," he added. "Also, treatments have improved."

An Instagram post claimed that the delta variant of the coronavirus "is approximately 19 times less deadly."

A government report from England indicates that the fatality rate for the delta variant there is 0.1%, compared with 1.9% for the original coronavirus. The difference is a factor of 19.

But the agency cautions that it is too soon to make comparisons of the risk of death posed by variants and says the post misinterprets the data. 

We rate the post Mostly False.

CORRECTION: This article was corrected on Sept. 16, 2021, to remove an erroneous paragraph. The paragraph referred to a study in the journal Science; that study was not done on the delta variant but on the alpha variant.