Should you worry about breakthrough infections if you’re vaccinated? Not really, says Dr. Ashish Jha

“Among UNvaccinated, about 1 in 20 infections lead to hospitalization and 1 in 200 lead to death. Vaccines cut risk of each by 90%.”

Dr. Ashish Jha. Elise Amendola / AP

If you’re vaccinated and are wondering how concerned you should be about getting sick with a breakthrough case of COVID-19, Dr. Ashish Jha says you don’t really need to worry.

The dean of the Brown University School of Public Health laid out his reasoning in a thread on Twitter Tuesday night. While the daily risk of breakthrough infection among vaccinated individuals in the United States is about 1 in 5,000, Jha said those estimated 36,000 daily breakthrough infections may sound “bad,” but should not be that worrying if you’re vaccinated.

“What does 36K infections mean in terms of hospitalizations, deaths?” he wrote. “Among UNvaccinated, about 1 in 20 infections lead to hospitalization and 1 in 200 lead to death. Vaccines cut risk of each by 90%. Which means daily, 180 vaccinated folks getting hospitalized and about 18 dying.”


The doctor said if he examines the case fatality rate, or CFR, which represents the percentage of all recorded infections resulting in death, the number is about 0.12% for vaccinated individuals, or 40 deaths a day.

“So how bad is 18 (or even 40) deaths a day?” Jha wrote. “After accounting for proportion of population vaccinated, it’s lower than daily deaths in an [average] flu season.” 

Daily deaths in a typical flu season are about 100, and he stressed that COVID-19 breakthrough deaths can likely be driven even lower by getting booster shots to vulnerable individuals, such as the elderly or the immunocompromised who are experiencing most of the deaths from breakthrough infections.

When it comes to “Long COVID,” Jha said so far evidence suggests the condition is “far less likely” among vaccinated individuals who have experienced a breakthrough case, compared to those who were unvaccinated and contracted the virus. 

“Bottom line? COVID deniers spent much of last year saying COVID is no worse than the flu,” he wrote. “That was nonsense and we all knew it. Now … these terrific vaccines have turned risk of bad outcomes from COVID into something milder than the typical flu. And that is a good thing.”

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