Since the early days of the pandemic, health officials have assessed the threat of COVID-19 by comparing it to the flu.
Initial, it wasn't even close. People hospitalized with the then-new respiratory disease in 2020 were five times more likely to die from their illness than patients hospitalized with flu during previous flu seasons.
Immunity from vaccines and previous coronavirus infections have helped contain COVID-19, to the point where researchers comparing the death rates of hospitalized COVID-19 patients and seasonal flu patients during the height of the 2022-2023 flu season found that the pandemic disease alone 61% more chance of death.
Now the same researchers have analyzed data for the fall and winter of 2023 and 2024. Dr. Ziyad Al-Alydirector of the Clinical Epidemiology Center at the VA St. Louis Health Care System, and his colleagues expected to find that the two respiratory diseases had finally become equal.
“There is a narrative that the pandemic is over, that it is a nothingburger” said Al-Aly. “We came here with the idea that we would do this retake and notice that from now on it would look like the flu.”
The VA team examined the electronic health records of patients treated at Veterans Affairs hospitals in all 50 states between October 1 and March 27. They focused on patients admitted because they had fever, shortness of breath or other symptoms due to COVID-19. 19 or flu. (People who were admitted for another reason, for example a heart attack, and subsequently turned out to have been infected with the coronavirus were not included in the analysis.)
The COVID-19 patients were, on average, slightly older than the flu patients (73.9 vs. 70.2 years old) and were less likely to be current or former smokers. They were also more likely to have received at least three doses of the COVID-19 vaccine and less likely to have avoided vaccinations altogether.
But after Al-Aly and his colleagues took these differences and a host of other factors into account, they found that 5.7% of COVID-19 patients died from their illness, compared to 4.2% of flu patients.
In other words, the risk of death from COVID-19 was still 35% greater than with the flu. The findings were published Wednesday in the Journal of the American Medical Assn.
“There is an undeniable impression that is there [COVID-19] is no longer a major threat to human health,” Al-Aly said. “I think it's largely driven by opinions and an emotional itch to move beyond the pandemic, to put it all behind us. We want to believe it looks like the flu, and we did – until we saw the data.”
Dr. Peter Chin-Hongan infectious disease specialist at UC San Francisco, said the study results match exactly what he sees at his hospital.
“COVID continues to make some people in our community very sick and dying – even into 2024,” he said. “While most won't get seriously ill from COVID, for some people it's just like 2020 again.”
This is especially true for people who are older and who have not yet received their gift most recently recommended COVID-19 boosterand who have not yet fully benefited from antiviral drugs such as Paxlovid. Chin-Hong noted that only 5% of COVID-19 patients in the study had been treated with antiviral drugs before being hospitalized.
Even if the death rates for COVID-19 and flu patients had been the same, COVID-19 would still be the biggest health threat because it sends more people to the hospital, Al-Aly said.
Between October 1 and the end of March, 75.5 in 100,000 Americans were hospitalized with the flu. according to the Centers for Disease Control and Prevention. During that same period, the hospitalization rate for COVID-19 was 122.9 per 100,000 Americans, says the CDC.
“COVID still carries a higher risk of hospitalization,” Al-Aly said. “And among those hospitalized, more will die as a result.”
Still, Al-Aly noted that moment in frustration 48% of adults in the US only received a flu shot this year 21% of adults are up to date on their COVID-19 vaccinations, according to the CDC.
Chin-Hong added that more than 95% of adults were hospitalized with COVID-19 last fall and winter had not received the last booster shotAccording to the CDC.
Considering all the tools available to prevent hospitalizations and deaths – and especially the fact that they are readily available to patients in the VA system – the 35% relative risk of death from COVID-19 compared to the flu was “surprisingly high,” said Chin- said Hong.
And it's not like the flu is a trivial health threat, especially for seniors and people with weakened immune systems. It routine kills tens of thousands of Americans every year, CDC data shows.
“Influenza is a consequential infection,” Al-Aly said. “Even if COVID becomes like the flu, it is still sobering and important.”
The researchers also compared death rates of VA COVID-19 patients before and after December 24, when the Omicron subvariant, known as JN.1, became the dominant strain in the United States. The difference was not statistically significant.
Just in the past two weeks, JN.1 appears to have been overtaken Through one of his descendants, a subvariant known as KP.2. It is part of a family of subvariants nicknamed 'FLiRT', a name that refers to some of the mutations that have emerged in the viruses' spike proteins.
So far, there is no evidence that KP.2 is more dangerous than JN.1, Al-Aly said.
“Are the hospitals full? No,” he said. “Are emergency rooms across the country overrun with respiratory diseases? No.” There are also no concerning changes in the amount of coronavirus detected in wastewater.
“If you look at all these data streams, we don't see any ominous signs that KP.2 is something that the general public should be concerned about,” Al-Aly said.
It's also too early to say whether FP.2 – or whatever comes next – will finally close the mortality gap between COVID-19 and the flu, he added.
“Maybe that will be the case when we do a rematch in 2025,” he said.
