In April 2020, people around the globe were struggling with unprecedented societal shutdowns aimed at slowing Covid-19. Six years later, school closures, mask wearing, and social distancing are dim memories. Covid still animates political debate — but it increasingly feels like a threat from another era. So what happened?
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Virtually Everyone Has Some Immunity Now
When Covid first spread, none of us had any immunity to this novel virus — which allowed it to cause catastrophic harm. In the years since, the immune systems of nearly every human on the planet have developed defenses against SARS-CoV-2, either through prior infection, vaccination, or both. The exception is infants in their first year or two of life.
Many experts told STAT this shift in population-level immunity explains why the threat has so markedly subsided. But not everyone agrees on the mechanism. Lia van der Hoek, a Dutch virologist who discovered the NL-63 coronavirus and has tracked reinfection patterns with common-cold coronaviruses for years, believes the turning point was actually the emergence of the Omicron variant in late 2021.
“Though more adept at evading immunity, Omicron viruses caused much milder disease. The current circulating viruses are all descendants of Omicron.”
— Lia van der Hoek, Director, Virus Discovery Group, Amsterdam University Medical Center
Van der Hoek had warned as early as fall 2020 — in a paper tracking reinfection rates with common-cold coronaviruses among a cohort of Amsterdam men — that we shouldn’t expect full long-lasting immunity after Covid infection. Reinfection with other human coronaviruses can happen within a year. She doesn’t believe immunity alone explains the changed pattern. In her view, Omicron’s comparative mildness is the real story. The two theories are not mutually exclusive.
The Numbers Tell a Clear Story
In 2021, Covid was the third most common cause of death in Americans 18 and older, according to the CDC. By 2023 it had fallen to 10th. In 2024, it ranked 15th — below influenza (11th). For children and teenagers, Covid fell out of the top 10 causes of death in 2023.
CDC scientists estimate that between October 2024 and September 2025, between 45,000 and 64,000 Americans died from Covid. That compares to roughly 100,000 estimated Covid deaths in each of the two preceding seasons. “Every single year since the pandemic, the overall severity and impact of Covid has been going down,” said Fiona Havers, a former CDC medical epidemiologist now at Emory University.
Death certificates often list a broad cause like “pneumonia” or “respiratory failure” — not Covid specifically. CDC scientists use mathematical modeling to estimate how many deaths are attributable to Covid. The same method has long been used to estimate flu deaths. These figures are estimates, not exact counts.
What the Sewers Are Saying
WastewaterSCAN — a surveillance project led by researchers at Stanford and Emory universities that monitors municipal sewage for pathogens — is currently detecting SARS-CoV-2 at its lowest levels ever recorded in the program’s history.
“The levels that we’re seeing in wastewater are the lowest that we’ve ever seen,” said Alexandria Boehm, the project’s principal investigator and a professor of civil and environmental engineering at Stanford. She cautions that lower detections could reflect either fewer infections or reduced shedding per infected person — or both. Boehm also notes that previous years have seen a summer surge beginning to appear in wastewater data around May and June. Whether that recurs in 2026 remains to be seen.
Note: Bars represent approximate relative signal, not absolute concentration values. Exact figures vary by region.
Nuisance or Peril? What Experts Think Now
Most experts consulted by STAT believe SARS-CoV-2 has effectively become — or is rapidly becoming — one of the many respiratory viruses that circulate regularly, causing illness ranging from mild sniffles to a knock-you-off-your-feet week in bed. But important caveats remain.
Malik Peiris, professor emeritus of microbiology at the University of Hong Kong and co-discoverer of two earlier coronaviruses, now views SARS-CoV-2 as “another seasonal respiratory virus.” He believes a variant causing major public health impact is unlikely — though not impossible.
Ben Cowling, chair of epidemiology at Hong Kong University’s School of Public Health, isn’t convinced Covid is yet as minor a threat as other circulating coronaviruses. “It’s reasonable to think it’s on that trajectory,” he said — but he’s “not sure if we’re there yet.”
Lia van der Hoek is more definitive: “It’s just number 5 of the common cold coronaviruses.” The four seasonal coronaviruses already circulate regularly, causing colds. She believes SARS-CoV-2 has joined their ranks — and if not quite as mild, “it will be there soon.”
Virologist Vineet Menachery of the Emory Vaccine Center notes: “New strains are relatively more capable of overcoming immune responses, but infection outcomes are more mild” — aligning with the pattern seen in the original common-cold coronaviruses.
“One has to understand that Covid-19 is a mucosal infection that can invade in people who have poor immune responses. That means most healthy people can control the infection, but the very young and the very old may not.”
— Stanley Plotkin, Vaccinologist, developer of the rubella vaccineWho Is Still at Serious Risk
While severe Covid disease has declined across the population, the risk has concentrated — not disappeared. The pattern now mirrors other respiratory viruses: people at the extremes of age and those with compromised immune systems face the greatest danger.
Long Covid — the syndrome of persistent symptoms following infection — is still being reported, though its incidence has declined substantially since the early pandemic years. This decline is attributed in part to the protective effect of Covid vaccination. Myocarditis (heart muscle inflammation, most commonly reported in teenage boys following vaccination) and multisystem inflammatory syndrome in children (MIS-C) have also become significantly less frequent.
A Shifting Vaccine Landscape
The policy picture around Covid boosters has shifted considerably. The CDC’s Advisory Committee on Immunization Practices (ACIP) was in the process of narrowing its universal booster recommendation — from everyone 6 months and older to a targeted approach focusing on high-risk groups — when it was disbanded by HHS Secretary Robert F. Kennedy Jr. in 2025. A newly appointed ACIP voted last September to recommend that everyone 6 months and older may receive a Covid shot if they wish, after discussing it with their physician. Several peer countries had already adopted a similar risk-targeted approach.
Meanwhile, Pfizer halted an FDA-requested clinical trial in healthy adults aged 50 to 64, citing insufficient volunteer recruitment. And a CDC study reportedly showing that 2024–2025 winter vaccines reduced emergency care and hospitalization risk by 50% was shelved by HHS before publication, according to The Washington Post.
What This Means for You
For most healthy adults and children, Covid has effectively become one of many respiratory viruses — capable of ruining a week, but no longer the civilization-shaking threat of 2020 and 2021. For older adults, infants, and immunocompromised individuals, meaningful risk remains, and annual vaccination still offers documented protection against hospitalization. No one knows yet whether a summer 2026 wave will emerge — wastewater surveillance will offer an early signal. The science suggests we are watching a virus find its endemic equilibrium. Whether it has fully settled there, experts are still watching.
