If you think a lot of people are suddenly sick with COVID, you’re not alone. Once again, the disease is on many people’s minds as infections, emergency room visits, hospitalizations, and even deaths are on the rise, according to the latest data from the U.S. Centers for Disease Control and Prevention (CDC).
The COVID-19 pandemic has not completely ended, but our baseline has changed. High numbers of infections, injuries, and deaths have been hitting us relentlessly since 2020, but despite some relative lulls, the risks associated with COVID-19 have not completely disappeared. After another winter wave in 2023–24, most COVID-19 indicators fell in the spring. Now, that trend appears to be reversing, driven by new variants and waning immunity from vaccines and infections.
It’s too early to tell whether this upward trend is a new wave. But given that the last four summers have seen a sharp increase in cases, it’s reasonable to expect that history will repeat itself this year, especially as temperatures drop in the fall.
And it will come as no surprise that our strategies for combating COVID haven’t changed much: wearing a mask in crowds, avoiding others if you have symptoms, getting tested after exposure to infected people (especially if you have symptoms), and staying vaccinated are all effective measures to reduce the spread of this persistent disease.
But it’s also true that the pandemic has changed a lot since 2020. SARS-CoV-2, the virus that causes COVID, mutates naturally, like all viruses. Every time it infiltrates a cell, it hijacks its DNA to create viral copies of itself and explodes to repeat the cycle. Random things happen regularly in these genetic copies: sometimes they do nothing or even weaken the virus. Other times, these mutations give the virus an advantage, allowing it to more easily evade immunity, infect more efficiently, spread more effectively, and leave more damage in its wake.
“A summer surge of COVID appears to be underway,” Dr. Rajendram Rajnarayanan of the New York Institute of Technology campus in Jonesboro, Arkansas, told Salon. “Based on the data right now: Cases are increasing in several states, with emergency room visits up 15% and hospitalizations up 25% compared to late May — a trend consistent with previous summer surges, which have historically occurred due to increased travel and indoor gatherings.”
“A summer wave of COVID appears to be underway.”
SARS-CoV-2 is not and has never been benign. It attacks the vascular system, affecting virtually every organ, including the kidneys, lungs, heart, and brain. Using its specialized spike protein as a master key, it can unlock and open the door to any cell with an ACE2 receptor, which happens to be many cells in the body. This is why it is so efficient at replicating inside us, but also why the virus is associated with lung scarring, digestive upset, blood clots, chronic fatigue, and literal brain damage manifesting as headaches, dizziness, anxiety, Parkinson’s-like symptoms, and other neurological disorders. The “zombie” fragments of COVID can persist in the body, causing these problems indefinitely.
A study published in May in the journal Nature Medicine that examined the medical records of more than 135,000 people infected with SARS-CoV-2 found that symptoms can persist for years. This plethora of symptoms is often referred to as long COVID or (post-acute sequelae of coronavirus disease PASC).
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The current swarm of SARS-CoV-2 variants comes primarily from a severely mutated strain dubbed Pirola (BA.2.86) that was first detected late last summer. Experts predicted it could cause serious problems, but its descendants like JN.1 became the dominant strains for most of 2024. More recently, JN.1 has been usurped by its own children, specifically variants like KP.2, KP.3, and LB.1, according to the most recent data from the CDC. These three variants are collectively called the FLiRT variants because of shared traits at specific positions of the spike protein: F shifts to L while R shifts to T.
These changes may seem small—they are microscopic—but they can give the virus an increased ability to evade immunity and increase its transmissibility, allowing it to spread more easily from person to person. To use the key metaphor, immunity is a bit like changing the locks when a SARS-CoV-2 virus attacks us. But they are clever locksmiths who keep making new and improved sets of keys.
“The LB.1 variant has the potential to infect some people more easily because of a simple deletion in a spike protein,” Dave Daigle, deputy director of the CDC’s Center for Global Health Communication, told Salon. “It’s present in multiple JN.1 lineages.”
“However, there is currently no evidence that LB.1 causes more severe disease,” Daigle noted. “Most key indicators of COVID-19 show low levels of activity nationwide, so the total number of infections this lineage can cause is likely low. Hospitalizations and deaths associated with COVID-19 remain low. CDC will continue to track SARS-CoV-2 variants and work to better understand the potential impact on public health.”
Rajnarayanan said the KP.3 lineage is “particularly concerning” because it appears to be more immune evasive than other circulating lineages. “KP.3.1 appears to have a significant growth advantage over other circulating lineages,” he said.
We now know why the number of cases seems to be rising again. But the big question is whether this will translate into different symptoms or an increase in the serious consequences of the disease, namely hospitalizations and deaths.
“I don’t think the virus is less (or probably more) dangerous per se today, and it’s certainly wrong to think that viruses always evolve to become more benign,” Dr. T. Ryan Gregory, an evolutionary and genomic biologist at the University of Guelph in Canada, told Salon. “The main reason we’re seeing far fewer severe acute infections is that there’s some level of immunity in the population from previous infection and (increasingly) from vaccination.”
However, Gregory noted that this immunity wanes over time and the virus continues to evolve toward immune evasion.
“The LB.1 variant has the potential to infect some people more easily.”
“Vaccination uptake is extremely low these days, which means that any immunity that is maintained will come primarily from reinfection,” he said. “That means more variant evolution, more risk of long COVID, etc. It’s always important to emphasize that severe acute respiratory disease (SARS S, A, and R) is not the only problem. There’s also long COVID and increased risk of all sorts of cardiovascular, metabolic, neurological, and other diseases.”
Another outstanding question is whether current or future vaccines can cope with these new strains of SARS-CoV-2.
“Currently available vaccines target XBB.1.5 (Kraken), which has not been in circulation for some time,” Gregory said. “These older vaccines work, although not as well, against JN.1 (and probably less so against KP.2, KP.3, and LB.1).”
According to NBC News, the U.S. Food and Drug Administration (FDA) is expected to approve updated vaccines this fall, advising drugmakers to target the KP.2 strain. The FDA has apparently reversed course after initially recommending vaccine developers target JN.1 instead.
“It looks like the updated Novavax vaccine will target JN.1 while the mRNA vaccines could target JN.1 or KP.2,” Gregory said. “JN.1 itself is no longer very common and the mutations in KP.2, KP.3, and LB.1 certainly matter. So it would make sense for them to at least include the F456L mutation (referring to FL in FLiRT) so that they are not so far behind the virus by the time the updated vaccines are rolled out.”
Meanwhile, cases could also be going unnoticed because we are doing far less testing and monitoring of the virus than in previous waves. Gregory said: “We have yet to learn that COVID is not seasonal – there can be surges at any time of year, including summer. It’s not just the US right now – there are surges in Europe (summer) and Australia (winter).”
“We are not tracking COVID as comprehensively as we used to,” Rajnarayanan said. “Despite this, we have several indicators that suggest increased transmission: Wastewater surveillance is showing increasing levels of the virus. Positive test rates are increasing in some areas, such as California (from 3% to 7.5%). There is potential for underreporting due to reduced testing and surveillance. Changes in reporting requirements, particularly negative tests, are not being adequately reported.”
While we don’t know the true extent of this surge, the advice to protect yourself is the same as before: “If you have symptoms, get tested and stay home until you are symptom-free,” Rajnarayanan said. “This will help prevent the spread to vulnerable people. Wear a mask if you are sick and must go out (avoid crowded areas). Wear a mask when traveling. Don’t make fun of people who wear masks. Be accommodating and courteous.”
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