Skip to content

Virus Experts Just Issued This "New Wave" Warning

The pandemic is still evolving.
FACT CHECKED BY Emilia Paluszek

Don't think the COVID-19 pandemic is winding down—it might be evolving to become more serious, experts warned this week. BA.4 and BA.5 are the latest subvariants of the highly contagious Omicron COVID variant. They seem to have some characteristics that are concerning to health officials, and they might amount to a new COVID wave altogether. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


What Are BA.4 and BA.5?

Scientists and microbiologists with PPE suit and face mask hold test tube and microscope in lab

BA.4 and BA.5 were designated "variants of concern" in late May. They were first detected in South Africa in January. Today, they're rapidly gaining a foothold in the U.S. The CDC said Tuesday that BA.4 and BA.5 now account for 21% of COVID cases nationwide. The two subvariants seem better at escaping protection from vaccines and immunity from previous infections, experts say.

"I'm very concerned," Dr. Gregory Poland, head of Mayo Clinic's vaccine research group, told Reuters this week.

Experts say that BA.4 and BA.5's ability to evade layers of protection make reinfections more likely, which may result in another wave of the virus.   


Could BA.4 and BA.5 Cause More Severe Illness?

Woman being sick having flu lying on sofa looking at temperature on thermometer. Sick woman lying in bed with high fever.

Overall, the Omicron variant has produced milder illness than previous COVID variants like Alpha and Delta. That's because Omicron primarily affects the upper respiratory tract, causing cold- or allergy-like symptoms, instead of settling into the lungs, which made early variants so deadly. 

But this week, the Guardian reported on research from the University of Tokyo that suggests the subvariants BA.4, BA.5, and BA.2.12.1 may have evolved to again target lung cells instead of upper respiratory tract tissue, making them similar to Alpha or Delta. "Our investigations suggest that the risk of [these] Omicron variants, particularly BA.4 and BA.5, to global health is potentially greater than that of original BA.2," said the study's lead author, Kei Sato.

"It looks as though these things are switching back to the more dangerous form of infection, so going lower down in the lung," said Dr. Stephen Griffin, a virologist at the University of Leeds.

As of now, health officials say that BA.4 and BA.5 don't seem to cause more severe disease than other forms of Omicron, and vaccines and boosters continue to provide robust protection against serious illness. But unvaccinated people are vulnerable, and the virus's continued ability to mutate means the pandemic is not over (nor is COVID turning into the common cold).


How to Stay Safe Out There


Follow the fundamentals and help end this pandemic, no matter where you live—get vaccinated ASAP; if you live in an area with low vaccination rates, wear an N95 face mask, don't travel, social distance, avoid large crowds, don't go indoors with people you're not sheltering with (especially in bars), practice good hand hygiene, and to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.

Michael Martin
Michael Martin is a New York City-based writer and editor. Read more about Michael