The most recent dominant variants of SARS-CoV-2, which causes COVID-19, are known as 'FLiRT' variants. This serves as a reminder that the virus is still present and some people are still suffering.
While most of the country and the federal government have put the pandemic behind them, the virus is changing and new variants are appearing.
The new variants have not been proven to cause more severe illness so far, and vaccines are still effective. However, there is uncertainty about how the virus may change and what might happen next.
According to the latest available data, weekly hospitalizations were at their lowest level since the beginning of the pandemic.
As of May 1, hospitals are no longer obligated to report COVID-19 hospital admissions, capacity, or occupancy data to the federal government.
The most recent data from the Centers for Disease Control and Prevention shows that the dominant variant KP.2 accounts for nearly 25 percent of all infections. KP.2 is a descendant of the JN.1 variant, which it has recently surpassed as the dominant strain. JN.1 accounts for 22 percent of all infections.
KP.2 is a member of a group of SARS-CoV-2 variants sometimes called 'FLiRT' variants. Other FLiRT variants, including KP.1.1, are circulating in the U.S. but are not yet as widespread as KP.2.
According to William Schaffner, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, the new variants are not substantially different from previous mutations of the virus. They are all subvariants of omicron and have spike protein mutations that make them more transmissible.
Schaffner stated that the new variants are highly transmissible but do not appear to cause more severe disease.
The spike protein mutations mean that vaccines and previously acquired immunity may not fully protect a person as they did against earlier strains. However, lab tests show there is still substantial protection against severe disease.
Schaffner mentioned that the virus is now endemic and needs to be managed routinely, like other serious seasonal respiratory infections. It is not expected to disappear.
Federal health officials are preparing for a fall vaccination campaign. The Food and Drug Administration has delayed an advisory committee meeting on the formulation of those shots until next month to gather more data on the circulating variants.
Officials aim to target the dominant variant with the newest vaccine, but this can be a moving target. There is likely to be a new dominant strain by the time the shots are manufactured and distributed, similar to what happens with the annual flu shot.
Vaccinations can prevent serious illness and hospitalization. Initial data from the CDC in February showed that the 2023 vaccine was approximately 53 percent effective at preventing symptomatic infection. These vaccines targeted the omicron variant XBB.1.5, which was the main variant in 2023 but was replaced by JN.1 shortly after the vaccines were introduced.
However, less than one in four U.S. adults received the vaccines last autumn, and there is worry that low vaccination rates combined with changing variants could lead to a surge in the summer.
The latest variant is also a reminder that some people are still experiencing long-term symptoms after having COVID-19.
This week, the National Institutes of Health announced that it was starting clinical trials to study potential treatments for long-lasting symptoms after a COVID-19 infection, including sleep problems, difficulty exercising, and the worsening of symptoms after physical or mental effort.
The new trials will include about 1,660 people at 50 research locations and will supplement six earlier investigations that are part of the NIH's Researching COVID to Enhance Recovery Initiative.
