There are two new COVID-19 variants circulating, posing a threat of a summer surge.

The Centers for Disease Control and Prevention (CDC) have been tracking these variants, scientifically known as KP.2 and KP.1.1, since at least the start of 2024. These variants, nicknamed “FLiRT” due to their mutations, have been steadily growing in prominence. KP.2 is currently the dominant strain in the U.S., comprising almost 25% of the sequenced tests, while KP.1.1 makes up about 8% as of the end of April. Both are sublineages of the JN.1 lineage of the Omicron variant, which has been the main COVID variant for roughly three years.

Health officials consider KP.2 and KP.1.1 very similar to JN.1, with early data suggesting only a couple of changes in their spike proteins.

With the virus expected to spread as summer approaches, concerns are rising about whether the last vaccine dose received is still effective. Ultimately, it depends on when you got your last dose.

In the fall, an updated COVID vaccine was released. The CDC recommends that everyone 6 months old and older get the updated vaccines from Pfizer-BioNTech, Moderna, or Novavax. In February, a federal immunization committee recommended an additional dose for those aged 65 and up. Children between 6 months and 4 years old require multiple doses, according to the CDC.

Previously, health officials stated that COVID vaccines would provide protection from the virus for “several months.” In a February update on the latest vaccine booster available since September, the CDC noted that while it had been effective from September to January, they expected that protection would “decline over time” as seen with previous doses.

However, because the FLiRT variants are relatively new, there isn’t enough data to show whether the vaccine or immunity from a recent COVID case will provide effective protection against them.

Speaking with TODAY, Dr. William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center, said lab studies so far have shown vaccines and immunity may only provide partial protection. Late last month, the World Health Organization recommended that future COVID vaccine formulations be based on the JN.1 variant, a close relative of the FLiRT offshoots that have been prevalent in the U.S. in recent months.

As of Thursday, the CDC is reporting minimal COVID activity in wastewater nationwide, and virus-related hospitalizations and deaths, as well as the rate of patients visiting emergency departments testing positive for COVID, are down.

A spokesperson for the CDC told Nexstar that the agency is “working to better understand [KP.2 and KP.1.1]’s potential impact on public health,” but noted that based on lab tests, there are “low levels of SARS-CoV-2 transmission overall at this time.”

“That means that while KP.2 is proportionally the most predominant variant, it is not causing an increase in infections as transmission of SARS-CoV-2 is low,” the spokesperson added. “Based on current data, there are no indicators that KP.2 would cause more severe illness than other strains. The CDC will continue to monitor community transmission of the virus and how vaccines perform against this strain.”

It’s too soon to say whether a new COVID vaccine will be created for the summer months. While the CDC recently eased guidance surrounding COVID, the agency still recommends that everyone 6 months old and older get the updated COVID vaccine released in the fall if they haven’t already. Health experts also continue to encourage testing if you experience symptoms or are exposed, staying home if you’re sick, practicing good hygiene, and wearing a mask and social distancing when in public.