There are eight different ways people experience long COVID symptoms, according to a new study from the National Institutes of Health's research initiative.

The big picture: The new study represents one of the most substantive findings on long COVID from the Researching COVID to Enhance Recovery (RECOVER) project, launched by the NIH in 2021.

• The findings, released on Nov. 17, come as scientists and medical experts warn that President Trump's cuts to the NIH last spring would severely impact the initiative's research.

Driving the news: In the new study launched in 2023, the researchers found that participants experienced long COVID in eight different ways and lengths of time.

• The study, published in the journal Nature Communications, featured 3,659 participants, 69% of whom were female, and 99.6% were studied during the Omicron variant era of the pandemic.
• The researchers measured long COVID experiences from three to 15 months.

Here's what to know.

Long COVID symptom timelines

The researchers found that people experienced symptoms in different ways.

• Some felt many symptoms quickly for short periods of time, while others felt symptoms rarely for long periods of time.

Here are the eight patterns outlined by the study:

• Symptoms remained high at all times with "persistent, high symptom burden."
• Symptoms fluctuated and only sometimes met the threshold for long COVID.
• Symptoms decreased over time.
• Long COVID symptoms started low for three months and then became nonexistent at six months.
• Symptoms increased over time with a "worsening, moderate symptom burden."
• Symptoms started low for three to 12 months, then increased after 15 months, likely driven by a "post-exertional malaise."
• Symptoms started generally low, but grew higher between three and 15 months without ever reaching the threshold for long COVID.
• Some experienced symptoms so infrequently they never met the threshold for long COVID.

What they're saying: The researchers said the identification of these paths is "critically important" for understanding long COVID and developing strategies to fight it.

Common long COVID symptoms

There are still many unknowns about the condition. This new study traces the trajectories of long COVID, but researchers are still unclear about the biological underpinnings of what even causes it.

Yes, but: Plenty of research has been done on which long COVID symptoms have emerged since the pandemic began, including:

• Exertion and fatigue.
• Brain fog.
• Dizziness.
• Gastrointestinal symptoms.
• Heart palpitations and chest pains.
• Changes in sexual desire.
• Loss of smell or taste.
• Thirst.
• Chronic cough.

Current state of COVID and variants

COVID activity is "growing" around the country, according to data from the Centers for Disease Control and Prevention released on Nov. 18.

• 19 states are seeing an uptick in COVID infections, per the CDC.
• COVID-19 cases are generally lower than the levels seen in 2024.

The CDC says the viral activity level in wastewater is "very low" with the XFG variant — otherwise known as the Stratus variant — being the most common version.

More from Axios:

Where the COVID surge is "very high" and what to watch for this winter

A guide to the new COVID vaccine recommendations

What to know about rising COVID-19 cases and the surging Stratus variant