In fall 2025, rumors spread that the strain of the virus in circulation that causes COVID-19 had “very different signs” compared to other strains of the virus. Referring to it as “COVID-25,” people said doctors were warning about new symptoms and shared the “signs” on social media.
For example, a man identifying himself as “Dr. Tony” (we reached out to him, but could not confirm whether he is a medical doctor), posted a video on TikTok listing some of these supposed “signs” (archived):
The video had amassed 3.1 million views and 114,500 likes as of this writing. The man did not speak, but the caption on the video said that “the symptoms are not the same ones we used to know.” The video then listed the following symptoms:
- Extreme fatigue — like you haven’t slept for days.
- Sore throat and a dry cough that can last for weeks.
- Mild fever around 100-101°F (37.8-38°C), coming and going for no clear reason.
- Intense headache — feels similar to a migraine.
- Loss of appetite, nausea, and sometimes stomach pain.
The man then encouraged his followers to search the terms “latest covid symptoms 2025.”
Similar lists for “new” COVID-19 symptoms appeared on TikTok. The same video as above also appeared on Substack and X.
There was no “COVID-25” in circulation in the fall of 2025, though. Instead, there were two relatively new strains of the SARS-COV-2 virus, which causes COVID-19. Both of these strains were subvariants of Omicron.
While it is true one of these two strains caused one distinctive symptom (discussed below), that symptom was not on “Dr. Tony’s” list. Further, the rest of the supposed “new” symptoms also occur with other strains of SARS-COV-2. (Note that it is often the case that certain viral strains cause symptoms that are specific to the strain.)
Reputable sources that shared COVID-19 common symptoms listed several or all of the symptoms the man mentioned in his video. For example, the Centers for Disease Control and Prevention (CDC) said that possible symptoms could include the following:
- Fever or chills
- Cough
- Shortness of breath or difficulty breathing
- Sore throat
- Congestion or runny nose
- New loss of taste or smell
- Fatigue
- Muscle or body aches
- Headache
- Nausea or vomiting
These, the CDC website added, could come with varying degrees of severity. Severe illness can require hospitalization. Comparing the supposed “new” symptoms to the ones in this list showed that they were not unusual.
Meanwhile, experts said that two new strains of SARS-COV-2 were circulating in 2025. One, the so-called “Nimbus” strain (NB.1.8.1), came with a characteristic “razor blade throat.”
Stony Brook Medicine said common “Nimbus” symptoms included:
- Severe sore throat (often felt while swallowing)
- Persistent fatigue
- Mild cough
- Nasal congestion or a runny nose
- Fever and muscle aches
- Sneezing
- Digestive symptoms like nausea or diarrhea (less common, but possible)
Another strain circulating in 2025 was the so-called “Stratus” strain (XFG). As of September 2025, it was outnumbering cases of “Nimbus” in part because it was better at evading the immune system, according to the Word Health Organization. This one included as a specific symptom a “persistent dry cough,” according to Stony Brook Medicine:
- Persistent, dry cough
- Tiredness or fatigue
- Fever
It could also include shortness of breath and chest tightness, in addition to loss of taste and smell and brain fog.
