Omicron is still the dominant coronavirus variant around the world. The first case was confirmed in South Africa in November 2021, and since then the family has kept splitting into new subvariants. By April 2023 the dominant and most contagious one globally was XBB.1.5, according to Ada Health.
By September 2023, 99.9% of the variants circulating in the United States were descendants of the Omicron strain. The World Health Organization had a watch list. XBB.1.5, XBB.1.16 and EG.5 were variants of interest. BA.2.86, DV.7, XBB, XBB.1.9.1, XBB.1.9.2 and XBB.2.3 were under monitoring.
The subvariants with nicknames
XBB.1.5, nicknamed Kraken, spreads quickly. There is no evidence that it causes more severe disease than other Omicron subvariants.
XBB.1.16, or Arcturus, can also spread fast and carries some risk of getting past immunity built through vaccination and earlier infection. Its severity is relatively low. One quirk: it can bring on conjunctivitis, or pink eye, with red, itchy, watering eyes and sticky eyelids. Because hay fever can look similar, telling COVID-19 and allergies apart matters.
EG.5, nicknamed Eris, made up 21.9% of COVID-19 cases in the United States at the time. It transmits easily, and there is a greater chance it can slip past immunity.
What an infection looks like
Omicron tends to be milder than Delta was. It can still put people in hospital and still kills some of them. Symptoms sit mostly in the upper respiratory tract and often resemble a common cold. Loss of smell and taste, common with earlier variants, shows up less often, which makes Omicron harder to spot.
The first signs usually include a sore throat, fever, cough, headache, muscle aches and fatigue. For BA.5, runny nose is on the list too. Symptoms generally worsen over the first few days, then fade. Adults notice them more than children do, and some people of any age have no symptoms. People are most infectious in the 48 hours before symptoms begin and for the first 5 days afterward.
Doctors usually diagnose it with a PCR test on a nose or throat sample. Rapid antigen tests are less sensitive. Genome sequencing can identify the variant, but it is mostly done to track spread, so a patient’s own result rarely names the subvariant.
Treatment and when to call a doctor
Most cases are mild and clear up on their own. Pain relievers such as paracetamol, ibuprofen or naproxen can help, as can drinking enough water, especially with a fever. Cough medicine helps, and sitting upright rather than lying down eases a cough.
Vaccines still protect against serious illness and death from Omicron. Reinfection is possible, though, and the risk rises when a new variant arrives that can evade existing immunity. People whose symptoms keep getting worse, or who still feel unwell weeks later, may have long COVID. That is a reason to see a doctor. The encouraging part is that most people recover fully, and anyone unsure about medication should talk to their doctor.
