In this file photo, flu and coronavirus (COVID-19) vaccine signage is seen at a Duane Reade by on Broadway on January 05, 2023 in New York City. Credit: Michael M. Santiago | Getty Images via TNS

As many hope COVID-19 would vanish, a new variant has surfaced and threatens another wave of mild sickness. 

Omicron XBB.1.5 has been affecting families across the U.S. since September 2022, and the Centers for Disease and Control estimates that an increasing majority of infections in the U.S. are from the fast-spreading variant.

Dr. Carlos Malvestutto, an associate professor of infectious diseases and physician at the Wexner Medical Center at Ohio State, said due to constant mutations, there are many different variants and subvariants of COVID-19. 

Since making its mark in the U.S. in the early months of 2020, over 1.1 million people have died of COVID-19 with over 102 million cases reported, according to the CDC. Though the new Omicron variant is more contagious than the previous variants, it is not as deadly or severe. 

Omicron XBB.1.5 has minor symptoms, and less patients will contract pulmonary disease, Malvestutto said.  

“The patients are presenting with sore throat, nasal congestion, fatigue and headaches,” Malvestutto said. “Less of this horrible bilateral involvement on the lungs.”

Malvestutto said five days is the quarantine recommendation for COVID-19. Those infected are most contagious during that time.

According to John Hopkin’s School of Public Health, those who have been infected by a different Omicron variant are likely to get reinfected with this variant because Omicron XBB.1.5 is more “immune-evasive.” 

“For most people, this will be the period when it’s the highest risk of transmission to others, so the recommendation is to isolate, wear a high-quality mask around home and in public,” Malvestutto said. “After five days, if they’re not having significant symptoms, then they can stop isolating.”

If someone is experiencing a fever, they are encouraged to isolate beyond the typical five days, because fevers are an uncommon symptom of XBB.1.5, Malvestutto said. The moderate symptoms, such as shortness of breath or severe illness, require a 10-day quarantine period, he said. 

Around day five of isolation, Malvestutto said it is recommended that people self-administer an at-home test to be sure they are no longer contagious. He said the CDC tracks the emergence of the variants, when they’re present and at low frequency.

“Overtime, when they see more of these, then they can estimate or model what the following weeks are going to look like,” Malvestutto said. “Based on this, we estimate that we are getting to a higher percentage of [circulating viruses].”

In order to keep from getting Omicron XBB.1.5, the bivalent vaccine, geared towards newer variants, has much better coverage than previous vaccines, Malvestutto said.

“That’s a big advantage of the bivalent vaccine, which is why it is strongly recommended particularly for people who are at risk of COVID complications,” Marvestutto said.

Phillip Anderson, pharmacist at the Ohio State Student Health Center, said in an email the bivalent COVID-19 booster shot helps fight against the original virus strain and a component of the Omicron variant. 

The CDC reports that 69 percent of Americans complete the primary series of vaccines, but only 15.5 percent received an updated bivalent booster dose. 

Anderson said he recommends that people get the recent booster due to studies showing that primary vaccines do not completely prevent someone from being infected with a COVID-19 variant, only severe illnesses.

“The updated booster provides added protection against the recent Omicron subvariants that are more contagious than previous ones,” Anderson said. “The recent subvariants BA.4 and BA.5 are very closely related to the original variant, Omicron, with very small differences between itself and the original variant.”