Scientists reported that a patient from the UK with a weak immune system was treated with COVID-19 for nearly a year and half. This highlights the importance of protecting vulnerable individuals against the coronavirus.

It’s impossible to determine if it was the longest-lasting COVID-19 infected because not everyone is tested, particularly on a regular basis such as this.

However, at 505 days, it “certainly seems to be the longest reported infected,” Dr. Luke Blagdon Snell of Guy’s and St. Thomas’ NHS Foundation trust, said.

Snell’s team will present “persistent COVID-19” cases to an infectious disease meeting in Portugal this weekend.

The researchers looked at whether mutations and variants can occur in super-long infections. Nine patients were included in the study, all of whom had been positive for the virus for at most eight weeks. All of them had weak immune systems due to organ transplants, HIV, or other treatments. Privacy reasons prevented the identification of any.

Multiple tests revealed that their infections lasted an average of 73 consecutive days. Two of them had been infected for over a year. Researchers previously stated that the longest known case of the virus that was confirmed by PCR testing lasted 335 day.

The persistence of COVID-19 is uncommon and distinct from long COVID.

Snell stated that although symptoms may disappear after a long COVID, the majority of people assume the virus is gone. It is a persistent, active replication of the virus.

Researchers checked the genetic code of each patient every time they tested them to ensure that it was the same strain. Genetic sequencing revealed that the virus evolved over time and mutated as it changed.

Snell stated that the mutations they received were very similar to those that later appeared in many variants. However, none of the patients produced new variants that are of concern. It is also not clear that they transmitted the virus to others.

The person who had the longest-lasting known infection was found to have tested positive for the drug remdesiver in early 2020. He died in 2021. Researchers refused to identify the cause of death, but said that the victim had multiple other illnesses.

Five patients survived. Two patients were able to clear the infection without treatment. Two others had it cleared up after treatment. One patient still has COVID-19. The patient’s infection had been present for 412 days at the last follow up earlier in the year.

Researchers believe that more treatments will soon be available to people suffering from persistent infections.

Snell stated, “We need to be aware that some people are more vulnerable to these problems such as persistent infection and severe diseases.”

Experts say persistent infections are very rare. However, there are many people who have compromised immune systems and are still at risk for severe COVID-19. They are trying to stay safe since governments removed restrictions and masks began coming off. It’s difficult to identify them, according to Dr. Wesley Long of Houston Methodist, Texas.

He said, “Making friends in crowds is considerate and a way to protect others.”