With the new Omicron variant of coronavirus spreading across parts of the world, scientists have been weighing how long a patient should remain in quarantine. Earlier this month, the United States Centers for Disease Control and Prevention (CDC) backed its week-old guidance for people seeking to end their COVID-19 isolation at five days, adding they could take a rapid antigen test if they want to and can access one, but is not requiring that. Echoing US CDC’s advice, the United Kingdom also shortened its isolation period for COVID-19 to five days after testing positive.
However, a study by Japan’s National Institute of Infectious Diseases published on January 5 found that patients with the Omicron variant of COVID-19 shed the virus for much longer after symptoms emerged. The study mentions that the amount of viral RNA was highest three to six days after symptom onset, with a marked decrease only after ten days. This contradicts the recommended quarantine time period by the US and UK national health agencies.
CDC director Dr. Rochelle Walensky defended the five-day isolation period decision, as she told the New York Times that the recommendation was based on evidence that the majority of transmissibility lasts in the two days before symptoms and the two to three days after onset.
One of the reasons why the quarantine period has been reduced for the Omicron variant is the increase in vaccinated people. Chicago Department of Public Health Commissioner Dr. Allison Arwady told NBC, “It is taking less time from when someone is exposed to COVID to potentially develop infection. It is taking less time to develop symptoms, it is taking less time that someone may be infectious and it is, for many people, taking less time to recover. A lot of that is because many more people are vaccinated.”
However, Lawrence Young, a virologist and professor of Molecular Oncology at Warwick Medical School, England shares a different opinion. Speaking to Fortune, Young said, “What we’re going to do is run the risk of highly infectious people returning to work or school. The bottom line with this is this is not a scientific change or policy that is based on scientific evidence at all. It is based on the need to get people back to work.”
Most of the countries are not reducing their isolation period to five days like the US and the UK. According to Fortune, the minimum days of quarantine in most of the countries remains ten days. Meanwhile countries like Canada have reduced the quarantine period for vaccinated people to five days. In India the recommended period of isolation is 14-days.
