Not heavy viral load; studies say this is the reason why Omicron spreads so fast

The studies, cited by Nature, found that the viral load of people infected by Omicron was actually similar or less than those who were infected by Delta, the previous dominant strain of SARS-CoV-2.

The viral load of Omicron and Delta is almost the same and it is not the reason why Omicron rapidly surged across the world and became the dominant SARs-CoV-2 strain replacing Delta. According to Nature, two studies, yet to be peer-reviewed, have shown that the Omicron does not release a larger amount of viral load than Delta. It is spreading in lightning speed only because it is able to evade immunity -- either natural or generated by past vaccination.

People wait at a rapid testing site in Brazil. (REUTERS)

The results suggest that Omicron’s hyper-transmissibility does not stem from the release of large amounts of virus from infected people. Instead, the best explanation for its lightning-fast spread is its ability to evade SARS-CoV-2 immunity caused by either vaccination or past infection, Emily Bruce, a virologist at the University of Vermont in Burlington, said.

What is viral load? It is the amount of the virus in an infected person. The RT-PCR test reveals the viral load. The CT value of the RT-PCR test report indicates the viral load, the lower the value, the higher the viral load is.

To compare the viral loads, the researchers studied the PCR test results of the nose and throat swabs collected from infected individuals and found that those who had Delta had a slightly higher viral load than those who had Omicron. “I was really not expecting to see that,” Yonatan Grad, an infectious-disease specialist at the Harvard T. H. Chan School of Public Health in Boston, Massachusetts, said.