How will Omicron viral load help explain transmission, reinfections, breakthroughs?

In addition to the understandable immediate focus on immunological consequences of the mutations in Omicron for either vaccine-induced or natural immunity, the viral load of Omicron should also help us understand its transmission, reinfections and vaccine breakthroughs.

A template can be created for understanding the spectrum of clinical outcomes alongside antibody and T-cell immunologic findings, viral load peak and timeline findings. Into this template must be incorporated the large number of vaccines, the number and type of doses, the months since the last dose and the underlying immune status of individuals.

Similar considerations in this template should be included for persons never vaccinated. This never-vaccinated group should be analyzed separately according to whether or not they have survived a previous infection with a non-Omicron SARS-CoV-2.

Another group to analyze by viral load and immunity are people who have survived prior infection and also have been vaccinated with one or more doses, and when prior to their Omicron infection.

Other factors to include in this template are the timing of monoclonal antibodies and antiviral drugs, including the new oral drugs when they become available and are used.

Omicron viral load will be compared with that of Delta and ideally with earlier variants as much as possible if such data are comparable from different times and using different assays to measure viral load. Having multiple timepoints for viral load would be even more helpful, e.g., to determine peak viral load, its onset (before fever or any other signs of illness) and duration of viral load.

For example, one always crucial issue with SARS-CoV-2 is: How much asymptomatic, or presymptomatic, transmission of Omicron is occurring in different patient populations?

Surely viral load data is being generated now in multiple laboratories across the more than 40 nations and 17 U.S. states reporting Omicron as of today (Monday, Dec. 6).