Researchers in South Africa and around the world are conducting studies to better understand Omicron, and they will continue to share the results of these studies as they become available.
Transmissibility: Omicron’s transmissibility (i.e., ease with which it can be spread) is not yet known compared to its variants, including Delta. In areas of South Africa affected by this variant, the number of people testing positive has increased. However, epidemiological studies are ongoing to determine whether this is due to Omicron or other factors.
Severity of disease: There is no clear evidence that infection with Omicron causes more severe disease than infection with other variants, such as Delta. The preliminary data suggests that hospitalization rates are increasing in South Africa, but this may be due to an increasing number of people becoming infected than to a specific infection with Omicron. At this time, there is no evidence to suggest that symptoms of Omicron differ from those of other variants. Infections have been reported among university students-younger people who tend to have milder disease-but understanding the severity of the Omicron variant will take days to several weeks. COVID-19, including the Delta variant that is prevalent around the world, can cause severe disease and death, especially among the most vulnerable individuals, so prevention is essential.
Effectiveness of current tests: PCR tests continue to detect infections, including Omicron infection, as well as infections with other variants. Research is underway to determine whether there is an impact on other types of tests, including rapid antigen detection tests.
The World Health Organization is currently working with a wide range of researchers around the world to better understand Omicron. Studies currently underway or soon to begin will assess transmissibility, severity of infection (including symptoms), performance of vaccines and diagnostic tests as well as effectiveness of treatments.
The WHO encourages countries to collect and share hospitalized patient data through its COVID-19 Clinical Data Platform to describe clinical characteristics and patient outcomes more rapidly.
In the coming days and weeks, more information will become available. TAG-VE will continue to monitor and evaluate data as it becomes available and determine how mutations in Omicron affect the virus’ behavior.