CAPE TOWN, South Africa — Omicron appears to cause less severe illness than earlier variants of the
coronavirus but is more resistant to the two-dose Pfizer-BioNTech vaccine widely used in South Africa, according to a
major private study of the variant.
The study by Discovery Health, South Africa’s largest health insurer, showed that risk of hospital admissions among adults who developed covid-19 was 29 percent lower than in the initial pandemic wave that emerged in March 2020.
Discovery Health provided conflicting information about the size of the study. In the initial release, the company said the study was based on 211,000 positive test results in South Africa, of which 78,000 were attributed to omicron. A subsequent correction to the release removed the word “positive” from the test results and said the change “does not affect any of the calculations.” Later information provided by a Discovery Health spokeswoman put the number of total cases at 78,173, of which 19,070 tests were positive during the “omicron period” from Nov. 15 to Dec. 7. The company did not respond to requests for further clarification.
The study found that the vaccine from U.S. pharmaceutical giant Pfizer and German partner BioNTech provided just 33 percent protection against infection, much less than the level for other variants detected in the country.
At the same time, the vaccine may offer 70 percent protection against being hospitalized with omicron, the study found, describing that level of protection as “very good.”