The omicron variant appears to cause less severe disease than previous versions of coronavirus, and Pfizer vaccine seems to offer less defense against infection from it but still good protection from hospitalization, according to an analysis of data from South Africa, where new variant is driving a surge in infections.While findings released Tuesday are preliminary and have not been peer-reviewed — the gold standard in scientific research — they line up with other early data about omicron’s behavior, including that it seems to be more easily transmitted. A two-dose Pfizer-BioNTech vaccination appeared to provide just 33% protection against infection during South Africa’s current omicron wave, but 70% protection against hospitalization, according to analysis conducted by Discovery Health, South Africa’s largest private health insurer, and the South African Medical Research Council.