Dec 14, 2021
Pfizer stops 70% Omicron hospitalizations in study
John O'Connell discusses Pfizer
Pfizer Inc. and BioNTech’s COVID-19 vaccine, as well as the shot developed by Johnson & Johnson, appear to prevent severe disease from the omicron variant, South African studies show.
The two-shot Pfizer course may offer 70 per cent protection against being hospitalized with the variant that is driving the country’s fourth wave of infections, Discovery Health Ltd., the country’s largest medical-insurance provider, said on Tuesday.
That protection is maintained across age groups and in the face of a range of chronic illnesses, said Ryan Noach, the chief executive officer of Discovery Health. Pfizer is 33 per cent effective against infection by the omicron variant, he said in a briefing.
The Discovery study included about 78,000 COVID-19 positive test results for omicron infections from Nov. 15 to Dec. 7 in South Africa, the epicenter of the current omicron wave. Clinical records, vaccination records and pathology-test results were examined.
While there is a relatively high risk of reinfection with omicron, hospital-admission risk linked to omicron infection was 29 per cent lower overall for the general adult population, compared with South Africa’s first wave of infection in mid-2020, Noach said.
Still, not withstanding the apparent lower severity of omicron, the sheer volume of infections could put “health systems under incredible pressure,” he said.
Part of the reason for the lack of severe illness among residents of South Africa could also be the level of prior infection, where 70 per cent or more of the population has been exposed to COVID-19 at some stage during the past 18 months.
“South Africa has seroprevalence data that shows up to 80 per cent of the population in some parts of South Africa” have had a prior infection, Glenda Gray, president of the South African Medical Research Council said at the same briefing. “We don’t know how omicron is going to evolve in countries with low vaccination or prior infection rates.”
No one has died from an infection with the strain, Gray said, citing a separate South African study that includes hundreds of thousands of health workers that received the J&J shot. More details from that study will be made available in coming days, she said.