Pfizer double-shot vaccine helps keep patients out of hospital

People fully vaccinated with the double-shot Pfizer vaccine are 70% less likely to contract severe Covid-19 requiring hospital admission in the current wave driven by the Omicron variant, a large real-world study by Discovery Health and the SA Medical Research Council (SAMRC) shows.

Discovery, SA’s largest private medical aid administrator, worked with the SAMRC to analyse the data, which was based on three weeks of the Omicron variant’s spread in SA.

The medical aid administrator has access to 3-million medical aid members’ records besides laboratory tests and hospital results.

The news about a high level of immunity, milder infections and the effectiveness of vaccines against serious illness comes as the national coronavirus command council (NCCC) is set to discuss more restrictions as case numbers rise in SA.

Preliminary results of the world’s “first at-scale real-life study” based on infections in real time show the risk of hospitalisation of patients with the Omicron variant is lower in SA than with previous variants of concern, but the data is still new and must be updated. Those who are admitted to hospital are often in a less serious condition than was the case with earlier variants of the coronavirus.

The study found that people infected with the Omicron variant are 29% less likely to require hospitalisation than during the first wave of Covid-19 in SA. However, the study’s results can’t be extrapolated to the rest of the world, where the percentage of populations with Covid-19 infections has been lower.

At least 70% of South Africans are estimated to have been exposed to the coronavirus, which indicates a high level of natural immunity in the population, in addition to the number of people who have been vaccinated.

SAMRC CEO Glenda Gray, who was involved in analysing the data, said the fact that the vaccines are preventing severe illness from the Omicron variant is “heartening”. She cautioned that more data is needed from the rest of the world before it can be concluded that Omicron leads to milder infections.

The data published on Tuesday shows the vaccine provides only about a 30% lower chance of becoming infected with the Omicron variant than unvaccinated people. Protection via the vaccine also wanes, so people who received their shots more than four months ago have even less protection.

Discovery also shared data from the Mediclinic hospital group, which owns a network of private doctors’ practices, showing that mild Covid was typically experienced by patients for only three days, starting with a scratchy, sore throat.

Despite the Pfizer jab being less effective against Omicron, Discovery CEO Ryan Noach said the company is seeing a “delinking” of the infection curve — the number of infections is rising but deaths and hospital admissions aren’t rising proportionately.

Noach said people who are fully vaccinated with double-dose Pfizer-BioNTech shots have “high levels of protection from serious illness ... across age groups and in the face of a range of chronic illness”.

But Reuters reported the risk of reinfection with Omicron is “relatively high” among those who have previously been infected with other variants.

The Mediclinic data shows 16% of patients currently admitted to intensive care units for severe Covid-19 are vaccinated.

Data on Omicron also shows children have a 20% higher chance of being admitted to hospital. “It may sound significant, but the absolute number of children in hospital is low,” said Noach. “There is no reason to panic in this regard.”

childk@businesslive.co.za