Adrian Gore: World’s first Omicron data unpacked – we’re moving into different phase of pandemic

Being the epicentre of Covid-19’s new Omicron variant has its advantages. Especially when that nation is able to call on a world class healthcare multinational headquartered in the country. The Discovery Group, whose operations stretch from Shanghai to Sunderland and whose business partners include global giants Apple to Ping An, has long been a heavy investor into accumulating and analysing Big Data. Its considerable resources have been applied into analysing whether the science supports growing evidence that Omicron is a sheep in wolf’s clothing – or not. The results are heartening. In letter below that was sent to Discovery clients this morning, CEO Adrian Gore concludes “we are now moving into a different phase of the pandemic … I am cautiously optimistic …” That’s about as bullish a statement you’re likely get from this typically cautious actuary. – Alec Hogg

By Adrian Gore*

As you know, Discovery Health has released data analyses throughout the pandemic. Earlier today it shared the first at-scale analysis of the real-world impact of Omicron, based on 211,000 COVID-19 test results in South Africa, including collaboration with the South African Medical Research Council (SAMRC) to analyse vaccine effectiveness. This data is critical given South Africa is at the epicentre of the Omicron outbreak and given the urgency around establishing real-world data on the impact of Omicron. With Omicron now estimated to account for over 90% of new infections nationally, fuelling our fourth wave and a significant level of member concern, I want to share the highlights of this analysis with you.

In a nutshell, while Omicron seems to be more transmissible than previous variants, with a higher rate of reinfection following prior infection, its severity relative to prior variants seems less (fewer hospital admissions and a lower proportion of high care and ICU admissions compared to previous waves). In addition, vaccination remains effective in protecting against severe COVID-19 and consequent hospital admission, underscoring the importance of vaccinating and getting boosters as soon as they become available. Importantly, these preliminary findings relate to the very early period of the Omicron outbreak and could change with the extension of the wave.

Real-world data on Omicron is critical to guiding the global response

As South Africa’s largest private health insurance administrator, with more than 3.7 million health clients, we are in a unique position to update and inform on Omicron. This is due to both the dominance of the Omicron variant in South Africa and the richness and significance of our data, spanning clinical records, vaccination records and pathology test results drawn from Discovery Health’s database.

The analysis had two main objectives: First, we partnered with world-leading researchers from the South African Medical Research Council (SAMRC) to provide insights into Pfizer-BioNTech vaccine effectiveness against infections and severe disease linked to Omicron infection. This analysis included over 211,000 COVID-19 test results, 41% from adult members who had received two-doses of the Pfizer-BioNTech vaccine. Approximately 78,000 of these COVID-19 test results were attributed to Omicron infections, over the period 15 November to 7 December 2021. Second, Discovery Health in its own capacity explored several areas related to Omicron: rate of spread; severity of illness relative to prior waves; clinical manifestations; and the relative reduction of risk conferred by prior proven COVID-19 infection.


  1. Infectiousness: Omicron reinfection risk is significantly higher compared to prior variants

With each successive wave of COVID-19 infection in South Africa, Discovery Health teams have investigated the durability of immunity following previous infection with COVID-19 – that is, the risk of reinfection.

Overall, the risk of reinfection following prior infection has increased over time, with Omicron resulting in significantly higher rates of reinfection compared to prior variants.

  • People who were infected with COVID-19 in South Africa’s third (Delta) wave face a 40% relative risk of (re)infection with Omicron
  • People who were infected with COVID-19 in South Africa’s second (Beta) wave face a 60% relative risk of (re)infection with Omicron

Individuals who had a documented infection in South Africa’s first wave, and therefore were likely to have been infected with the ancestral or first version of the virus, face a 73% risk of reinfection relative to those without prior documented infection.

These changes in reinfection rates could be due to the characteristics of the Omicron variant, but are potentially also impacted by the durability of antibody-mediated immunity.

  1. Severity: Risk of severe disease and hospitalisation is lower in Omicron infection compared to prior variants

While we are witnessing a steep trajectory of new infections, indicating Omicron’s rapid spread, we are also seeing a flatter trajectory of hospital admissions, indicating lower severity. For example, adults in the Discovery Health population are experiencing a 29% lower admission risk relative to South Africa’s first wave of infection in 2020. Furthermore, hospitalised adults have a lower propensity to be admitted to high care and ICU, relative to prior waves.

These data insights correlate strongly with the anecdotal consensus shared by healthcare professionals treating COVID-19 patients in both the out-of-hospital and in-hospital settings. However, caution must be exercised in this regard considering that this data relates to the very early period of the Omicron-driven wave, and this severity picture may change over time. The majority of those requiring hospitalisation, exceeding 75%, are unvaccinated.

  1. Vaccine efficacy: Two-dose Pfizer-BioNTech vaccination provides significant protection against hospitalisation in individuals with Omicron variant infection

The results show that vaccinated individuals who received two doses of the Pfizer-BioNTech vaccine have 33% protection against infection, relative to the unvaccinated, in the first weeks of South Africa’s Omicron-driven fourth wave. This represents a significant reduction from the 80% protection against infection afforded during the earlier period, likely on the basis of lower antibody susceptibility, following the extensive spike protein mutations in the Omicron variant.

Encouragingly though, the analysis shows that these same vaccinated individuals who received two doses of the Pfizer-BioNTech vaccine have 70% protection against hospital admission in this same time period. Whilst protection against hospital admission reduced from the highs of 93% in South Africa’s Delta-driven variant, 70% is still regarded as very good protection.

Furthermore, protection against hospital admission is maintained across all ages, in people from 18 to 79 years, with slightly lower levels of protection for the elderly (67% in people aged 60 to 69 and 60% for people aged 70 to 79). Protection against admission is also consistent across a range of individual chronic illnesses (diabetes, hypertension, hypercholesterolemia, and heart disease).

  1. Preliminary observations on Omicron experience in children

Notwithstanding the fact that children continue to show a very low incidence of severe complications following COVID-19, Discovery Health’s data indicates that children under age 18 appear to have 20% higher risk of admission for complications of COVID-19, when infected with Omicron. Although 20% may sound significant, it is a relatively small increase in real terms of the actual admission rate. The analysis also showed that children were 51% less likely to test positive for COVID-19 relative to adults in the Omicron period.

The primary diagnoses on hospitalisation of children for complications of COVID-19 are bronchiolitis and pneumonia, often associated with severe gastrointestinal symptoms and dehydration. Most children present with mild disease, with symptoms such as a sore throat, nasal congestion, headache, and fever, which typically resolve within three days based on anecdotal consensus sourced from the treating healthcare professionals.

Vigilance and vaccination remain our primary means of overcoming the pandemic

The results of the analysis provide an excellent demonstration in a real-world setting that even with the advent of a highly transmissible new variant, vaccination (in this case, the Pfizer-BioNTech vaccine) continues to provide excellent protection against severe disease and hospitalisation.

We are hopeful that the current description of disease severity caused by the Omicron variant – mild disease for the most part – will remain unchanged. However, we remain concerned that health systems could still come under pressure considering the high rate of spread of Omicron, and consequent high sudden infection burden. Our teams will continue to closely monitor the progression of the fourth wave in this regard.

Given these results, we urge you to get vaccinated, and for those who have had their double dose of the Pfizer-BioNTech vaccine, we encourage you to get your booster dose as soon as the National Department of Health makes it available to you, likely in early January. In addition, please continue to adhere to the important non-pharmaceutical measures of mask wearing, social distancing, avoiding public gatherings, and hygiene precautions.

This is my last note for the year – a year which has been complex and tragic, but with the hope that we are now moving into a different phase of the pandemic. I am cautiously optimistic that if we achieve widespread vaccination, we can stave off the worst impacts of the pandemic, curbing loss of life and advancing the country’s recovery.

  • Adrian Gore is the co-founder and CEO of the Discovery Group. 

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