South Africa Omicron

South Africa illuminates our future

South Africa, omicron situation and trends

Cases, + 26,976

Will increase for the next few weeks

Positivity, 32.2%

Deaths, + 54

Professor Shabir Madhi

Gauteng

Cases probably peaked

More transmissibility

Combined with more population prior immunity

Three to four weeks, down from 8 weeks in previous waves

Uncoupling of cases severe disease and death rate

Delta

20,000 reported cases per day resulted in with 250 to 300 deaths

Omicron

Deaths 10 times less

Omicron not less virulent

But more community immunity

Antibodies and T cells

Omicron is antibody evasive

T cytotoxic immunity is relatively well conserved

This is what is causing the uncoupling

T cells come from infection and vaccination

Gauteng, serum survey 73% have been infected by the virus, this has led to a lot of T cell immunity

Both will protect against severe disease

Data from the first three weeks of the Omicron-driven wave in South Africa

Data, spanning clinical records, vaccination records, pathology test results

3.7 million people

Omicron: A highly transmissible variant causing rapid community spread

The Omicron variant of SARS-CoV-2

Fuelling South Africa’s fourth wave

Genomic Surveillance, Omicron over 90% of new infections

Has displaced Delta variant

The Omicron-driven fourth wave has a significantly steeper trajectory of new infections relative to prior waves.

National data show an exponential increase in both new infections and test positivity rates

Vaccine effectiveness during the current Omicron wave

SAMRC, n= 211,000 positive tests

41% from adult members who had received two doses of the Pfizer

78,000 of these COVID-19 test results were attributed to Omicron infections

To-date laboratory analysis has provided early insights into potential reduction in the effect of neutralising antibodies against the Omicron variant

Two doses of the Pfizer

Two-dose Pfizer-BioNTech vaccination provides significant protection against hospitalisation in individuals with Omicron variant infection

33% protection against infection, relative to the unvaccinated

(down from 80% protection against infection)

70% protection against hospital admission

(down from 93% with delta)

Protection against hospital admission is maintained across all ages

Protection against admission is consistent across a range of chronic illnesses

Diabetes, hypertension, hypercholesterolemia, cardiovascular diseases

Reinfection risk

Omicron reinfection risk significantly higher compared to prior variants

Overall, the risk of re-infection (following prior infection) has increased over time

Infected with Delta, a 40% relative risk of reinfection with Omicron

Infected with Beta, a 60% relative risk of reinfection with Omicron

Infected in first wave, a 73% risk of reinfection

Risk of severe disease and hospitalisation significantly lower in Omicron infection compared to prior variants

This lesser severity could, however, be confounded by the high seroprevalence levels of SARS CoV-2 antibodies in the general South African population

Risk of hospital admission among adults diagnosed with omicron is 29% lower

Hospitalised adults, lower propensity to be admitted to high-care and intensive-care units, relative to prior waves

Preliminary observations on Omicron experience in children

Under 18 have a 20% higher risk of admission when infected with Omicron

Also increase in admissions for children under five

Many are incidentally discovered in hospital

Children were 51% less likely to test positive for COVID-19 relative to adults in the Omicron period

Where children require admission for complications of COVID-19

Bronchiolitis

Pneumonia

Severe gastrointestinal symptoms and dehydration

The majority of children present with mild disease, with symptoms such as a sore throat, nasal congestion, headache and fever that resolves within three days