What is known about Omicron?

It has been more than two weeks since South African scientists discovered the newly-emerged coronavirus variant Omicron, which is believed to be behind soaring infections in the country this festive season.

On November 25, a Network for Genomic Surveillance South Africa team led by Professor Tulio de Oliveira announced the discovery of the variant, which infected several people in Gauteng and led to several countries closing their borders to South Africa.

Since its discovery – what is known?

The variant has been described by health minister Joe Phaahla as the driving force behind the sharp rise in infections over the past four weeks, with Gauteng being the epicentre. This past weekend, the province recorded 34 487 infections – about 50% of national cases.

Omicron has driven a resurgence in Covid-19 cases nationally. The health department reported 89 651 cases nationally from November 7 to December 4.

While the discovery of this variant triggered the so-called fourth wave of infections, clinicians report most people admitted to Gauteng hospitals have shown less severe symptoms compared to previous waves.

This was according to the private hospital group Netcare’s CEO, Dr Richard Friedland, and Steve Biko Academic hospital CEO, Dr Mathabo Mathebula.

The less severity of sickness in hospitalisations and deaths have led to several scientists believing that vaccinations were still effective against Omicron.

Tshwane has been one region that recorded a slight rise in Covid-19 hospitalisations between November 11-28.

The slight increase in coronavirus hospital admissions in Tshwane consisted mainly of children under the age of two, and 87% of unvaccinated individuals. This was according to an early data analysis by the National Institute for Communicable Diseases (NICD).

The NICD’s Dr Waasila Jassat, like many scientists, warned that unvaccinated people would be more prone to severe disease and possibly death.

Most people admitted with severe disease are aged 60 and above, which was also not a significant margin.

A high rise in children admissions had the scientists concerned. This led to Jassat advising the health department to also prepare for paediatric support during the fourth wave.

How does the variant affect children?

Early data from hospital surveillance showed that the admissions were largely in children admitted for other reasons and testing positive incidentally, of short duration (3-4 days). They did not show features of severe disease. In Tshwane, Mathebula said 79% of the admissions were individuals admitted for other medical reasons, but who tested positive while in hospital. The hospitalisations of children in Tshwane over the past few weeks dropped from 14% to 11% to 8%.

The children at risk of severe disease and death are those under a year old, mainly due to their immature immune systems.

Children with comorbid medical conditions because of premature birth, diabetes, cancers, HIV and TB were also at risk.

It was not clear what was driving the apparent increase in the proportion of children admitted to hospital with Covid-19, Phaahla said. He said they expected the Omicron variant to behave in the same way as other variants with regard to children.

What are the symptoms?

Private and public hospitals said people who recently tested positive for Covid-19 had mild to moderate flu-like symptoms, such as a blocked or runny nose, headache and a scratchy or sore throat, cough, diarrhoea and vomiting.

The health department reported that many children had non-respiratory symptoms.

Is Omicron more transmissible?

Scientists have yet to clarify whether this variant is more transmissible. Phaahla said it seemed likely that Omicron was more easily spread from person to person compared to other variants, including Delta. He attributed this to the rapid rise of cases in Gauteng and Omicron has spread to most provinces.

Is it more severe?

The NICD’s Dr Michelle Groome said that according to preliminary hospital data, admissions reported no severity sicknesses amongst adults and children admitted for Covid-related sickness thus far. Phaahla said data suggested that there was a slight increase in hospitalisations nationally. This may, however, be due to increasing overall numbers of people becoming infected, rather than a result of a specific infection with Omicron.

If I was infected, can I be infected again?

Preliminary evidence suggests there may be an increased risk of re-infection with Omicron. People who have previously had Covid-19 could become re-infected more easily with Omicron, as compared to other variants.

A not-yet-peer-reviewed report on the risk of re-infection in South Africa reported a 2-3 times increased risk of re-infection.

(This is defined as a positive test after 90 days have passed from the last infection).

More information on this will become available in the coming days and weeks.

What is the effectiveness of Covid-19 vaccines against Omicron?

Scientists continue conducting studies to understand the impact of Omicron on vaccines in protecting against severe illnesses and death.

Phaahla said the current vaccines remained effective against severe disease and death. He said early studies have revealed that there is only some loss in the protection of the Pfizer vaccine against Omicron.