The death rate in those infected with the Omicron coronavirus variant in South Africa peaked at 14-15% of the rate seen when the country was experiencing a wave dominated by the Delta variant, according to the National Institute for Communicable Diseases.
Of those in the hospital with Covid-19 during the country’s fourth wave, about 32% had severe disease compared to 63% in the Delta-led third wave, Waasila Jassat, a public health specialist at the NICD said in an online presentation on Friday. Hospital admissions peaked at about 60% of the Delta wave, she said.
Since being identified by South African scientists on 25 November, the Omicron variant fuelled record daily case numbers and accounts for more than 98% of cases in the country. In the last two weeks, there has been a sustained drop in cases, although the decline hasn’t been as rapid as the steep rise at start of wave.
Still, with the surge having largely peaked, about 580 000 people have tested positive for Covid-19 in the latest wave, compared to 1.2 million in the Delta wave.
The percentage of people in the hospital with Covid-19 in the Omicron wave that have died has also dropped significantly, to about 10%. That compares to 26% in the Delta wave.
“What’s also very striking is that even using excess mortality, we didn’t see the rise in deaths as we did in the second and third waves,” Jassat said.
Excess mortality is a measure of the number of national deaths measured against a historical average. It is considered to be a more accurate measure of the impact of Covid-19 than official statistics. Excess deaths during the Omicron surge peaked at about a sixth of those of the third wave.
Those older than 20 years of age, of which about 30% are vaccinated, accounted for a smaller percentage of the fourth wave hospital cases. This may partly be because only about 4.5% of people under 20 years old are fully vaccinated.
“There was a trend toward younger people making up a bigger proportion of admissions in this fourth wave,” she said. “However, all indications are that the severity among younger people was also lower in the fourth wave as compared to the first, second and third wave.” — Janice Kew and Antony Sguazzin, (c) 2022 Bloomberg LP