South Africa says vaccines and natural immunity limit latest Covid wave

According to the country’s health minister, vaccines and high levels of previous exposure to coronavirus in South Africa appear to protect against the more severe symptoms seen in the previous three waves of the pandemic.

The claims that previous exposure to another variant of the coronavirus – or vaccination – could provide protection against the Omicron variant echoes an analysis by South African experts earlier this week that suggested that previous exposure or vaccination may provide some degree of protection against the virus. gave serious illnesses.

This is supported by several reports, including by public and private healthcare providers, which point to lower hospital admissions during the current wave.

Echoing the findings of Shabir Mahdi, a vaccine expert at the University of Witwatersrand, Johannesburg, Health Minister Joe Phaahla told a news conference: “We believe that Omicron is not necessarily less virulent, but . .. vaccination coverage [and] … natural immunity of people who have already been in contact with the virus also contributes to the protection. That’s why we see mild illnesses.”

While there has been an increase in hospitalizations and deaths in South Africa in recent days, driven by the rise in cases of the Omicron variant, along with ongoing infections from the Delta variant, health officials say it remains at lower levels than in earlier waves.

Michelle Groome, of the National Institute of Communicable Diseases, said:[We are] we are starting to see a slight increase in deaths nationwide, but again, this level is much lower even than in the reference period we saw between the second and third wave.” She added that these were “relatively small increases in deaths.”

Wassila Jassat, also of the NICD, said the number of people needing oxygen was lower than in any previous period. “Patients seem to stay for a shorter duration,” she said.

Phaahla said early indications were that infections may have peaked in Gauteng province, where cases initially spiked. However, the latest figures from the NICD showed that Gauteng continued to be responsible for the most new Covid infections on December 16, at 27%, followed by KwaZulu-Natal (23%) and Western Cape (19%).

His comments came as the G7 group of countries called the Omicron variant the “greatest current threat to global public health”, saying it was “more important than ever” for countries to “work closely together”.

While South Africa’s experience with Omicron around the world has been closely watched for evidence of how infections may progress, experts say populations with higher numbers of older and more vulnerable people may experience it differently.

Given how contagious the Omicron variant is, one of the most pressing concerns is that the very rapid and concentrated burst of infections it causes could overwhelm health systems due to its sheer number.

However, Friday’s South African press conference gets to the heart of some of the unknowns about the Omicron variant.

While Omicron has been found to be more contagious and better able to evade neutralizing antibodies provided by vaccines and previous exposure, questions remain as to whether other aspects of the body’s acquired immunity to Covid-19 are possible. have a soothing effect on more serious illnesses.

According to some experts, while Omicron is more easily able to evade key neutralizing antibodies that attach to the virus’s spike protein, other tools in the immune system’s defense repertoire, including so-called killer T cells, can still do their job. do work.

A presentation given earlier this week by Wendy Burgers of the University of Cape Town at a World Health Organization symposium on evidence that Omicron evades immunity indicated that preliminary research seemed to suggest that the body’s T-cell response remained strong against Omicron. .

That remains up for debate, however, as England’s chief physician this week told the House of Commons that there was a lack of “very good T-cell studies” to establish whether this was happening.

South Africa has given 44% of the adult population at least one dose of Covid-19 vaccine, more than many African countries but well short of the government’s target for the end of the year. Among the over-50s, the vaccination rate is more than 60%.

The latest information from South Africa came as Omicron continued to spread rapidly around the world with India – which suffered a devastating Delta outbreak earlier this year – reporting 101 cases in 11 provinces.