Saturday, 14 August 2021 19:27

By Lehlohonolo Lehana.

The National Institute for Communicable Diseases (NICD), reports 13,021 new COVID-19 cases that have been identified in South Africa, which brings the total number of laboratory-confirmed cases to 2,595,447. This increase represents a 21.6% positivity rate.

The majority of new cases today are from Western Cape (27%), followed by KwaZulu-Natal (26%). Gauteng Province accounted for 14%; Eastern Cape accounted for 10%; Mpumalanga accounted for 7%; Free State and North West each accounted for 5% respectively; Northern Cape accounted for 4%; and Limpopo Province accounted for 3% of today’s new cases.

NICD said a further 238 COVID-19 related deaths have been reported, bringing total fatalities to 76,869 to date.

Meanwhile as Covid-19 surged last year, governments worldwide touted the hope of "herd immunity," a promised land where the virus stopped spreading exponentially because enough people were protected against it. That’s now looking like a fantasy.

The thinking was that the pandemic would ebb and then mostly fade once a chunk of the population, possibly 60% to 70%, was vaccinated or had resistance through a previous infection.

But new variants like delta, which are more transmissible and been shown to evade these protections in some cases, are moving the bar for herd immunity near impossibly high levels.

Delta is spurring widening outbreaks in countries like the US and UK that have already been walloped by the virus, and presumably have some measure of natural immunity in addition to vaccination rates of more than 50%.

It’s also hitting nations that have until now managed to keep the virus out almost entirely, like Australia and China.

This month, the Infectious Diseases Society of America estimated that delta had pushed the threshold for herd immunity to well over 80% and possibly close to 90%.

Public health officials like Anthony Fauci have drawn controversy by shifting the goalposts over the past year, increasing the number of people who need protection before hitting herd immunity. Meanwhile, vaccine hesitancy and supply issues mean most countries won’t get close to even the original numbers.

"Will we get to herd immunity? No, very unlikely, by definition," said Greg Poland, director of the Vaccine Research Group at the Mayo Clinic in Rochester, Minnesota.

Even a vaccination rate of as high as 95% wouldn’t achieve it, he said. "It is a neck and neck race between the development of ever more highly transmissible variants which develop the capacity to evade immunity, and immunization rates."

Nature isn’t going to solve the problem, either. It’s unclear how long natural immunity gained by surviving Covid-19 will last, and whether it will be effective at fighting off new strains. Future variants, including some that could evade immunity even more efficiently than delta, raise questions about how – and when – this will be over.

"If it was as simple as getting the infection once means you are immune for life, that would be great, but I don’t think that’s the case," said S.V. Mahadevan, director of South Asia Outreach at the Center for Asian Health Research and Education at Stanford University Medical Center. "That’s a troubling problem."

Already there are signs that some people, and some places – like Brazil and other countries in South America – are being battered a second time by newer strains.

Without herd immunity, the virus could linger for decades in some form, possibly forcing the world’s most powerful nations to adjust their diverging strategies on opening borders and economies.

Countries like China that have pursued tight Covid-Zero policies by attempting to wipe out every infection, may eventually have to consider a looser stance. Others like the US and UK which have opened up despite a resurgence in the virus run the risk of wave after wave of infection.

Vaccines so far haven’t been the quick fix some had hoped for. Israel, among the most vaccinated countries in the world, has already started administering booster shots, amid evidence that the current immunizations aren’t offering the protection that was hoped.

The most powerful vaccines, including the mRNA shots from Pfizer Inc, BioNTech SE and Moderna Inc, would make it easier to get high levels of immunity since they are so effective. Yet breakthrough infections are possible with even these shots.

The benefits of other approaches, including those made by China’s vaccine manufacturers, AstraZeneca Plc and Johnson & Johnson, may offer even less protection.

Herd immunity is a real thing, protecting much of the world against viral threats from the measles to polio. Scientists credit it for helping eradicate smallpox. Having it as a goal likely helped the world embrace measures like wearing masks and social distancing. But it also created a false narrative.

Despite evidence that it will be difficult or impossible to reach herd immunity, many public health officials aren’t willing to give up on it. Governments worldwide are focusing on widening inoculation programs.