Tag: public health

Attaining Herd Immunity for COVID Now Unlikely

Image by Quicknews

In an article published in the South African Medical Journal, Shabir Madhi, Professor of Vaccinology at Wits, argues that COVID variants have made the initial goal of attaining herd immunity no longer feasible, even for well-resourced countries. However, vaccine protection against severe COVID seems a more realistic path to normalcy.

In low and middle income countries (LMICs), the official COVID case estimates are likely grossly underestimated, Prof Madhi writes, due to a lack of testing coverage. Even in South Africa, the true number of COVID cases is likely in the region of 10 times the 2.39 million recorded through testing. The true number of COVID-related deaths in India is also estimated as 3.4–3.9 million, again 10 times the official count, and in South Africa it is likely three times the official  figure of 70 388 in July 2021.

While New Zealand researchers have suggested that COVID eradication is feasible, it is likely a very long term goal if at all attainable. The herd immunity goal can be considered with the equation (p1 = 1 – 1/R0), where p1 is the proportion of immune individuals who will also no longer transmit the virus, and R0 is the reproduction rate, ie the number of susceptible individuals a single infected person can further infect. However, this ignores key aspects of the virus.

The problem is that the proportion of people that would need to be immunised to achieve herd immunity was initially calculated at 67%, based on an assumed R0 of 3, derived from the Wuhan strain’s R0 of 2.5 to 4. However, the Delta variant has an R0 of 6, meaning that to reach herd immunity, 84% of the population would need to be vaccinated. In South Africa, this would be 100% of the population aged over 12.

The emergence of SARS-CoV-2 variants, especially the Beta variant with the E484K mutation, showed that existing vaccine protection, including the Pfizer variant, can be degraded to an extent.

Studies have strongly suggested that neutralising and antibody titers are associated with mild to moderate COVID protection, while protection from severe COVID may be mediated by T-cell immunity.

Real world data showed that in Israel, with a world best immunisation of 61.6% using the Pfizer vaccine which produces the greatest antibody response, herd immunity appeared to be successful until an outbreak of the more transmissible Delta variant combined with waning vaccine effectiveness. 

However, in the UK, excess death data showed that, even with a resurgence of cases caused by the Delta variant, there was a significant decoupling of deaths from cases. This points to the effectiveness of vaccines in preventing severe illness, as opposed to reaching herd immunity.

Vaccine rollouts have therefore not interrupted COVID transmission. Prof Madhi concludes that, based on an estimated R0 of 6 for the Delta variant, “it is unlikely that any country could have a sustainable strategy for durable high level of protection against infection by the delta variant. Mutations of the SARS-CoV-2 genome are likely to continue resulting in enhanced transmissibility, infectiousness and resistance to neutralising activity.”

He observes that the “UK approach seemingly concedes that the goal of herd immunity, even in a highly resourced setting, is unattainable.”

He adds that aspiring to reach herd immunity by wealthy countries comes at the cost of exacerbating vaccine inequality, which he says “is immoral.”
Antibody dynamics modelling suggests that a booster would be required every 2–3 years to protect against severe COVID, and every 6–9 months to protect against moderate disease. This is a challenging goal, and likely unattainable for most LMICs, especially given the slow rate of vaccination in those settings.

Source: South African Medical Journal

A Look Back at Mkhize’s Tenure as Health Minister

Image by Hush Naidoo from Unsplash
Image by Hush Naidoo from Unsplash

With Dr Joseph Phaahla being promoted from his position as Deputy Health Minister to replace the embattle, Dr Zweli Mkhize, Spotlight reviews Dr Mkhize’s tenure, writing that the very reason he was brought in to that post — to roll out National Health Insurance — would likely suffer a considerable setback as a result of his exit.

His appointment as South Africa’s Minister of Health in May 2019 came as a surprise for some. As one of the ANC’s top officials, the health portfolio seemed a meagre choice in the pre-COVID days.

However, Mkhize’s seniority signalled that health was being given high priority in the new administration. Theoretically, his greater political clout meant he would have a better chance of bringing much-needed reforms to provincial healthcare systems. Spotlight were also “cautiously hopeful that Mkhize’s firmer hand would help better organise and direct the National Health Department and the various national health entities.”

A string of procurement scandals during his time as KwaZulu-Natal’s Premier was cause for concern but was not direct evidence that he was corrupt.

The Digital Vibes scandal had the side effect of making Mkhize anathema to the very project he was originally brought in for, implementing National Health Insurance.

Even with Mkhize gone, the ANC will have a hard time convincing the public that we will not see more such looting once NHI is implemented. There has, after all, been little willingness from ANC members in Parliament to engage seriously with people’s concerns about the proposed NHI structure and governance arrangements set out in the NHI Bill.

Mkhize tackled COVID from a scientific standpoint, which is fortunate for the nation considering the anti-scientific stance of the former Minister of Health Dr Manto Tshabalala-Msimang. However, the decision not to use AstraZeneca vaccines remains contentious. Meanwhile, a purge of scientists, starting with Professor Glenda Gray, let Mkhize surround himself with allies, according to Spotlight.

However, entering the third wave with vaccinations lagging so far behind was a governance disaster possibly even worse than the Digital Vibes scandal.

From an outside perspective, the past two years have not seen great progress in the department, despite some competent individuals, with infighting, under-capacity and most seriously, poor management. The procurement department

Source: Spotlight

WHO Calls for COVID Booster Pause to Let World Vaccinate

The head  of the World Health Organization (WHO) on Wednesday called for a moratorium on COVID vaccine boosters until “at least the end of September” to enable the world’s most vulnerable people to be inoculated.

“I understand the concern of all Governments to protect their people from the Delta variant, but we cannot accept countries that have already used most of the global supply of vaccines using even more of it, while the world’s most vulnerable people remain unprotected”, said Tedros Adhanom Gebreyesus, WHO head.

Speaking during his weekly press conference, Tedros recalled that in May he had asked for international support to promote global vaccinations with the goal of enabling a minimum of 10 percent of each country’s population to be vaccinated by the end of September.  

With the time already half gone, he lamented the lack of progress towards that goal, and even less towards the target of 30 percent vaccinated by year end.

Widening inequality
So far, more than four billion COVID vaccine doses had been administered around the globe, 80 percent of them in high- and middle-income countries – even though less than half of the world’s population live there, the WHO chief said.

As of May, high-income countries had administered about 50 doses for every 100 people, a figure that has since almost doubled, while supply shortages in low-income countries meant only 1.5 doses for every 100.

“Still, some rich countries are considering booster doses even though there are hundreds of millions of people waiting to have access to a first dose”, stressed Tedros, urging that most of those vaccines instead go to low-income countries.

The WHO has insisted global vaccination requires cooperation by all, “especially the handful of countries and companies that control the global supply of vaccines”.

Tedros said that the G20 nations have a vital role to play as its members are the largest producers, consumers, and donors of COVID vaccines.

“It’s no understatement to say that the course of the pandemic depends on the leadership of the G20 countries”, he said, adding, that one month from now, the G20 health ministers will meet, ahead of the October summit and calling on them to “make concrete commitments to support WHO’s global vaccination targets. We call on vaccine producers to prioritise COVAX“.

Tedros also called on leaders and influential personalities, as well as every individual and community to support the moratorium on booster doses.

Booster’s immune benefit questionable
Meanwhile, Dr Jarbas Barbosa, deputy director of the Pan American Health Organization (PAHO) emphasized that so far there is no evidence that a booster dose adds immune benefits to people who already have the full vaccination course.

Source: UN News

Human Rights Commission Inundated with Complaints of Pressure to Vaccinate

Photo by Bill Oxford on Unsplash

The South African Human Rights Commission (SAHRC) said that it had been inundated with complaints from people who claimed they had been pressured to get a COVID vaccination. These included tenants being threatened with eviction if they did not vaccinate.

Employees and tenants were not the only ones coming forward; companies had also approached the commission for guidance and clarification. The situation is something of a grey area for employers, according to the Department of Labour’s director-general Thobile Lamati.

“Can the employer then force the employees to take the vaccine? This is a very difficult question because we have different work places and different situations,” he said, adding that a worker could not be compelled to take a vaccine without the risks being explained to them.

On Friday morning, acting Health Minister Mmamaloko Kubayi-Ngubane reiterated that vaccination was purely voluntary and confirmed that employers were not allowed to force workers to get the jab.

Nevertheless, the government is encouraging all eligible South Africans to achieve herd immunity, and exit the cycle of waves and economically crippling lockdowns. However, inoculation has not been mandatory, with a target of around two-thirds of the population vaccinated. In a statement, President Cyril Ramaphosa said that only one in ten South Africans now believed that COVID vaccines were not safe.

The commission’s Buang Jones said they would also be examining the reasons given by some people refusing to receive vaccines.

“The reasons may range from medical, religious or other constitutional accounts. But complainants will be requested to take us through their reasoning and the team will be offering advice to those who have complained to the commission.”

Jones said that companies also voiced concerns about the negative impact that COVID had had on their finances.

“That they would like staff to be at work and ensure that the company functions optimally. Their concern is there will be increases in sick leave taken and it will affect production. They are also concerned about the rights of other employees to have chosen to take the vaccine.”

Source: Eyewitness News

Nine in Ten Hypertension Cases Need More Treatment

Image by Hush Naidoo from Unsplash
Image by Hush Naidoo from Unsplash

A series of studies has shown that in most cases, hypertension is not being adequately treated.

Hypertension is the leading treatable cause of illness and death worldwide. More than a billion people are hypertensive, defined as having diastolic blood pressure (BP) with 140mmHg or higher, or diastolic blood pressure (DBP) 90 mmHg or higher. Fewer than half of people with hypertension are aware of their condition.

This condition increases the risk of several dangerous illnesses, such as myocardial infarction (MI) and stroke, and of dying prematurely. For some patient categories, the most advantageous BP levels in terms of avoiding MI and stroke are uncertain.

In one of the studies in his thesis at Sahlgrenska Academy, University of Gothenburg, specialist doctor Johan-Emil Bager investigated the link between BP levels and the risk of MI or stroke in 5041 older patients.with hypertension but no history of heart attacks or strokes.
Risk for MI or stroke was found to be some 40 percent lower for the patients with systolic blood pressure (SBP) below 130 mmHg, compared with those in the SBP 130–139 range. In the latter group, 5.2 percent of the patients experienced a heart attack or stroke during the follow-up period, compared with 3.4 percent of those in the lower SBP group.

This pattern was repeated in another study, which investigated the risk of haemorrhagic stroke at different levels of BP in 3972 patients with atrial fibrillation (AF). These patients were receiving treatment with blood-thinning drugs, such as Warfarin or Eliquis.

The study showed that patients with SBP ranging from 140 to 179 mmHg had a haemorrhagic stroke risk roughly double that of patients with SBP of 130–139 mmHg. In the patient group with higher SBP, 1.4 percent suffered a hemorrhagic stroke during the follow-up period, compared with 0.7 percent of patients in the group with lower SBP.

A separate study with data on 259 753 patients also demonstrated insufficiency of hypertension treatment. Nine out of ten patients had either insufficient BP control or high blood lipids (cholesterol), or were smokers.

Johan-Emil Bager at the University of Gothenburg, said: “This means that an overwhelming majority of the patients with high blood pressure are exposed to at least one important, modifiable risk factor for cardiovascular disease and premature death.”

He concluded that an unnecessarily high number of people in Sweden suffer MI or stroke, or die prematurely, because of insufficiently treated hypertension.

“Health professionals and patients with hypertension alike need to aim higher when it comes to treating high blood pressure. The vast majority of patients with hypertension could reduce their MI and stroke risk by lowering their BP and blood lipids with more drugs, or through lifestyle changes.”

Source: University of Gothenburg

Untreated Sewage is a Driver of Antibiotic Resistance

Photo by Jordan Opel on Unsplash
Photo by Jordan Opel on Unsplash

Contamination of urban lakes, rivers and surface water by human waste is creating pools of ‘superbugs’ in Low- and Middle-Income Countries (LMIC), according to new research. However, improving access to clean water, sanitation and sewerage infrastructure could help to improve public health.

For the study, researchers studied bodies of water in urban and rural sites in three areas of Bangladesh: Mymensingh, Shariatpur and Dhaka. In comparison to rural settings, they detected more antibiotic resistant faecal coliforms in urban surface water , consistent with reports of such bacteria in rivers across Asia. Their findings were published in mSystems.

Lead author Willem van Schaik, Professor of Microbiology and Infection at the University of Birmingham, commented: “The rivers and lakes of Dhaka are surrounded by highly-populated slums in which human waste is directly released into the water. The presence of human gut bacteria links to high levels of antibiotic resistance genes, suggesting that such contamination is driving the presence of these ‘superbugs’ in surface water.

“Interventions aimed at improving access to clean water, sanitation and sewerage infrastructure may thus be important to reduce the risk of antimicrobial resistance spreading in Bangladesh and other LMICs. While levels of antibiotic resistance genes are considerably lower in rural than in urban settings, we found that antibiotics are commonly used in fish farming and further policies need to be developed to reduce their use.”

Infections from antibiotic-resistant bacteria are on the rise globally, but the clinical issues posed by these bacteria are particularly alarming in LMICs, with significant morbidity and mortality. As in other LMICs, multidrug-resistant E. coli has a relatively high prevalence in healthy humans in Bangladesh.

With a population of around 16 million people, Dhaka’s population density ranks among the highest of any megacity, but less than 20% of its households have a sewerage connection.

Urban surface waters in Bangladesh are particularly rich in antibiotic resistance genes, the researchers discovered, with a higher number of them associated with plasmids — vehicles of genetic exchange among bacteria — indicating that they are more likely to spread through the population.

Antibiotic-resistant bacteria that colonise the human gut can be passed into rivers, lakes and coastal areas through the release of untreated wastewater, the overflow of pit latrines during monsoon season or by practices such as open defecation.

Such contaminated environments are often used for bathing, for the washing of clothes and food utensils, thereby risking human gut colonisation by antibiotic-resistant bacteria.

The researchers from the University of Birmingham and the International Centre for Diarrhoeal Disease Research, Bangladesh called for further research to quantify the drivers of antibiotic resistance in surface waters in Bangladesh.

Source: University of Birmingham

Journal information: McInnes, R.S., et al. (2021) Metagenome-Wide Analysis of Rural and Urban Surface Waters and Sediments in Bangladesh Identifies Human Waste as a Driver of Antibiotic Resistance. mSystems. doi.org/10.1128/mSystems.00137-21.

As Gauteng Weathers Third Wave, Western Cape Readies its Defences

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While COVID infection rates in Gauteng remain high, Western Cape is now firmly in a third wave, with an average of 1969 new cases a day. The healthcare system there has been monitoring the situation and preparing for the expected surge in cases.

“We are in a steep third wave, driven by the Delta variant and urge everyone to adhere strictly to protective behaviours, as a key drive to contain it. We anticipate that the third wave could be as high as the second wave. We await revised modelling from the SACMC to re-calibrate our response,” said head of health Dr Keith Cloete. Data on cases, healthcare capacity and details of the Western Cape’s responses were made available on the SA Coronavirus Portal.

In the Western Cape, the reproductive number has been over one for the past two months and is currently sitting at approximately 1.2, meaning an acceleration of new cases. The test positivity rate is at about 32%.

The public and private sector are using around two-thirds of the oxygen production capacity of Afrox’s plant. The level 4 restrictions with their accompanying alcohol ban saw a significant drop in week-on-week trauma presentations (~25%) and weekend trauma burden (~33% drop). This comes even with the context typical end of month increase as well as expected remaining alcohol stock, demonstrating the ban’s effectiveness.

The modelling referred to by Dr Cloete currently shows a high of ~500 daily admissions by 17 July, however an updated model is awaited. Public sector COVID bed capacity is being increased by converting beds and opening field hospitals, with a planned capacity of 2300 beds.

About 48.5% and 10.4% of the Western Cape population aged 60+ and 50-59 respectively have been vaccinated so far. Meanwhile, in a media briefing on Friday, Acting Health Minister Mmamoloko Kubayi-Ngubane announced that COVID vaccine registration for South Africans between the ages of 35-49 will open on July 15, with vaccinations for this age group planned to commence on August 1.

South Africa Mulls AstraZeneca Again in Light of Delta Protection

Photo by Mika Baumeister on Unsplash

Four months after selling off one million AstraZeneca vaccine doses, South Africa is considering buying more of them to contain the spread of the Delta variant.

The Delta variant is much more transmissible than previous strains, including the beta variant. However, the government presented data on 26 June showing a 70% efficacy against it with the AstraZeneca vaccine. The vaccine, which of June 2021 comprises over 90% of all doses supplied through COVAX globally, will have a significant impact as the Delta variants spread.

The government may approach the Serum Institute of India for the shots, deputy health minister Joe Phaahla told lawmakers on Wednesday.
This would add to supplies as the health regulator considers approving Russia’s Sputnik V and China’s Sinovac inoculations, he said, adding that he hoped to secure these doses from India’s Serum Institute.

In March, also facing expiry on the doses, the government sold off its doses to the African Union after research showed the then dominant Beta variant was resistant.

In February, University of the Witwatersrand Professor of Vaccinology Shabir Madhi said the AstraZeneca vaccine had a roughly 20% efficacy in preventing mild disease from the Beta variant.

“We don’t want to go back to the original argument of whether its limited efficacy on the Beta variant was correct, to dispose of it, to sell it to other countries,” Phaahla said. “With the current information that it is quite efficacious when it comes to the Delta, it is already registered.”

A study by the University of Oxford,demonstrates that AstraZeneca’s COVID vaccine, will provide protection against the Delta and Kappa variants; formerly the ‘Indian’ variants. The study investigated the ability of monoclonal antibodies from recovered or vaccinated people to neutralise the Delta and Kappa variants. 

Neutralisation against the Delta and Kappa variants was comparable with that seen against the Alpha and Gamma variants, with no evidence of widespread antibody escape as seen with the Beta variant. These results indicate that the vaccines could be effective in real-world settings. The Phase III COV002 trial in the UK showed vaccine efficacy of 70.4% at preventing symptomatic COVID against the Alpha variant, when measured more than 14 days after a second dose.

Furthermore, a recent analysis by Public Health England showed early evidence of real-world data that two doses of AstraZeneca’s COVID vaccine are effective against the Delta variant, with similar levels of protection achieved as those seen against the Alpha variant.

Sources: BusinessTechAstraZeneca

Positivity Rate at 25% as Lockdown Upgrades Expected

President Cyril Ramaphosa is expected to meet with the National Coronavirus Command Council (NCCC) to discuss the government’s response to the third COVID wave, which includes the possibility of new restrictions. 

Several bodies have strongly urged upgrading to a harder lockdown, including the South African Medical Association, the Gauteng Provincial Government, medical professionals, and now the Ministerial Advisory Committee on Covid-19.

Earlier this week Ramaphosa indicated that the government will have to increase its COVID containmant measure – especially in Gauteng province. He noted that the country’s first hard lockdown in March 2020, one of the strictest in the world, did help cut infection rates at the start of the pandemic.

South Africa recorded 17 493 new cases, a new daily high for the third wave, of which 10 806 were in Gauteng. Case positivity rate increased to 24.92%. A report released on Wednesday by the South African Medical Research Council showed that 1349 excess deaths in Gauteng for the week ending 13 June, of which 431 were due to COVID/

Warnings and failure to act

In an interview with The Money Show with Bruce Whitfield this Monday, Netcare CEO Richard Friedland had warned that the numbers of Covid-19 patients “are overwhelming facilities at the moment”.

Since Wednesday last week, Gauteng’s hospitals had been battling with a “mass casualty situation” , not unlike the aftermath of a train accident, or the collapse of a sports stadium, with “injuries on a massive scale”. But, with COVID, he said, the crisis is not over in a couple of hours, but remains ongoing.

With no evidence of a peak in case numbers, Friedland said that, “I’m afraid that these numbers are demonstrating that [without] a Level 5 lockdown in Gauteng, we may not see the end of this surge for some time.”

Professor Koleka Mlisana, co-chairperson of the Ministerial Advisory Committee on Covid-19, says that tighter restrictions are likely needed to help curb infections.

Prof Mlisana said that the other major crisis is making sure that there are sufficient hospital beds in Gauteng. This includes additional facilities, staffing members and beds to ensure the system is not overwhelmed, she said.

Prof Mlisana said that this was down to a lack of preparation by the government, despite warnings from the advisory committees. 

Source: BusinessTech

India Tests Out Drones for Medical Deliveries

Photo by Thomas Bjornstad on Unsplash

An aviation firm has carried out the first tests in India of drone deliveries at long ranges, in a step towards one day delivering medicines as well as COVID vaccines to remote areas.

India, with a population of 1.3 billion people spread across some 3.2 million square kilometres is the world’s seventh-largest country by land mass. Experts say that widespread use of drones could be a game-changer for medical services in the South Asian nation’s hard-to-reach rural areas with often poor roads and lack of healthcare infrastructure.

Drones are a cost-effective alternative to road transport in difficult terrains. They can be used in the transport of blood from the blood bank to the place of surgery and that of specimens from hard-to-reach areas to the labs in nearby towns. They can deliver essential medicines like anti-venom for snake bite and dog bite and prevent deaths.

Throttle Aerospace Systems is among 20 organisations granted permits by the government since May to conduct experimental flights beyond the current limit of 450 metres.

Two drones were tested in the southern state of Karnataka: one that can carry up to one kilogramme for 20 kilometres for nearly an hour, and another that can lift two kilogrammes for 15 kilometres.

“Medicines was the payload here and… 2.5 kilometres were covered in seven minutes and it delivered the medicines at the designated point and the drone returned,” Throttle’s co-founder, Sebastian Anto, told AFP at the test site.

This month the Indian government also invited bids from drone operators to help set up a pilot project for the delivering of medical supplies as it seeks to bolster its flagging COVID vaccination drive.

Samiran Panda,  epidemiology chief of the Indian Council of Medical Research, told The Hindu daily newspaper that the technology could help innoculate priority groups in hard-to-reach places.

“We need smart vaccination instead of mass vaccination to stem an epidemic,” Panda told the newspaper last week.

However, India lags behind many other nations when it comes to drones both in terms of their uses and the regulatory framework.Under current regulations, they have to be flown in full view, or within 450 metres, of their operators on the ground.

In Germany, it is reported that researchers are testing drone prototypes that can track down disaster victims by their screams. In Australia, drones using artificial intelligence algorithms are being used to spot crocodiles and count koalas in rugged terrain.

“Drone technology would have a huge impact in those areas where emergency medicines and vaccines could be supplied,” co-founder of lobby group the Drone Federation of India, Vipul Singh, told AFP.

“Where it takes a few hours to travel 20-30 kilometres by road, whereas a drone can actually travel that distance in 10 to 15 minutes,” said Singh, also the co-founder of Bangalore-based Aarav Unmanned Systems.

Source: Medical Xpress