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Second wave of Covid-19 cases possible if lockdown lifted too soon – Dr Neil Martinson
The lockdown can seem endless, now that South Africa is past the halfway mark, especially when people are not even allowed to go out for exercise and where alcohol and cigarettes are prohibited. But right now; things are looking up for South Africa. The number of new cases and fatalities has plateaued and a study by Dr Gonzalo Otazu from the New York Institute of Technology has found that there is a correlation between countries that require citizens to get the Bacillus Calmette–Guérin (BCG) vaccine to prevent TB and lower death rates from the coronavirus. This is a vaccine that the majority of South Africans receive as babies. Another plus for South Africa is its vast testing infrastructure due to the high number of HIV/Aids cases in the country, which the deputy director of the Reproductive Health Institute at Wits, Francois Venter has described as unprecedented in the world to ABC. So, it would be easy to rejoice and think we may be close to conquering the Covid-19 beast. In an interview with Biznews founder Alec Hogg for the Inside Covid-19 podcast, the deputy executive director of the Perinatal HIV Research Unit at Baragwanath Hospital, Dr. Neil Martinson had a word of caution and said that a second wave of coronavirus infections is possible if containment measures are lifted too soon. – Linda van Tilburg
A warm welcome to Neil Martinson who is very close to the subject that we’ve been picking up on the BCG or the Bacillus Calmette–Guérin vaccine. Please take us through exactly what it is that you guys focus on.
My focus is on TB research and as you know, TB is the biggest killer of people in South Africa at the moment, primarily because it’s linked to HIV. The BCG is a vaccine against TB – that everyone in South Africa probably has had – and a lot of us older people have probably had two jabs when we were younger, now currently it’s given to all children at the time of birth, except for kids who are infected with HIV.
And the PHRU – of which you are the deputy executive director – where are you based?
We’re based in Soweto at the Chris Hani Baragwanath Hospital and we have another satellite site in at the Tshepong Hospital in Klerksdorp as well as some other smaller sites in the Free State and in Limpopo Province.
So you’re on site as it were with the research that you do and there are presumably clinicians as well?
Yes we do our work at the PHRU – clinical research – directed at mitigating the impacts of HIV and tuberculosis in southern Africa.
Tell us about this BCG vaccine because there is very promising information coming from the New York Institute of Technology’s College of Osteopathic Medicine, saying that those who’ve been vaccinated as babies with it, which as you’ve just explained South Africans have been, might have a better defense system against Covid-19
There has been some interesting research, The problem with BCG is that it’s not a very good vaccine in terms of preventing tuberculosis. Although we have a universal vaccination in South Africa – for many decades – tuberculosis is still an incredible public health problem. This vaccine clearly is not making a major impact – on the TB epidemic particularly – as it’s been exacerbated by HIV, however several clinical trials of BCG have shown an unexpected non-specific benefit on mortality in infants. This was the one signal that people are trying to hang Covid-19 on, that kids who received the BCG had lower infectious disease mortality than kids who didn’t receive the BCG. Even though the protective effects against TB weren’t that marked, there was this side effect of BCG. So I guess this is what spurred this paper that you’re alluding to which looked at rates of BCG and tried to relate the rates of BCG in each country, to deaths due to Covid-19 as well as to the overall population rates of Covid-19. Essentially, what they’re finding is that countries with lower coverage of BCG have higher Covid-19 rates and higher mortality rates than those countries with higher rates of BCG. That’s really what the results of that study are showing.
From outside – just looking at the numbers – it’s an irresistible argument to say that the United States, Spain and Italy, who haven’t had BCG vaccinations have got a very high mortality rate, whereas other countries do not. Are we clutching at some straws here?
I’d say we’re clutching at straws, but what I would caution people about is to take what epidemiologists call ecological evidence – taking population level figures and drawing up some correlation between population level figures – and then drawing a conclusion that may be flawed. There might be other things at play here. If they had to repeat the same study in 4 months time, they may find very different figures. South Africa clearly is at the beginning of its Covid-19 epidemic, we could still reach for the stars like Italy, Spain and America have been. The second thing is that the coverage of testing – as you probably have seen and heard experts say – the more you test the lower your death rates. If you test people who get admitted to hospital with symptoms of Covid-19, you’re going to have a very high death rate. If you test a large number of people – who may or may not have symptoms – the death rate (even though the overall death rate might be exactly the same) will be reflected much lower than a country that only tests people who have symptoms, those walking into hospital. For those two primary reasons, I would be a bit cautious about jumping to an immediate conclusion saying this is something that we must start vaccinating people for. There are two trials that I’m aware of – either being planned or they’ve started – one of them in Stellenbosch and another one in the Netherlands, but it’s very difficult to be able to say from that sort of ecological data, that we should be doing something more with BCG than we are already. It might be – if there is a protection – that a second vaccination may add protection, but it might also be that if you gave a second vaccination shortly after you were exposed to Covid-19, it might not have an effect or maybe even exacerbate your chance of being infected with Covid-19. The vaccine world has been fraught with some interesting surprises that have been somewhat counter-intuitive, so I think that doing well conducted clinical trials is appropriate.
Neil, why is it that South Africa has had this experience of 20% even 30% growth initially and then flatlined in the last few days, very low single figure increases in the infections. Is this a consequence of what you spoke about a moment ago of just not that many people being tested?
The rate of positives to those tested is extremely good. When last I looked we had tested approximately 40,000 people to generate a 1,300 cases or thereabout, so the testing has been appropriate for the scale of the epidemic. There has been a recent announcement that testing is going to massively increase (certainly the testing sites where people can walk in and be tested) will be lowered as the epidemic progresses. To flatten the curve – which we’re trying to do – it appears that the initial announcement by the president and the stopping of flights from Europe, have possibly both contributed to the reduction of community transmission. Although most of the initial cases were from Italy and other parts of Europe, the real killer – for South Africa – is when there’s widespread community transmission. The ability of the Health Services to respond to widespread community transmission – at the time when we had our first 5 or 10 cases – was really limited. Both the lockdown, the effects of which we are probably starting to see right now in the reduced transmission as well as the reduction in European tourists and travellers, together with the initial restrictions on movement and restrictions on football games and restrictions on other mass gatherings I think are now starting to bear fruit.
But what happens when we come out of lockdown, presumably a second wave is possible?
Yes. You’ll have noticed that in Italy, Spain and the US, these lockdowns have been extended. I suspect that unless there’s a incredible reduction in the daily increase of new cases, our lockdown will either be extended or will be extended with slightly less restrictions on movement or might be targeted to certain areas identified as hotspots for transmission. I don’t see that 3 weeks of lockdown will be sufficient to curb the epidemic to such an extent that we can leave our houses and go back to normality.
There’s been a lot of preparation by the medical practitioners around the country, have we had enough time to get ready for it?
We probably would never have enough time, but the initial detection of cases – and the racking up of the government’s response when the president first announced the lockdown – really galvanised both the public and the private sectors to start taking this very seriously. Certainly, there has been a combined response from both public and private sectors to rally all the resources they can, to provide more PPE protective equipment for health personnel, to get more testing sites and to ensure that the economic impact of this terrible epidemic is not felt too much. Although I suspect it’s going to have a dramatic effect.
Something which observers are concerned about is the high HIV/Aids incidents in South Africa, presumably that would cause a threat to a lot of people – millions of people – with immune deficiency. Do you have any thoughts on that? Is this threat being exaggerated or is it very real?
It is unknown. The vast majority of people who are HIV infected in South Africa are now taking antiretroviral therapy, which should provide some form of protection. The problem is in countries where the epidemic has really taken hold, HIV prevalence is very low. The experience with people who are co infected with HIV and Covid is limited. South Africa really provides a unique opportunity to ascertain what the impact will be. I’m sure that the 7 million people in South Africa who are HIV infected, weighed heavily on the president and the Minister of Health’s minds when they were making this decision to have a lockdown. The intuition of most medical people is that HIV is likely to have a deleterious effect on the progression of the disease if someone does become infected.
Is the Baragwanath Hospital still the biggest hospital in the southern hemisphere?
Have you seen increases in Covid-19 cases?
There have been several cases. I am not a clinician – in the true sense of seeing patients as they get admitted into Bara – but I have heard that they have had several positive patients. I don’t think that they’ve had anyone who has been admitted to ICU yet. but I might be wrong.
But they’re not being overwhelmed certainly not at the moment?
No and I think this lockdown has given them the opportunity to start increasing the number of beds and to gather the resources like ventilators and to ensure that their isolation wards are separate from the general run of the mill patient and to prepare properly for the impending flood of patients. If this lockdown doesn’t work or if the lockdown merely delays a subsequent massive increase in the number of patients with infection.
Dr Neil Martinson is the deputy executive director of PHRU.
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