NHS doctor for his no-bullsh*t answers to Covid, testing and lockdown 2.0 questions

Back in April, Dr John du Parcq from St George’s Hospital in London answered some of our Coronavirus questions when none of us knew what the hell was going on in the world.

Six months on we’re still confused and anxious about our Government’s rules and restrictions, and whether this virus is EVER going to go away. So we got Dr JdP back for a second session.

Strap in for some hardcore science as he tackles the GLAMOUR team’s AW20 Covid Q&A.

What new things do we know about Covid that we didn’t know when you wrote your last piece?

We don’t know that much more about the virus itself – experts learnt what is it and how it behaves just before things started to go seriously wrong in the UK in the Spring. But we know more about how the virus affects humans, backed-up by the weight of evidence that can only come from large scale, population-based data.

They’re things we suspected anyway; for instance that children are very unlikely to get seriously ill, many people are asymptomatic with the infection and mortality is worse in certain adult groups (e.g. people with heart disease). The big change from back then is our ability to measure who has or has had the disease.

Why is testing such a giant clusterf*ck?

Great question. Testing’s a funny thing. What is the purpose of a test when the result is just a number or a positive/negative? What matters is that you have to know what you are going to DO with the result of that test. This applies not only on an individual basis, but also at a population level. That plan then dictates who you should test and when.
The bulk of testing has been passed over to a small number of large providers, working under the banner of the NHS but outsourced to non-NHS entities. Personally speaking it has upset me to see this happen as I know just how much passion, capability and experience there is in established NHS labs.

Science must be endlessly self-critical and it must be 100% open to criticism by others; that criticism is a foundation of scientific progress. So at the end of all of this I would ask that the decision to do things the way we did is opened up for review and critique from both inside the Public Health establishment and from those outside of it.

How accurate is the testing?

We can currently test for current infection “antigen testing” and previous infection “antibody testing’. Just like cars on the road there are many manufacturers of test kits, which claim to do different things with different accuracy.

The tests are specific; a positive result is a great indicator that you have or have had the infection. They are not entirely sensitive; a negative result doesn’t mean for sure that you don’t have it or haven’t had it.

For example, an antigen test should be undertaken within 5 days of the onset of Covid19 symptoms as we suspect that this is the time when antigen shedding will be at its highest. Furthermore, if you are only being tested after being symptomatic for 10 days, for example, you’ve probably spread the infection all over the place anyway so what’s the point in being tested for isolation purposes.

Antibody tests are usually more accurate further down the line from the point of infection.

Are pin prick antibody tests accurate at all?

Yes. Although the studies are small they indicate accuracy of >95%. In science terms this is really good.

The WHO has pioneered a collaboration of pharmaceutical companies, governments and charitable foundations to roll out a pin prick testing kit that will be made available in developing countries. It shows results in minutes, like a pregnancy test, and is probably >80% accurate.

The UK is developing a saliva test that hopes to give results within 90min. I can see this being useful in airports for example.

What is the scientific basis behind rule of six?

Great question. I can’t find any basis. This virus is spread by close human contact involving touch or airborne droplet infection. The more people come into contact with each other, and the longer and closer they are in contact for, the greater the risk of infection.

The rule of six seems to try to pick a sensible point on a sliding scale of risk, although why not ‘5’ or ‘7’ is beyond me.

Are the government *actually* following the science?

Yes, sort of. Our government, our society, takes its cues from science, religion, culture, tradition and the economy. To focus intently on one (e.g. road safety) would create a society potentially skewed against its many other facets.

We know we could save lives with a 10mph speed limit on our motorways, but the effects on society would be significant. Nobody can put a price on a life, but we all do that every day without really realising. Life is a compromise.

Science is taking a front seat in this process, as well it should. At times I personally worry that the scientists are being wheeled out when there is someone to blame for an unpopular decision, and hidden away when they could add meaningful (if uncomfortable) comment on a tricky situation. But I’m a scientist and I would say that.

Realistically when do you estimate a vaccine would be in circulation?

I think a vaccine will be available in the winter or Spring, although whether it will meet the rightly stringent licensing criteria of the UK’s excellent Medicines and Healthcare Regulatory Authority (MHRA) is uncertain.

The UK is a major player in biotechnology; we are really good at it. A UK vaccine will most likely be ready in the Spring and will probably be rolled out in a stepwise fashion according to perceived need.

How long, speculatively, would a second lockdown need to be to “break the circuit”?

Oh if this was as easy as turning off a light switch! If we went ‘all-in’ and really put the brakes on this country (no work, no shopping, no school, no dog walking), I reckon a lock down of 4-6 weeks would work wonders. But our society does not work like that. We would be curing the headache by cutting off the head.

I think that as soon as the first outbreak occurred, the onward transmission of this virus in the population was guaranteed. It was essentially endemic.

What’s the situation/atmosphere like for your colleagues on the front line?

I am a pathologist so I am not strictly ‘front line’. I think health professionals are concerned about the effects Covid will have through a winter, simply piling on extra pressure we might not be able to cope with. This is always a tough time for the NHS so we’re all a bit anxious.

In terms of autopsy we now know what to look for with the infection. The Royal College of Pathologists administrates a portal into which all autopsies undertaken on Covid+ patients can be uploaded. Across the medical world there has been a great deal of combined effort and sharing of thoughts and findings.

I hope we are now better at helping families when their loved ones are unwell, dying or have passed away. We have always been a very physical and permissive society, and the NHS reflects that. To restrict relatives’ access to patients is contrary to our core values and I hope we can find a way round the physical barriers that stop us from doing this.

As a diagnostic cancer pathologist I hope we do not place routine cancer and non-cancer medicine aside, like we did in the Spring. I understand it was a tough decision to make, delaying or cancelling operations and investigations. We have been picking up the pieces over the Summer and we probably haven’t really got back to normal yet. That’s probably my biggest worry.

Are you expecting a rise in deaths again (at the moment deaths are still low in comparison to cases)?

Yes. There will be many deaths over the Winter from Covid-19, although the number and rate of deaths will probably be slightly lower.

Why are we going into lockdown and damaging the economy to this extent when there aren’t many people dying?

I’m not sure it’s possible to answer this question. Obviously, we worry about people dying, and death should be avoided if at all possible. But it’s not just old people dying in care homes; that is a tired narrative. Covid kills young people too, not kids, but definitely people between 30-50 years old who might have other health issues going on. We have seen the effects of Covid infection in the placentas of children born to mothers with the infection.

On top of this is the effect of the Covid sickness on our society, on our healthcare and school systems. The volume of people becoming ill at once, much like a bad seasonal flu, could overwhelm our health system, causing knock-on effects which cause excess sickness and death in non-Covid corners such as stroke, heart disease, cancer and paediatrics. Similarly, how many of our schools could cope with the sickness of a large proportion of their teachers at once?

There is no redundancy or resilience in so many of our social structures that this virus had to be suppressed. We have essentially paid our way out of the problem and given ourselves hopefully enough time to create a vaccine. Death in society doesn’t actually cost that much in economic or social terms. Sickness most certainly does.

Is the virus getting weaker?

No, there is no evidence to suggest that SARS-CoV-2 is now any less pathogenic than it was in the Spring.

Is there any confirmation on long-term effects?

It is still too early to say. Some people suffer headaches, muscle pain, tiredness and coughing for longer than the majority of sufferers. This can persist for months. We do not know if there is documented long term, significant lung damage from Covid-19. The infection is characterised in a significant minority of patients by the development of acute respiratory distress syndrome (ARDS), often requiring ventilation.

ARDS has many other causes and we know by following up these patients that although they can show chronic scarring changes in their lungs on CT scanning, patients are most often asymptomatic. The outlook is good then, but this is definitely something medics will be keeping an eye on.

Can people catch it more than once and if so, how does herd immunity work?

Great question – this is something I’ve been watching closely. Despite all the scientific work and focus in the area over the Summer, there was not really a documented, confirmed case of re-infection in the published literature.

There is now, with published cases in Hong Kong and Nevada supported by good science. In one case the second infection was very mild, in the other it was quite severe so we’re stuck for an answer for the time being.

Sure, we do not know what degree of immunity is held by people who have had the virus, or if the degree of immunity is relative to having a positive antibody test. A family member of mine had a positive antigen test followed by a negative antibody test. She has not had the infection again despite probably being exposed to the virus.

What are T cells?

T cells are a subset of lymphocytes, a key part of our immune system. They work with B-lymphocytes to coordinate our immune response. B-cells produce antibodies; this is what the antibody test looks for. T-cells can act as ‘killer’ cells, terminating our own body cells infected with virus. They also act as helper cells, directing the immune response to where it is needed. There is some evidence that Covid infection induces T-cell immunity, and evidence from previous outbreaks (SARS and MERS) suggests T-cell immunity may be very long lived.

What new symptoms have been detected; for instance, upset stomach and diarrhoea?

There have been no new symptoms or pattern of symptoms that build on what we already know. Whilst headache, diarrhoea and fever may be seen in many illnesses and are not specific, it’s the loss of taste and smell (without an obvious cold or runny nose0 that would very likely point to a Covid infection.

Should we stay away from vulnerable people just in case?

Right now, I am staying away from vulnerable people. Infection rates are on the rise in my part of the world, and doing my job probably puts me (and them) at slightly higher risk. My parents are well in themselves but have some risk factors. I would find it hard to cope with the thought that if anything happened to my parents, it might be my fault. I think my parents think I’m overreacting, but they’re OK with it. I’m also sure they are cheating and doing things I tell them not to do without telling me!

What is more effective for reducing spread: wearing a mask or hand-sanitising?

Each is most effective when used in combination. Sounds boring, but it’s true.


It will never end. This virus is with us forever. It is tantalising to think that for the briefest of moments we had the ability to stop a virus in its tracks, to render it extinct. But we missed our shot and now it’s part of our ecosystem. Our kids and their kids will come to treat it more like a bad seasonal flu. We will have our vaccine every year. Maybe we’ll all wear masks on the Tube forever, I don’t know. But the severity of the illness, the pandemic mentality and social upheaval will dissipate over time. It will become like all the other worries in our lives; ever present, surprising us every so often, but no longer hitting the front pages.

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