Coronavirus: 'This is no time to lower our guard' says Cambridge expert


23-09-2020
Dr Mark Slack

"The virus is still very much with us and this is no time to lower our guard. We need to be more vigilant than ever about social distancing and hand hygiene," says Dr Mark Slack, Chief Medical Officer and Co-Founder of CMR Surgical. 

Writing here in his capacity as a medical doctor, he gives an expert view on the pandemic and the measures being taken to contain it:

We live in unprecedented times facing factual uncertainty on a daily basis. The Coronavirus pandemic has torn through the entire world, creating health and economic chaos in its wake. Even seasoned virologists and public health experts have been caught off balance.

Sadly this is not the first pandemic to strike the world nor will it be the last. Because of global travel and mobility this one has moved with an unprecedented speed, disrupting all before it.

The medical community has also responded with speed and has made major inroads into the management of the disease. If you had had severe COVID in March and required admission to the ITU requiring ventilation you would have faced a 50% mortality. In the same circumstance today, you will have a mortality (depending on age, weight and co-morbidities) of about 10%.

When the pandemic broke, we saw a flurry of activity to build ventilators to manage the shortage. Management of these patients has progressed so fast that the majority of patients no longer require ventilation but are better managed on high flow nasal oxygen – the Prime Minister being one of the first to benefit from this change. The widespread use of one of the oldest ITU drugs known to the medical profession (Dexamethazone - nothing new here), the addition of the antiviral Remsdesivir® and most importantly the early deployment of anticoagulants (oral in the community and intravenous in ITU) have decimated the mortality figures.

We now know that the disease has a strong pro-coagulant nature and that the resulting arterial and venous thromboses (clots) are responsible for the devastating pulmonary consequences. The clots are also responsible for renal and hepatic dysfunction and may have a role in cerebral (brain) dysfunction. If a patient gets COVID and is not showing signs of recovery by day 5/6 it is now agreed that it is time to start active intervention. In the early days there was a delay to active intervention which allowed the thrombotic consequences to progress much more widely. It is also the thrombotic complications responsible for the post infection prolonged illness experienced by many sufferers. This latest scenario highlights the need to take this infection seriously and not be glib about catching it.

The disease is mostly a minor one in young healthy children and adults. It certainly targets the obese, the elderly and those with co-morbidities. This part of the community still needs to shield and practise caution, as do healthy individuals who have contact with those at risk.

Vaccine development

The medical community has never seen anything like the rush to develop a vaccine. Having previously neglected vaccine development (not enough profit), multiple companies have rushed headlong into the race and are making incredible progress. The previous record for vaccine development was five years (Ebola) so the fact that some vaccines are entering Phase III trials (widespread randomized human clinical trials) after six months is unprecedented. Unfortunately, this has taken on a political hue and could result in premature releasee of vaccines with devastating consequences.

Some vaccines like the Oxford/AstraZeneca trial are showing great promise but considerable risks remain in this arena. Vaccines are capable of a phenomenon called Antibody dependent enhancement (ADE) which is where the vaccine is not protective enough to prevent the disease but instead allows the virus to enter the body more easily and worsen the disease the vaccine is supposed to protect against. Only properly conducted (with the correct timelines) trials will identify this. A prematurely released vaccine could risk extending the pandemic by months or years.

There is also considerable lay interest in the concept of a less virulent mutated version of the virus. This is largely fuelled by the observation that people seem less likely to die than early in the pandemic. The crude case fatality rate is about 1% compared with 18% in April. Partly the reason could be the improvements in acute care and also because the most susceptible succumbed first. It could also be that in some geographies (India and South Africa) the lower mortality rates could be linked to the large number of the population under the age of 40. The University of Singapore has claimed that a mutated version (D614G) is making the illness less deadly but this is disputed by many. The reduction in deaths may also be due to social distancing reducing the viral load when people are infected, allowing the host immune system to cope better.

What is abundantly clear is that the virus is still very much with us and this is no time to lower our guard. We need to be more vigilant than ever about social distancing and hand hygiene. The DoH still recommends the wearing of masks in public as a way or reducing spread from infected carriers and sufferers. People coming into the office must ensure that they pay attention to the room rules and to using the appropriate entrances and exits. More especially when we are on business in other sites or countries, we must be even more careful or risk endangering our colleagues and with it our reputation.

If history is correct, this could last as long as 24 months unless a vaccine is developed before then.

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CMR Surgical is a private company developing the next-generation universal robotic system for minimal access surgery.

CMR Surgical