New medical research - April 26

NEW MEDICAL RESEARCH ON COVID-19
and the open questions 

Checking blood pressure in Iraq, April 4

Since our first post   on April 1 describing what was known of the virus, many research projects are under way looking at the virus, the existing treatments and the equipment. In this post we summarise what is new and what is not known at April 26.

The virus

Very little new information has emerged publicly about the virus itself, apart from what was originally reported by the Chinese and what has been extrapolated from the SARS-1 and MERS outbreaks. 

Related deaths

Some new discoveries have been made. It is believed  that cytokine storms from an overactive immune reaction to COVID-19 can flood lungs and 'take out' damaged organs in toxic shocks - as occurs with avian influenza. As well, some COVID deaths in younger patients with mild to no symptoms are associated with strokes, that were initially thought to be unrelated.

It appears that CV inflames the walls of larger arteries causing thrombosis. A significant proportion of critical-care patients in New York and the Netherlands had thrombotic complications.  In one CV patient, the surgeon watched new brain clots forming in real time.   

Associated factors

 Age, other serious conditions ('comorbidities') and to a lesser extent obesity have correlated with the mortality rate. A study has suggested smoking may actually be helpful since it coats lungs in protective tar. A new theory has suggested that blood pressure treatments may contribute. Three quarters of hospitalised COVID older patients had hypertension. COVID can hitchhike on the ACE2 enzyme encouraged by these drugs.

The very high death rate in Italy from all sorts of pulmonary conditions has yet to be explained. 

Equipment

Masks

Initially many countries did not recommend that people wore face masks, saying cheaper masks did not block the virus. The real problem however seems to have been that most countries did not have an adequate supply of masks.

Soon some studies showed that even makeshift masks could block three quarters of mouth droplet emissions, and this would be a big help in limiting super-spreading. Accordingly, Austria issued a requirement that masks should be worn in food stores - and they have been the only country in mainland Europe to suppress their epidemic. Now, many more countries are requiring the wearing of masks in situations where social distancing is not possible. 

Ventilators

Lung blockage in a COVID patient 

Intubation through mechanical ventilator machines was initially applied to almost everyone with respiratory distress (ARDS). These machines are expensive, and patients have to be sedated. A shortage soon developed, during which other methods were tried - which quite often worked! 

Ventilators are hardly ideal since half the patients that go on them for the required two to three weeks die (a British study gave two-thirds), and they can cause long-term lung damage. Increasingly, hospitals are only using them for patients whose blood oxygen drops (hypoxia) - common in SARS severe cases.  

Other possibilities include CPAP (anti-snoring) machines and oxygen masks, which are much cheaper and do not require intubation, or being watched by a staff member (as successfully used with British PM Boris Johnson. This latter unfortunately has a high incidence of cross-infection as well as being very staff-intensive.

Mechanical ventilators are essential if cytokine storms begin, and some large firms have repurposed to deliver these.    

Responses

It is now well established that lockdown can arrest the progress of an epidemic. For example, Australia hit its inflection point exactly five days after a L3 lockdown was instituted on March 25. Five days is the average time for symptoms to show. 

The problem is that no-one knows exactly what lockdown is necessary in what circumstances. Of four countries that were successful in suppressing substantial epidemics, Korea is using L2, Australia L3 and New Zealand and Wuhan, L4. These all have very different social costs and the more stringent ones might result in widespread famine in poorer countries.

With over 3 billion people under quarantine, the public in some countries are starting to protest about higher level lockdowns. They may not be sustained much longer as they require general compliance.

Vaccine

No vaccine has ever been developed for a coronavirus - or for most other forward RNA viruses. Some 70 vaccines are being developed around the world. Vaccine development usually takes about ten years, but the process is being very substantially accelerated given the crushing death toll. Coronavirus does not manifest well in animals, and testing is going immediately to human volunteers.

The vaccines have first to show they produce an immune response, second that they give protection, and third that they are safe. The latter is important since some immune enhancements can actually make diseases worse.

According to Nobel Laureate Peter Doherty, a vaccine will be developed and may be available by September. 

The questions

None of the following is actually known about COVID 

• how it spreads 
• what the infection rate is 
• what the death rate is 
• what the factors that increase mortality are 
• what are the proportion of symptomless 
• whether symptomless people can spread the virus
• why children barely get it at all, 
• why younger people rarely have serious cases
• whether having had the disease gives immunity, and for how long

Some of these are very important in determining what supplies are required, what type of quarantine to apply, and when to relax restrictions.

NOTE: We will extend this piece and add further references as they become available.

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