COVID-19: Some more discerning reflections

By Dr. B. J. C. Perera
Specialist Consultant Paediatrician

In the setting of a major contagion COVID-19, caused by an entirely new organism which is causing absolute havoc all over the planet, there are many things that gradually come to light as the world staggers its way through the pandemic. It is true to say that the scenario is in a state of flux with many still unanswered questions. As things develop our knowledge base too gets extended, sometimes in considerable amounts and occasionally in leaps and bounds as well. Quite a few of the original thoughts on the subject have had to be either withdrawn, modified and even completely revised in the light of newer knowledge. This is something to be expected as it is the very nature of progress in science. When more information is available and some things have had to be revised, it is not a reason to cause aspersions to be levelled against the original pronouncements or the people who propagated those. The basic content which have then had to be revised had to be undertaken through necessity. It has to be acknowledged that, from a medical point of view, all necessary steps have indeed been taken in good faith.

Not all that long ago, the thinking was that this disease was primarily transmitted through droplet infections following sneezing, coughing and even talking by those affected by the virus and that it was the primary route for human to human spread of the disease. The aerosol droplets so created generally had a possible transmission distance of perhaps around one metre. The need for physical distancing of people for a separation of at least one metre originated from this argument. Additionally, in the face of that same contention, the wearing of face masks by those affected by the virus and good cough etiquette of the same group were also promoted as a means of controlling the spread of the disease.

However, one of the more recent developments that has made it necessary to change some of our practices is the accumulation of more and more evidence for the possibility of air-borne transmission of the disease. This means that very fine droplets containing the virus may be carried through the air, perhaps for distances greater than one metre, and worse still, they may remain suspended in air and be floating about for quite some time. Added to this is the information that the virus could survive on surfaces on which it is deposited for considerable periods of time, which per se increases the potential infectivity of the virus. All these bits of data that have come to light makes the proper wearing of face masks by everybody becoming quite a lot more significant and all that much more important. Although some of the face masks do not provide a fool-proof one hundred per cent guarantee of defence against infection by the virus, properly worn masks will be able to provide a certain degree of protection. For an enhanced degree of safety, one needs to resort to the wearing of specialised masks which are specifically designed to protect against even the viruses. It is pertinent to point out that in the light of the latest information, if and when the schools reopen, the wearing of face masks by students within the school, and for that matter even from the time they leave home, becomes a really necessary measure. The current stipulations by the health authorities regarding this, where they imply that wearing of masks in school is not all that necessary, will need to be changed accordingly and perhaps sooner rather than later. These newer bits of information also make, physical separation of individuals everywhere and stringent hand-washing wherever possible, as well as the use of hand sanitizers and antiseptic cleaning of surfaces, even more important than ever before.

It is well-known by now that the major brunt of the damage caused by the virus in COVID-19 is borne by the respiratory system, especially the lungs. Initially it was just thought to cause a severe pneumonia which is mainly an inflammation of the gas-exchanging components of the lungs. In very simple terms, the air exchanging components of the lung become solid due to the inflammation. However, there is emerging evidence, at least in some cases, of a major involvement of the blood vessels that supply the lungs as well. Of course, there are reports of many other organs being involved in a multi-system attack by the virus and the degree to which they are involved would be reflected by the general severity of the disease. Although a significant proportion of people who are infected by this coronavirus may remain without symptoms, extensive investigations such as special scanning techniques, have shown that even in some of them, there is evidence of lung involvement although they do not show any major symptoms. These newer findings have obvious implications for the management of even symptomless COVID-19 infected persons, who are prime candidates for dissemination of the virus as well.

Cough, breathlessness and reduction in the oxygen content of the blood are the important manifestations of lung involvement. When the blood oxygen levels fall, the increase in the rate of breathing, difficulty in breathing and increased work of breathing are the signs that are seen. Some compensatory mechanisms employed by the respiratory system lead to an increase in the rate and depth of breathing. External oxygen for breathing has to be provided for these patients and those who are severely affected may need mechanical ventilation where the entire process of inflation and deflation of the lungs to facilitate gas exchange is taken over by a machine. Some severely affected patients have needed mechanical ventilation for prolonged periods of time even extending on to several weeks. Early chest physiotherapy to facilitate breathing, maintenance of the patency of the airway tubes and lung expansion in the acute phase, are invaluable for recovery. These are the initial steps in the process of lung recuperation, pulmonary rehabilitation and restoration of the functional capacity of the respiratory system, which will be a prolonged process extending on to the times even after discharge from hospital. There is some suspicion that even after apparent recovery, some patients may show evidence of residual persistent lung damage and that they would really need protracted efforts to improve their lung functions. Many of those who recover would need training on specific breathing patterns and tailor-made physiotherapy manoeuvres. In addition to physiotherapy aimed at the respiratory system, they may have extreme muscle weakness and profound tiredness as well as several psychological disturbances. They would benefit from aerobic exercises, muscle strength improving resistance training and general physical training procedures.

There are some recent concerns regarding the ability of humans to mount a sustained level of immunity to the virus even following recovery from the situations where persons have been infected by the virus. The affected persons may be with or without symptoms but the degree to which their bodies can resist a second infection and protect them against a subsequent infection is the important component for immunological considerations. There is some evidence, at least from several recent studies, to suggest that the immunity acquired as a result of infection may wane off in a matter of a few weeks or months.

Even if the antibody levels go down, whether the already sensitised immune cells of the body would be able to mount an enhanced protective response when exposed to the virus again is the crucial matter for consideration and contemplation. What we do not know is whether these people who have recovered are either resistant to reinfection, or are even a little more susceptible to reinfection by any chance or are likely to develop a more severe illness if re-infected; the latter being reminiscent of what happens in some cases of dengue. Uncertainty regarding these aspects would cast doubts on the postulations on ‘herd immunity’ being a useful element in our efforts towards keeping the virus at bay. That type of general immunity in the population is the prospect of a sufficient proportion of the populace gaining a degree of immunity which prevents the virus from getting into the herd and producing an epidemic or a pandemic.

The immune profile of the virus also has some implications for the development of vaccines against SARS-CoV-2 bug that causes COVID-19 as well. There is a keenly contested race on at the moment as several countries and a whole host of pharmaceutical companies are engaged in many endeavours to produce a successful vaccine against COVID-19. Any useful vaccine would need to maintain a high level of neutralising antibodies against the virus for a significant length of time. If, just like in the case of natural infection, the antibody response following vaccination is short lived, then one may need to administer several doses of the vaccine or it may need to be given repeatedly at pre-determined time intervals. An ideal vaccine would be one that will provide long-term protection following the administration of just one or two doses. Extensive clinical trials on volunteers of different age groups, with repeated measurement of antibodies would be required to determine the efficacy and cost-effectiveness of any future vaccines. It will be an expensive and labour-intensive protocol to test out such a vaccine in the forthcoming months and years. Yet for all that, it would be an absolutely essential undertaking before the usefulness of a future vaccine could be unequivocally established. It must also be clearly stated that an effective vaccine is a dire necessity and the companies or institutions that could produce such a vaccine is in line for absolutely massive financial benefits as a result of the discovery of an effective vaccine.

The next few months would be crucial in a quest towards improving and fine-tuning our knowledge about this little virus that has been able to induce even powerful nations to keel over and even be at the mercy of the bug without any respite in sight. This tiny bug has shown in no uncertain terms how much the human race is vulnerable, in spite of the degree to which nations and technology have advanced. We would need to keep on learning on very many different facets of the virus and of COVID-19 disease caused by the virus. Scientific collaboration among the best brains across all areas of the planet would be the need of the hour in a determined mission towards winning the war against this coronavirus. It will not be a venture beyond us if only we decide to put aside petty differences and concentrate on the matter at hand, as a committed global humanitarian initiative.