Dr Pasano Bojang: COVID-19: Beyond the Noise
Updated: Jul 31, 2020
Friday 31 July | COVID-19: Beyond the Noise | Featured
COVID-19: Beyond the Noise
My intention for this write up is to discuss areas of COVID-19 disease that might benefit our communities: COVID-19 infection & re-infection rates, mutability (i.e. mutations rate), current opinion on chloroquine (CQ)/hydroxychloroquine (HCQ) as treatment modalities, and Africans as Guinea pigs in COVID-19 vaccine trials.
What I want to convey here is grounded on scientific work, not political rhetoric, opinions or beliefs - religious or otherwise. My intentions is to clear out the noise vise versa some of these rhetorics. In times like this, our society should be protected from such rhetorics. My choosing of these areas of discussion is centered on the social structure of our communities, the availability of chloroquine/hydroxychloroquine off label for treatment of malaria, our believe system and the information storm from social media platforms. I felt we need to know the truth from falsehood, arm and protect ourselves and our families from Covid-19.
COVID-19 is an RNA enveloped virus that is believe to jump from Bats to human by acquiring the ability to infect human cells. Covid from Bats and COVID-19 are 96% similar in sequence hence the believe that it is acquired from Bats. COVID-19 infect human through the Angiotensin Converting Enzyme-2 (ACE-2) expressed in the lungs and to a higher degree in the month. This is the reasoning behind the covering of the mouth and nose. What we know as of now is that a single infected COVID-19 patient can transmit the disease to 2-3 peoples in European settings. This number is likely to be greater in African settings with smaller duelings and larger concentrations of people. The number also greatly changes if social distancing guidelines and wearing of face mask are not followed. So please wear face mask to prevent transmission especially during the tobaski period.
COVID-19 patients are either symptomatic or asymptomatic. Here I will buttress the main clinical symptom of asymptomatic patient: Anosmia which is the loss of sense of smell. According to CDC best scenario estimate asymptomatic patient constitutes 40% of all COVID-19 patients and are responsible for 75% of new infection. This suggest robust testing to enhance early detection and treatment.
COVID-19 re-infection rate is not alarming but is seen in patients who previously have mild COVID-19 disease. The good thing here is that this is not due to mutation of the COVID-19 virus. Rather, this is attributed to loss of antibodies (soldiers) over time. According to recent findings, the half life of COVID-19 antibody is 36 days. This means that if COVID-19 produced 10 soldiers on day one, by day 36, these soldiers will be reduce to 5 and 2-5 by day 72. This gradual loss eventually make these patients susceptible to re-infection. This is the reason vaccine boosters are given.
The mutation rate of COVID-i 9 is not different from that of the flu virus. In fact some estimate showed that COVID-19 mutation rate is lower. This does not mean a less lethal virus if mutation occurs. What we know is that the original virus has recently mutated into a more infectious strain (D614G strain). The change (mutation) increases the efficiency of the interaction between the spike protein of the virus and ACE-2 receptor. This mutant is responsible for my majority of infections outside of china. Patients infected with these strain have more RNA particles in their blood compared to those infected with the original strain. The good news here is the disease outcome have not change for the two strains. Why Am I talking about mutation here? This is because mutation rate is greatly influence by selection pressure. The more pressure that is put on the virus the more it tries to change to evade that pressure. With every Malang, Bakary and Ahfang coming up with COVID-19 treatment. These remedies can inadvertently induces or provide the environment for the virus to mutate into a more infections a lethal strain. Thus, I cautioned against unproven and untested remedies.
The recent rhetoric about chloroquine (CQ) and its derivative Hydroxychloroquine (HCQ) as a cure of COVID-19 is a perfect example. At the molecular level, these drugs have been shown to prevent viral entry by inhibiting glycosylation of ACE-2 receptor. In layman term, the drug change the key combination so that the virus cannot enter the cells. Both drugs have also been shown to prevent the uncoating of the viral particle/package (envelope) thereby inhibiting replication of viral RNA. What does this mean? The virus enters human cell in a package (envelope) form. Once inside the cells, it needs to shed of the package to allow replication of its RNA. The lysosome inside the cells are responsible for this because of their acidic content. Both CQ and HCQ make lysosome more basic thereby increasing their pH and preventing both the un-packaging and vesicular fusion ( endosome and lysosome fusion). From the study of human cells outside the human body, these drugs are effective. However recent clinical studies in Brazil and NIH (US) have shown that these drugs did not perform better than standard treatment. The Brazilian study warn against the use of these drugs because of their potential toxicity. NIH discontinued their studies because the results are innocuous: no harm or benefit. Because of the effect of these drugs on the life cycle of the virus, I speculate, they might induce selection pressure on the virus which can lead to generation of more lethal and/or infectious stain under unregulated treatment conditions. With current spike of the virus in The Gambia and readily availability of these drugs (use in malaria treatment and in some dark skin individuals these drugs may also be itchy), the use of these drugs should monitored and controlled if possible. More importantly, these drugs are not cures of COVID-19 disease and off label use should be avoided. Lastly, because of the inclusiveness of data from clinical trials, more trials are needed to clarify the effectiveness of these drugs against COVID-19. Until a vaccine is made, the debate about COVID-19 will continue.
The last part I want touch pertains to COVID-19 vaccinations and our involvement in vaccine trials. Should African be part of the vaccine trials and are Africans going to be used as Ginea pigs? I understand the skepticism and where it’s stemming from. It will be both an economic and health catastrophes if African refuse to take the vaccine. While, I believe African will take the vaccine when given to them, I think most will be reluctant to take part in vaccine trials. I think its important we take part in vaccine trial too. Why? Africa is no longer a dark continent where we are at the mercy of the colonial masters. Second, Vaccine trials are not run in the dark, they monitored and supervised by review boards for any potential harm. Whenever an unfavorable outcome is detected, the trials are terminated or adjusted to ameliorate the harm. More importantly, proper consent of trial participants means all involved knows what they’re getting into. Third, the safety of any vaccine must be tested en masse in different populations. Although we are the same in many ways, variations in our DNA sequence can affect our response to drugs including vaccine. Vaccine that worked effectively in European work as effective in Africans? Maybe but this need to be determined and not assumed. I think the later will increase the mistrust.
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