The College of Community Physicians of Sri Lanka held a webinar on 30 December to serve as an update to medical professionals and the general public on the Public Health Response to Covid-19, in response to the need to discuss the implementation of public health measures following the second wave of Covid-19 infections.
The webinar was moderated by Hasith Tissera, and chaired by College of Community Physicians of Sri Lanka President Dr. Nihal Abeysinghe and Vice President Dr. Sudath Samaraweera.
The webinar panel included eminent virologist and University of Hong Kong Chief of Virology Prof. Malik Peiris and University of Sri Jayewardenepura Department of Immunology and Molecular Medicine Head Prof. Neelika Malavige.
Prof. Peiris, whose work specialises in emerging viral diseases, shared that the pandemic has shown the world the importance of public health, adding that it is not rich countries who have handled Covid-19 the best, but countries with good, strong public health responses, highlighting that public health and community medicine are fundamentally important when it comes to dealing with public health and national health crises.
Prof. Peiris also spoke about the nature of viral mutation, explaining that mutations take place when RNA within viruses undergo changes when multiplying, sharing that this happens less in coronaviruses than other viruses like HIV.
He added that most mutations are bad for the virus and hinder their survival. However, some mutations strengthen the virus’s chance of survival, changing its properties in some way that increases its capacity to spread. Speaking of Covid-19, he said that the virus has spread worldwide, and that virologists are seeing more and more diversity in Covid-19 mutations.
Studying the sequence of these mutations can help answer questions like if all cases in a specific cluster are caused by the same virus, how they link to other clusters around them, and what specific mutations and properties they have. Prof. Peiris noted that, at present, the most viruses are of the strain “D614G”, and that this is most likely because of its transmission fitness.
Commenting on the new, more virulent strains of Covid-19 to hit the UK and South Africa, Prof. Peiris explained that this was likely because the virus had been able to mutate and evolve in an “unusual host” for a long period of time – possibly an immunocompromised person with a persistent infection.
Prof. Peiris stressed that there was no evidence of these newer strains being more severe or being immune to vaccination, although the strain has spread significantly across the globe with imported cases being found in the UK, Denmark, Australia, Japan, Brazil, South Korea, the US, Singapore, and Hong Kong. Prof. Peiris also noted that even if this newer strain were to reach Sri Lanka’s shores, it would be controllable using public health measures, but that we would need to work harder to be successful at controlling it.
Prof. Malavige spoke about diagnostics and vaccines for Covid-19, sharing that Sri Lanka presently conducts about 12,000 PCR tests daily, with a 4.2% positivity rate. She also shared that virologists have been sequencing the virus since early March, and shared that research shows no links between previously discovered clusters in Sri Lanka and the Minuwangoda cluster that began Sri Lanka’s second wave of Covid-19.
She also noted that research showed that the Peliyagoda cluster which followed the Minuwangoda cluster was, in fact, the same virus, and therefore part of the same cluster. Speculating on how this second wave could have reached Sri Lanka, Prof. Malavige posited that it likely came from gaps in quarantine processes or from illegal immigrants, among a host of other possibilities, explaining that there are innumerable ways for a virus to reach Sri Lanka.
Prof. Malavige noted that while the current strain of Covid-19 in Sri Lanka is different from the strains we were experiencing pre-October, they are still effectively eradicated with the vaccines that have been developed.
Prof. Malavige also spoke about the diagnostic process of Covid-19, sharing that both PCR tests and rapid antigen tests each have their positives and negatives, especially when there are delays in reading results, and that this can often lead to false positives.
Discussing vaccines, Prof. Malavige stressed that despite the accelerated development of these vaccines, all procedures have been followed in the development process, minimising risk. She also noted that a major challenge will be deciding who gets the vaccine and when, because of supply and demand. She added that those most at risk, such as those with comorbidities like diabetes and cancers, the elderly, and healthcare workers, will likely be prioritised. Meanwhile, other factors, like the availability of vaccines, logistics like cold storage facilities, and funding, will also play a role in how widely and effectively we can vaccinate as a nation.
Prof. Malavige stressed that vaccines are very important. Apart from the health significance, and being able to effectively control the virus in the long term, there is also a huge economic benefit to being vaccinated as a nation, highlighting that a safe vaccine is definitely the way forward on all fronts, and instrumental in achieving zero transmission or a state close enough to zero transmission, where we can treat Covid-19 like the common cold.
The panel also addressed the issue of burying victims who have succumbed to Covid-19, commenting that there is no risk of Covid-19 being transmitted through solid and groundwater, given that the virus would need to travel through physical filtration barriers and then through the soil to reach water sources, and it could not survive this.
The panel reiterated that the public health measures in place go a long way towards minimising spread, and urged the public not to propagate harmful myths related to healthcare.