Why are ‘young & healthy’ Covid-19 patients being more vulnerable?

While the daily cases for Covid-19 in Malaysia are on the rise again, a record 135 new fatalities in a single day was the highest ever documented (on 8th July 2021) and this would bring to a total of 5,903 deaths in Malaysia (till 9th July 2021, WHO report: https://covid19.who.int/region/wpro/country/my) since the start of the pandemic.

Comparing to the SEA countries, Malaysia is the third highest in the accumulated Covid-19 cases which eventually has created many waves of panic among its people. However, Malaysian Science, Technology and Innovation Minister, Khairy Jamaluddin has said that the death and the hospitalization rate in Malaysia started to show a declining trend since the National Covid-19 Immunisation Programme took place. He quoted that “the new way of looking at Covid-19 after we have reached a certain threshold of vaccination is not in the case numbers” and “the case numbers may be high but it's not about suppression anymore but mitigation to ensure people don't die of Covid-19” (1). He elaborated further taking England as an example. The recent EURO 2020 has seen the Wembley Stadium full of football supporters (sadly England lost to Italy in the final) despite the new daily cases raising to 30,000 (due to the Delta variant). This shows how Britain devise their strategies in mitigating Covid-19 rather than focusing too much on the daily case numbers.

The Covid-19 death rate in Malaysia is comparatively lower in the SEA region with 0.73% despite recording 808,658 accumulated cases (till 9th July 2021). A significant number of these cases were also linked to the preexisting morbidity in the deceased. Only Viet Nam (0.42%), Timor-Leste (0.26%), Laos (0.12%) and Singapore (0.06%) documented lower death rate compared to Malaysia. Singapore especially had witnessed only 36 deaths out of 62,668 reported cases. The question is why the Covid-19 death rate in some regions are lower despite recording high daily cases (and vice versa)? Are people from these regions had acquired specific immunity against the virus while the others are being more vulnerable? Or the answers simply hidden beneath our genetic predispositions? As we must learn to ‘live’ with Covid-19, the above questions may get us some glimpse on why many ‘young & healthy’ people are dying out of Covid-19.

We are well informed that the virus (SARS-CoV2) spread through infectious respiratory fluids Inhalation and contagious from human to human who comes in close contact. Thus, self-protection such as wearing face masks and social distancing was among the preventive measures recommended by WHO, however, lesser is known that the susceptibility and the severity of COVID-19 are likely to be associated with host genetics too. A study conducted in 49,562 Covid-19 patients from 46 studies across 19 countries had learnt that there are at least 13 vulnerable loci (where genes are located in chromosomes) implicated to patients with severe Covid-19 condition. The loss-of-function mutation in the type I interferon (IFN) and the genetic alteration in the locus 3p21.31 were among those found to be susceptible in Covid-19 patients (2).

While death among the obese, diabetes and other underlying health conditions were the main reasons in Covid-19 patients, the findings from these studies could explain why Covid-19 is highly susceptible in many ‘young and healthy’ populations. Understanding the genetic predispositions in Covid-19 can therefore provide novel biological insights into disease pathogenesis besides aiding in development of novel therapeutic drugs for Covid-19 treatment in future.

1. Malaysia should change way it looks at daily Covid-19 cases as more get vaccinated: Khairy, SE Asia News & Top Stories. The Straight Times Available at: https://www.straitstimes.com/asia/se-asia/malaysia-should-change-the-way-it-looks-at-daily-covid-19-cases-as-more-people-get. (Accessed: 12th July 2021)

2. Mapping the human genetic architecture of COVID-19. Nature (2021). doi:10.1038/s41586-021-03767-x