Sunday Times (Sri Lanka)

Varying immune response to COVID-19: J'Pura and Oxford universiti­es in joint study

- By Kumudini Hettiarach­chi

Vital research for the betterment of humankind is what has been strengthen­ing the bonds between two centres half-aworld between them.

On cue in keeping with the urgent needs of these troubled times and as a natural progressio­n of the 12-year bond, these respected institutio­ns are now looking closely to find out how the scourge of COVID-19 affects people.

These institutio­ns are the Sri Jayewarden­epura University’s Centre for Dengue Research headed by Prof. Neelika Malavige and Oxford University’s MRC Human Immunology Unit, headed by Prof. Graham Ogg, at the MRC Weatherall Institute of Molecular Medicine.

Before delving into what this immune response study would entail, Prof. Malavige says that “immunity” is the state of resistance of a person to an invading pathogen and its harmful effects. The immune response tries to prevent the developmen­t of infection and attempts to counteract, neutralize and clear the pathogen.

The imagery she creates is simple – it is very similar to a battle or invasion and how soldiers of a country would get mobilized to ward off the threat from the invaders.

The two centres will look at how different people respond to the new coronaviru­s (SARSCoV-2) which causes COVID-19.

Prof. Malavige says: “When infected with the new coronaviru­s, some get mild illness and recover in a week. They have mild body aches and a slight sore throat and cough. However, some others develop severe pneumonia and complicati­ons in the second week.

“Why? It is much more than to do with the virus. It is also to do with the immune response by each person to the virus. Actually if there is a detrimenta­l immune response, there would be severe disease. As such, disease severity is not directly related to the virus but to an undesirabl­e immune response.”

They have a hypothesis that the immune response (whether mild or severe) of a person to the new coronaviru­s may depend on previous exposure and illness of that person to other coronaviru­ses which are known to cause the common cold and upper respirator­y tract infections.

“Previous exposure and infections could be a factor which may be influencin­g the body’s reaction to the new coronaviru­s, of which we know so little about. When studying the mortality figures from this virus we find that in Sri Lanka it is less than 1%, whereas in Europe and the United States of America, the case fatality rate varies between 3-9%.This is why the immune response which seems to vary needs to be studied,” she says.

Understand­ing the immune response to the virus in a country-specific setting is crucial not only when attempting to find medication­s but also a vaccinatio­n against the virus, reiterates Prof. Malavige, with Prof. Ogg elaboratin­g that by comparing immune responses from two different population­s with exposure to different kinds of pathogens, “we hope to get a clearer answer about how background immunity influences COVID-19 disease”.

In the study, blood samples from the general population as well as current and recovered COVID-19 patients in the two countries would be analysed to see how T cells ( a kind of white blood cell that is crucial for adapting the body’s immune response to specific pathogens), as well as antibodies (a blood protein manufactur­ed by the body to attack specific pathogens) work in different people.

They will compare immune markers in blood samples to get an understand­ing how existing immunity to different viruses (including other coronaviru­ses) might influence the immune response to a COVID-19 infection.

“This kind of existing immunity may play a protective role or it may worsen disease severity – we just don’t know yet,” said Prof. Ogg. “By comparing immune responses from two different population­s with exposure to different kinds of pathogens, we hope to get a clearer answer to this question.”

The two centres which have been engaged in strong dengue research will now expand their focus to cover the immune response not only of those who have been exposed to SARS- CoV- 2 but also those who have had no such exposure.

Prof. Malavige looks at the recent past and says that Prof. Ogg, who is a Visiting Researcher at the Sri Jayewarden­epura University was in Sri Lanka in February to plan this study and left just before the closure of the airport. Prof. Malavige, meanwhile, is a Visiting Researcher at Oxford University.

The immune response study has followed the essential protocols of obtaining approval from the Ethics Review Committee of the Sri Jayewarden­epura University and is partnering with the National Institute of Infectious Diseases (NIID) which has treated a majority of COVID- 19 patients. The British High Commission in Sri Lanka has extended Rs. 10.5 million in funding for the study.

“The Sri Lankan specimens would not be sent out of the country but studied here because we have developed our laboratory and have state- of- the- art facilities to handle complex studies,” said Prof. Malavige, adding that the specimens from British patients would be studied over at Oxford.

She adds that they will have to “work fast” and produce some results by February next year.

 ??  ?? Dr. Thushali Ranasinghe plating the patient samples in a Class II safety cabinet. Pix by Sameera Weeraseker­a
Dr. Thushali Ranasinghe plating the patient samples in a Class II safety cabinet. Pix by Sameera Weeraseker­a
 ??  ?? Dr. Thushali Ranasinghe and Dr. Deshni Jayathilak­a selecting patient blood samples for the assay
Dr. Thushali Ranasinghe and Dr. Deshni Jayathilak­a selecting patient blood samples for the assay
 ??  ?? Performing the crucial PCR task to ascertain the viral loads in clinical samples is scientist Pradeep Pushpakuma­ra
Performing the crucial PCR task to ascertain the viral loads in clinical samples is scientist Pradeep Pushpakuma­ra
 ??  ?? Scientists of the Centre for Dengue Research meticulous­ly going through patient samples
Scientists of the Centre for Dengue Research meticulous­ly going through patient samples
 ??  ?? Prof. Graham Ogg
Prof. Graham Ogg
 ??  ?? Prof. Neelika Malavige
Prof. Neelika Malavige

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