Potential vaccine only early next year

No evidence virus is weakening

“The earliest timeline for a successful [Covid 19] vaccine will be early next year. But this presupposes everything goes exactly ideally well. That may be too much to hope for, “ said Chair Professor of Virology at the University of Hong Kong, Malik Peiris in an interview with the Daily News.

“We have to realise that we do not have any vaccine for a coronavirus disease so far. So we have no previous blueprint to follow,” he added.

In 2003, Professor Peiris and his team at  Hong Kong University played a key role in the discovery that a novel coronavirus was the cause of severe acute respiratory syndrome, or SARS and in understanding the pathogenesis of this new disease.

“Unlike SARS 2003, the SARS-CoV-2 [ which causes COVID-19] is very unusual in its ability to transmit very early after the onset of illness and even before the patient develops symptoms,” Prof. Peiris mentioned. 

Prof. Peiris is also an Honorary Consultant Microbiologist at Queen Mary Hospital, Hong Kong.

Excerpts

Q: As we have read Coronaviruses are a family of viruses that can cause illnesses such as the common cold, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).  The first coronavirus was discovered in chickens in the 1930’s and the first human coronaviruses were identified in the 1960’s.

What is the best definition of Coronaviruses ?

A: Coronaviruses are a family of viruses which cause disease in humans and animals. While they cause serious diseases in animals, until 2003, they were only believed to be causes of the common cold. This changed in 2003 when we found that the cause of SARS was a coronavirus. Since then two other coronaviruses which cause severe human disease have been discovered - MERS-coronavirus in the Middle East which has caused human outbreaks but did not become pandemic and SARS-CoV-2 which emerged in late 2019 and  has become pandemic with catastrophic results. 

Q: In 2003, you played a key role “in the discovery that a novel coronavirus was the cause of severe acute respiratory syndrome, or SARS and in understanding the pathogenesis of this new disease.” Can you brief us on this discovery?

A: In February 2003, we heard of an unusual severe pneumonia causing disease in Guangdong Province, China. The urgent question then was to identify the cause of this new disease. We managed to do this and identify that the cause was a new coronavirus which came from animals to humans. Once the cause was identified, we were able to quickly develop diagnostic tests to identify patients with the disease and isolate them. Through this means, we were able to contain the spread of the virus and eventually stop its transmission.  

Q: How do other coronaviruses differ  from SARS-CoV-2, the virus which causes COVID-19?

A: SARS virus in 2003 and the new SARS-CoV2 are closely related to each other and to a number of coronaviruses found in bats. Both (as well as MERS coronavirus) have the capacity to cause severe pneumonia and death. However, unlike SARS 2003, the SARS-CoV-2 is very unusual in its ability to transmit very early after the onset of illness and even before the patient develops symptoms. This makes it very difficult to control. Much more difficult to contain than SARS 2003.   

Q: Way back in 2003, it was your team at the University of Hong Kong  who discovered that SARS virus originated in a species of bats.  But there are contradictory views over the origin of Covid 19. Is there sufficient evidence to state that the virus originated in Wuhan’s Wet market?

A: It is clear that SARS-CoV-2 also originated in Rhinolophid bats. But what is uncertain is how such a bat virus got to humans. It is possible that an intermediate animal species was involved and that is what is being looked for now. In the case of SARS in 2003, the virus jumped from bats to other small mammals such as civet cats and raccoon dogs, all sold as food in wild animal markets in Guangdong. Transmission to humans occurred from these animals. So a similar pathway is suspected to have occurred with SARS-CoV-2.   

Q: Can Covid 19 be transmitted from pet animals? Very few cases were reported of human to animal ( cats, dogs -mammals) virus transmission. But as we know still there is no evidence of animal to human transmission. Reasons?

A: It does appear that the species range that can be infected by SARS-CoV-2 is rather wide - including cats, dogs, tigers etc. These infections appear to be transmitted from humans to these animals.

Q:  COVID-19, SARS and MERS, all three are respiratory   diseases.  However, Covid-19 has killed more people than SARS and MERS combined, despite lower case fatality rate.How does Covid 19 differ from SARS and MERS?  How does it spread?

A: All three viruses spread between humans in similar ways - droplets that are created by coughing, sneezing or even talking which can spread the virus from one person to another. In addition, the virus survives for many days on smooth surfaces - e.g. stainless steel, plastic glass etc. So such contaminated surfaces can be a source for hands to be contaminated and then virus transferred to the eyes, nose or mouth.

The reason why SARS-CoV-2 has caused more deaths is because it has infected much much more people - millions in fact. SARS in 2003 only infected a total of around 8000 people while SARS-CoV-2 has infected millions. 

Q: Air pollution no doubt increases the risk of respiratory diseases. Are researches being done on the relationship between increasing air pollution rate and rapid development of respiratory diseases?

A: It is very likely that air pollution aggravates the COVID19 disease. But this has not been formally proven yet. 

Q: What type of  research is being done by you and your team at the University of Hong Kong on Covid 19 ?

A: Our work has included diagnostic tests for the virus, understanding how the virus spreads and causes disease, experimental animal models to test vaccines and drugs, the immune responses to the virus etc.

Q: Can warm weather curb the spread of the Covid 19?

A: Our work shows that the survival of the virus on surfaces is markedly reduced in higher temperature and humidity. So it is possible that hot and humid weather can reduce transmission of the virus. But it is unlikely to completely stop its spread. 

Q: It was reported that you held a video conference with Sri Lanka’s Health  Ministry’s technical committee on the country’s Covid 19 situation  and  that  you have been advising the Ministry on preventive measures. Are you satisfied with the measures taken by  our Health Ministry to curb the pandemic? What are the  exact areas under your  purview ? ( if there are any)

A: My discussions with the Ministry of Health are confidential. I agree that Sri Lanka has taken very determined steps to contain the virus so far.  

Q: How long will it take to develop a vaccine for the disease?

A: This is difficult to say. The earliest timeline for a successful vaccine will be early next year. But this presupposes everything goes exactly ideally well. That may be too much to hope for. We have to realise that we do not have any vaccine for a coronavirus disease so far. So we have no previous blueprint to follow. 

Q:  As a microbiologist could you elaborate on the latest coronavirus developments and scientific research on prevention? It was reported that a study conducted by a major hospital in Milan, Italy, had found that the viral load present in people who now test positive for the coronavirus is decreasing. Is coronavirus really weakening now?

A: I do not believe there is any evidence that the virus is either weakening or that it is becoming more severe. It is spreading very efficiently and continuing to do so.

Friday, June 12, 2020 - 01:00


source http://www.dailynews.lk/2020/06/12/features/220522/potential-vaccine-only-early-next-year

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