Coronavirus: Scientists explain why understanding the virus and developing a vaccine will take time
It has been two months since the new coronavirus outbreak and since then, several scientists across the world have conducted multiple studies in an attempt to learn about the disease and stem its spread.
However, despite global efforts and some progress, it has been very challenging to understand COVID-19’s moves and create a vaccine. The reason is that the deadly new coronavirus is moving very fast. While any new disease takes time to understand, this one was made more difficult because it emerged during the flu season with flu-like symptoms.
“Absence of time (is the reason why it is so difficult to understand). There are massive efforts to learn about it but we have only known about this virus since January. Much has been achieved in a very short time, but the virus is also moving at a fast pace with a starting point in a heavily populated megacity,” Dr Ian Mackay, Associate Professor at The University of Queensland, Australia, tells MEA WorldWide (MEAWW)
“This isn't an Ebola virus disease outbreak in a small remote population. Time was always going to be our biggest enemy when dealing with a respiratory virus that spreads effectively, via several avenues, from mildly ill humans, as SARS-CoV-2 does,” says Dr Mackay. He designs, validates and employs molecular techniques to support clinical and public health needs, helping to discover and characterize known, new and newly-identified and rare viruses.
According to Dr Tom Koch, adjunct professor, Department of Geography, The University of British Columbia (UBC), Canada, when a new disease appears — bacterial, fungal or viral — there are always more questions than answers. And some of those questions can only be answered over time.
“In this case, the first job was to realize this virus was new and distinct. That was not as easy as it sounds because it appeared during the annual flu season and presented with similar symptoms. Then, once a new thing is recognized, the question becomes what is it? With remarkable speed it was identified as a new member of the class of coronaviruses distinct from SARS, MERS, etc,” Koch tells MEAWW.
What we do not know yet accurately is the incubation rate, the immunology of the virus to help with vaccine development, and the time it takes for the virus to mature in an infected person before he or she displays symptoms.
“Varying estimates have been made. We don’t know when the incubating virus may become infectious—is it before symptoms appear? We don’t know the Ro rate, a measure of its infectiousness (how many people are infected by any one infected case). And we’re still not sure of the mortality rate (deaths from the virus) or the relation of those deaths to secondary conditions. For example, if the virus leads to pneumonia or causes those immunologically compromised to die from an underlying cause,” explains Dr Koch.
He adds, “All these are things we learn as an epidemic matures. And much of it is conditional. For example, the mortality rate will be far higher in countries that do not have robust health systems and the rate of infection may be far higher in countries where active vigilance is begun early (for example, Canada and the US) than in others, like China, where the disease had an early and robust foothold.”
Dr Koch, however, says that experts went through a similar learning curve with SARS and then, later, MERS.
Scientists say that research is the key to our understanding of the virus and minimizing its impact and that experts need to evaluate the scientific evidence as it accrues
Dr Stephen A Hoption Cann, Clinical Professor, School of Population & Public Health, University of British Columbia, says that the recent report by the Chinese Centers for Disease Control and Prevention (CDC) has helped fill in a lot of gaps. This includes as to who is most vulnerable to developing severe illness or dying from the virus, which includes the elderly and patients with other health conditions such as cardiovascular disease, diabetes, lung disease, and high blood pressure.
However, says Dr Cann, experts still need to find better ways to prevent and treat the disease. This includes studying antiviral drugs or developing new ones and also testing vaccines to see if COVID-19 can be prevented.
“We are slowly finding out more about how infectious the virus is (in fact we now know that it is quite easily transmitted from person to person, unlike what was initially thought). But one must keep in mind that only a month ago there were less than 1% of the cases that we have now. We have learned that it does seem to be similar to SARS, though the death rate is lower than SARS overall,” Dr Cann tells MEAWW.
Vaccines can be tricky, and cannot be developed overnight
Multiple organizations, including the National Institutes of Health, are working to develop a vaccine for this new strain of coronavirus. And the World Health Organisation (WHO) recently said that it may be 18 months before a vaccine against the coronavirus is publicly available.
According to experts, vaccines are tricky things to create. They often take years and there is no guarantee this virus will not mutate into a form that tentative vaccines, eventually tried, will not affect.
“But remember that all the major vaccines took decades to develop (think polio). The idea we can fashion one quickly for a new virus is unrealistic,” says Dr Koch.
Others agree. Dr Cann explains that while vaccines can be developed now much more rapidly than they could in the past, one still has to carry out clinical trials to determine whether the vaccine is effective in preventing disease.
“One may develop a vaccine to certain components of the virus, but it may not lead to effective protection against the virus – we cannot know this until clinical trials are completed. There are many groups now trying to develop a vaccine to COVID-19, but it probably will not be ready for use in the general public until next fall or winter,” he says.
There are other reasons, say experts. According to Dr. Mackay, there has not been urgent pressure to develop a vaccine in recent years.
“Once SARS-CoV was eradicated, the urgency was reduced. MERS-CoV vaccine work is ongoing but simply stopping unprotected contact with the camel source is also an effective way to halt its acquisition. Now we have an urgent need to develop a vaccine for a virus family that has yet to see a licensed and effective vaccine developed for humans. The clock is running and lives are on the line,” he tells MEAWW.
Researchers also argue that no single institution has the capacity or facilities to develop a vaccine by itself as there are multiple stages and processes involved. This is why institutes must work together, write experts in The Conversation.
“If a vaccine is found to be safe and effective, it will need to pass the necessary regulatory approval. And a cost-effective way of making the vaccine will also need to be in place before the final vaccine is ready for delivery. Each of these steps in the vaccine development pipeline faces potential challenges,” write Rob Grenfell, Director of Health and Biosecurity, CSIRO, and Trevor Drew, Director of the Australian Animal Health Laboratory (AAHL), CSIRO.