Three-year wait possible
Team at vaccines facility in preliminary stages of developing a prototype
The coronavirus that caused the SARS outbreak and the 2019-ncov “are probably between 75 per cent and 80 per cent similar at a genetic level … and are part of the same subgroup of coronaviruses,” said Dr. Samira Mubareka, an infectious disease consultant at Sunnybrook Hospital.
They are somewhat similar in the sense that both viruses are “transmitted by the respiratory route” and attach to the same host cell receptors, she said. “However, that’s not enough to say that they are the same virus.”
The data from SARS and MERS (Middle East Respiratory Virus) have helped identify the antibodies that protect host cells against a coronavirus spike protein, which rests on the surface of the virus cell, Falzarano said. This helps scientists save time on research.
“There are different strategies that you can use to make a vaccine like that, but that’s a starting target,” he said. Researchers had worked on a potential vaccine for SARS in 2003 and then again for MERS 10 years later. But both outbreaks were contained before the prototypes went to trial, and the vaccines were shelved.
According to The New York Times, researchers at the National Institute of Health in Maryland modified the genetic code in a template for a previously developed SARS vaccine in the hopes that it could treat the new virus.
However, Falzarano is doubtful as to whether a SARS vaccine could be used to treat the novel coronavirus. “It’s related, but it’s not that close,” he said. “Of course, repurposing a SARS vaccine that maybe never made it into clinical trials but made it far through animal testing would still be quicker than starting from the beginning again. We don’t know for sure, as yet, if that’s the case, but it kinda looks — based on some data that people have reported — that it would not be protective.”
It’s “possible” that the coronavirus outbreak could be contained before the vaccine is deemed ready. “At this stage, it appears that it could be less severe than MERS,” said Mubareka, adding that it’s still hard to say given how early it is.
Efforts to contain outbreaks have improved since SARS. It took five months after the SARS outbreak for American and Canadian authorities to sequence the genome of the virus. This time, Chinese scientists released the data sequence of the genome for 2019-ncov within weeks of the announcement, allowing scientists to begin work on a vaccine earlier than last time.
“SARS was very difficult, it (relied) on a lot of observational stuff,” said Mubareka. “And people were doing all kinds of different things — steroids, interferon — and things could have gotten better or worse regardless of what we did because there was no clear trial or study.”
Now, she said, medical professionals are looking at approved anti-viral drugs and treatments to treat patients if their symptoms don’t go away naturally. “Things are a little bit better.”
Falzarano agrees that it is possible for the outbreak to be contained before a vaccine is ready. “But we don’t know that, right, that’s very hard to predict,” he said. “It could be that it’s just worse. Of course we should hope that public health measures and quarantine are able to contain that on its own. But that shouldn’t mean we should sit around and see what happens. Seems irresponsible.”
While “it would be great” if the outbreak were to be contained quickly, Mubareka cautions against allowing production to go down the same route as the previous prototypes. “It might be hard to test if it does get contained” due to a lack of candidates for clinical trials, she said, but the knowledge gained from developing the vaccine could be useful should there be a separate outbreak in the future.
“If it does get contained initially, (the vaccine) could be applied should the virus reemerge,” she said. “It’s highly unlikely, but we should learn to never say never.”