The hope is that we will have a corona virus vaccine in 12-18 months, but for that to happen we may have to rely on untested techniques – and that comes with its own risks.Corona viruses are a group of viruses that usually cause mild illnesses, such as the common cold. However, certain types of corona virus can infect the lower airway, causing serious illnesses like pneumonia or bronchitis. Most people get infected with corona viruses at some point in their lives and the majority of these infections are harmless.
Chinese health authorities sequenced the genome of the new corona virus and shared the information so that authorities in other countries can also test people for the virus.
Corona viruses replicate their RNA genomes using enzymes called RNA-dependent RNA polymerases, which are prone to errors, but genomic analysis so far suggests that covid-19 is mutating slowly, reducing the chance of it changing to become more deadly.
There are currently no vaccines or specific drug treatments for corona viruses, but efforts to develop a vaccine are underway and HIV and Ebola drugs are being tested in people with covid-19.
All vaccines work according to the same basic principle. They present part or all of the pathogen to the human immune system, usually in the form of an injection and at a low dose, to prompt the system to produce antibodies to the pathogen. Antibodies are a kind of immune memory which, having been elicited once, can be quickly mobilised again if the person is exposed to the virus in its natural form.
Traditionally, immunisation has been achieved using live, weakened forms of the virus, or part or whole of the virus once it has been inactivated by heat or chemicals. These methods have drawbacks. The live form can continue to evolve in the host, for example, potentially recapturing some of its virulence and making the recipient sick, while higher or repeat doses of the inactivated virus are required to achieve the necessary degree of protection. Some of the Covid-19 vaccine projects are using these tried-and-tested approaches, but others are using newer technology. One more recent strategy – the one that Novavax is using, for example – constructs a “recombinant” vaccine. This involves extracting the genetic code for the protein spike on the surface of Sars-CoV-2, which is the part of the virus most likely to provoke an immune reaction in humans, and pasting it into the genome of a bacterium or yeast – forcing these microorganisms to churn out large quantities of the protein. Other approaches, even newer, bypass the protein and build vaccines from the genetic instruction itself. This is the case for Moderna and another Boston company, CureVac, both of which are building Covid-19 vaccines out of messenger RNA.
China embarks on clinical trial for corona virus vaccine
China has started the first phase of a clinical trial for a novel corona virus vaccine, records show, as the world’s scientists race to find a way to combat the deadly pathogen.
It comes after US health officials said last week they had started a trial to evaluate a possible vaccine in Seattle.
The Chinese effort began on March 16 — the same day as the US announcement — and is expected to continue until the end of the year, according to a filing in the country’s Clinical Trial Registry, dated March 17.
“Volunteers of the COVID-19 phase one trial have already started receiving the vaccine,” a staff member involved in the government-funded project told AFP on Sunday.
The 108 participants, aged between 18 and 60, will be tested in three groups and given different dosages. They are all residents of the central city of Wuhan — where the new coronavirus first emerged late last year.
As the COVID-19 pandemic rages and governments step up protection measures, pharmaceutical companies and research labs around the world are working at full tilt.
There are currently no approved vaccines or medication for the new disease, which has killed more than 13,000 people worldwide so far.
The vaccine trial announcements come amid an escalating feud between the US and China over the pandemic, with President Donald Trump enraging Beijing by speaking of the “Chinese virus” .
But the quest is expected to take time — the US candidate vaccine may take another year to 18 months before becoming available.
The World Health Organization says that at least 20 corona virus vaccines are currently in development in the global race for a cure.
The first human trial, by the Boston-based biotech firm Moderna, is already underway.
“Going from not even knowing that this virus was out there, which we then identified it as being a cause of infection in China in January, to have any vaccine that we can actually initiate a clinical trial in about two months is unprecedented,” said Dr Lisa Jackson, the Kaiser Permanente investigator leading the first human trial.
This extraordinary speed is thanks in large part to early Chinese efforts to sequence the genetic material of the virus that caused COVID-19.
China shared that information in early January, allowing researchers around the world to replicate the virus and study how it invades human cells and infects people.
Jennifer Haller was the first person to be injected with the trial vaccine. “Everybody is feeling so helpless right now,” Haller said. “And I realised that there was something that I could do to help, and I’m excited to be here.”
Experts say it could still take about 18 months for any potential vaccine to become available to the general public.
Last week, China also approved the start of clinical trials on a vaccine.