From an interesting review in the BMJ:
COVID-19, what do we know so far about a vaccine.
The World Health Organisation announced that there are 83 potential COVID-19 vaccines being assessed.
7 are now approved for human testing through clinical trials.
So, what do we know about these 7 approved candidates?
There appears to be a geographical distribution between Asia, Europe and America, so for the purpose of this review, we will list the vaccine companies by country.
Three are being tested in Beijing.
CanSino Biological, a company based in Beijing in collaboration with the Beijing Institute of Biotechnology has the only vaccine in a phase 2 trial.
Although the move to a phase 2 trial is a good sign, this company has never then published results of the phase 1 trial which looked at adverse reactions seven days after the injection.
In their phase two trial they are testing 375 healthy adults with 125 people in the control group and will look at adverse reactions within 14 days and also they will measure the levels of COVID-19 neutralising antibodies and of antibodies against the coronavirus spike protein at day 28. They will also follow up participants at six months.
Sinovac. This Beijing-based company is currently testing its inactivated virus COVID-19 vaccine in a randomised double blinded placebo controlled phase 1 trial involving 144 adults. Astonishingly, in a pre-print concerning the vaccines effectiveness in mice, rats and non-human primates, they state it conferred a complete protection against the SARS-CoV-2 strains circulating worldwide.
The company is planning to test the vaccine on another 600 people during the phase 2 trial.
The Beijing Institute of Biological Products and The Wuhan Institute of Biological Products is also producing a vaccine but there is little information about this available.
The researchers at the University of Oxford are testing their vaccine which uses an adenovirus vaccine vector and the SARS-CoV-2 spike protein on 1102 healthy volunteers.
Interestingly, they are using the meningitis ACWY vaccine as a control instead of saline solution. They argue that using this they expect to see minor side effects such as sore arm, headache and fever in the COVID-19 vaccine group that would not develop in the saline group and therefore they can compare these with the meningitis ACWY vaccine.
Moderna. This company has developed a vaccine called the mRNA-1273 with the National Institute of Allergy and Infectious Diseases.
Their first patients were injected in March and the trial has now been expanded to include 60 adults, which will hopefully help to examine the vaccine’s safety.
The vaccine is being given in two doses with the second injection at 28 days after the first.
If the trial is successful, the vaccine will move to a phase 2 trial where its effectiveness against COVID-19 will be tested.
Inovio Pharmaceuticals. This is a company based in Pennsylvania and began testing its DNA platform vaccine in April. Their chief executive officer Mr Joseph Kim told CNBC that he thought it would be possible to meet a 12 to 18 month timeline for the COVID-19 vaccine. He felt that this was possible because they had a platform that was safe and they had tested similar approaches before against other pathogens.
BioNTech, a German biotech company has developed a vaccine programme which has also been approved but is yet to start. They have partnered with Pfizer and it involves four potential vaccines which are initially to be tested in Germany on 200 healthy participants.
They plan to include people with a higher risk for severe COVID-19 at the second stage of testing. Their vaccines represent different mRNA formats and target antigens.
They have collaborated with a Chinese drug company Fosun Pharma to conduct trials in China and are also planning trials in the United States pending regulatory approval.
So how difficult is it to create a COVID-19 vaccine?
Robin Shattock, The Lead of the COVID-19 vaccine trial at Imperial College London, which is beginning in June said that developing a vaccine should be relatively easy because unlike influenza and HIV, the COVID-19 virus seems to be relatively stable.
He said on the BBC’s today programme on 22 April, we are very confident that some vaccines will come through and work. There are so many teams working on different approaches, and this virus is not as difficult a target as some of the things we have seen before. So, scientifically it suggests that there is a very high chance of success of getting a vaccine.
How long does it usually take to develop a vaccine?
Vaccine development takes a long time, normally more than 10 years and costs hundreds of millions of pounds.
Clinical trials normally begin around two to five years after the initial research into the immune response and involve testing in thousands of people. Following this, there is another two years of preclinical trials involving animal testing.
If the vaccine is found to be safe and effective, it then has to pass through the regulatory requirements of its country and worldwide in order to gain approval. Once this is completed there is then the process to manufacture and deliver a vaccine. This can be expensive and complex, requiring specialist highly regulated facilities.
In this current crisis a new 12 to 18 months timeframe has been proposed. This involves teams around the world working with increasing speed. It can be imagined that this requires huge sums of money in order to fund a wide variety of candidates and approaches. The regulators, vaccine innovators, researchers and scientists must be commended if they are able to achieve an effective vaccine within this time frame.
What happens if a successful vaccine is found?
Welcome have stated that global manufacturing capacity will have to be built if a vaccine needs to be rolled out worldwide requiring billions of dollars.
The foundation has said that new manufacturing sites should be built before clinical trials are completed to ensure that production can begin as soon as the vaccine is approved. They also emphasised that these sites should be distributed around the world in order to ensure an equitable distribution.
Are countries collaborating?
The WHO has brought together world leaders and health partners including those from the private sector in an initiative aimed at accelerating the development and production of a new COVID-19 vaccine. This hopefully would enable tests and treatments to be equal across the world.
Could a vaccine end the pandemic?
There is a degree of scepticism about this. The WHO has repeatedly warned countries against relying on a vaccine to end the current situation. They state that we need to think of ourselves in a position of a new norm until such a time that a vaccine might be available. Ohid Yaqub, Senior Lecturer at the University of Sussex’s Science Policy Research Unit has also warned that there is a long history of over optimistic vaccine predictions and even if a vaccine became available, it was too early even to speculate whether it will have a high efficacy or low efficacy. He added, “I therefore think public policy attention should continue to focus on testing and on healthcare system capacity, and it should focus on lockdown and managing the social costs of partial lockdown for as long as possible.”
We at The London General Practice still commend all our NHS workers, researchers, scientists and those working in the field and await with anticipation an effective vaccine.
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