Could the race for a coronavirus vaccine be nearing the line?
We are inching closer to finding a medical solution to the global Covid nightmare, driven by money and the desire to achieve political kudos.
Back in the 1960s, it was the Space Race that saw the world’s largest powers battle it out for international supremacy.
Today, it looks as if those old rivalries are resumed as the US, UK and Germany are locked in a battle with Russia and China to see who can be first to develop a vaccine for the coronavirus.
It is a race in which Russia has already declared itself the victor, having approved its vaccine for general use last month.
However, respected medical journal The Lancet has said the claim is premature, saying that there is insufficient evidence that the virus works, or that it is even safe to administer.
A total of 167 potential vaccines are in development at the moment.
Most of are in preclinical stages, meaning they are still being tested on animals or in the lab, but 26 have reached human trials.
Of these, only a handful have reached ‘phase three’ testing, normally the final stage before regulatory approval is granted or denied.
Clinical trials are broken up into three or four stages, with the earlier ones, known as phase one and phase two, looking at safety, dosage, possible side effects and effectiveness in fighting the pathogen.
But it is the phase three trials, which see them tested on hundreds or even thousands of human volunteers, which usually determine whether a vaccine is approved.
Here are the most promising vaccines:
Oxford University/AstraZeneca
This vaccine is made from a weakened version of a common cold virus, called an adenovirus, that infects chimpanzees. Researchers genetically altered the virus so that it couldn’t replicate in humans and added genes to code for the so-called spike proteins that the coronavirus uses to infect human cells.
In theory, the vaccine will teach the body to recognize these spikes, so that when a person is exposed, the immune system can destroy the virus.
In April, researchers began testing the vaccine on people and published early results from their phase one and still-ongoing phase two trials on July 20 in the journal The Lancet.
The vaccine didn’t cause any serious adverse effects in participants but did prompt some mild side effects, such as muscle ache and chills.
The vaccine spurred the immune system to produce Covid-specific T-cells.
These are a group of white blood cells important in the fight against pathogens — and neutralising antibodies, or molecules that can latch onto the virus and block it from infecting cells, according to the report.
Phase three trials began in June, on up to 5,000 volunteers in Brazil. Another phase three trial is expected to enrol an additional 10,500 people in the UK and 30,000 in the U.S.
The team at Oxford has also expressed interest in conducting challenge studies on humans, meaning they would deliberately infect low-risk volunteers with the virus, either alongside phase three trials or after they are complete.
Enrolment on the trials was halted on September 8 after one of the people taking part developed a neurological problem, but resumed on September 12 after the trials were declared safe.
The UK government has provided £84.1 million funding for the research, while the US Department of Health and Human Services announced that it would give up to $1.2 billion to AstraZeneca to accelerate the vaccine development process and to help the company manufacture at least 300 million doses of the vaccine — if it proves safe and effective — as early as next month, according to a statement.
Sinovac Biotech
This vaccine, developed by Beijing-based Sinovac Biotech, protected rhesus macaque monkeys from infection with the novel coronavirus, according to a study published in July. The company, having already shown the vaccine to be safe and effective in early clinical trials, was last month recruiting for a phase three clinical trial with 8,870 participants in Brazil.
Unlike the Oxford vaccine, which uses a weakened version of a live virus, this vaccine is made from an ‘inactivated’ or dead version of the pathogen that causes the disease.
The advantage of the an inactivated virus is that the risks are lower for people with weakened immune systems or other health problems, but the disadvantage is that they are typically not as protective as live vaccines and might require booster shots over time.
Sinovac began phase one and two trials on 743 healthy adults in April, and reported that the vaccine didn’t cause any serious adverse events. Study authors also said more than 90 per cent of participants had developed neutralising antibodies to the vaccine two weeks after receiving a second dose. However, their results have only been reported in a press release and haven’t yet been published in a peer-reviewed journal.
Moderna
Developed by American biotech company Moderna and the US National Institute of Allergy and Infectious Diseases (NIAID), this was the first vaccine to be tested on humans in the US.
Moderna’s vaccine relies on a technology that hasn’t been used in any approved vaccines before,
While traditional vaccines are made up of weakened or inactive viruses, or proteins of those viruses, to trigger an immune response, this vaccine is made from a genetic material called mRNA that teaches cells to build these viral proteins themselves, in this case, the coronavirus’s spike protein.
This technology makes the vaccines quicker and easier to manufacture, as they do not require scientists to grow and inactivate entire pathogens or their proteins. It is also possible that they might work better against pathogens that tend to mutate, such as coronaviruses and flu viruses.
There are disadvantages though: mRNA vaccines can cause adverse reactions in the body, and also break down more quickly, limiting the strength of immunity..
On July 14, Moderna published promising early results from a phase one trial consisting of 45 participants in The New England Journal of Medicine. Participants were divided into three groups and given a low, medium or high dose of the vaccine. After receiving two doses of the vaccine, all participants developed neutralising antibodies at levels above the average of those found in recovered Covid-19 patients.
The vaccine appeared safe and generally well-tolerated, but more than half of the participants had some side effects including fatigue, chills, headache, muscle aches and pain at the injection site. These are similar to the side effects experienced with the winter flu jab.
The company began its phase three trial on July 27, which is expected to involve 30,000 people. The first results from the trial could be available by November.
CanSino Biologics
Chinese CanSino Biologics, in collaboration with the Beijing Institute of Biotechnology, developed a candidate vaccine using a weakened cold virus.
Unlike the Oxford vaccine, which relies on a virus that infects chimpanzees, CanSino Biologics is using an adenovirus that infects humans.
Along with Moderna, this group also published results from its phase two trial on July 20 in The Lancet.
The trial, conducted in Wuhan, where the first coronavirus cases emerged, involved 508 people randomly assigned to receive either one of two different doses of the vaccine or a placebo
The tests found no serious adverse effects, although some reported mild or moderate reactions including fever, fatigue and injection site pain.
About 90 per cent of the participants developed T-cell responses and about 85 per cent developed neutralizing antibodies, according to the study.
A review in The Lancet said both the CanSino and Oxford vaccines looked encouraging.
“Overall, the results of both trials are broadly similar and promising,” it reported.
It raises the prospect of mass production of both vaccines relatively early, allowing millions across the world access to immunisation.
Sinopharm
The state-owned China National Pharmaceutical Group (Sinopharm) vaccine is an inactivated form of the coronavirus.
On August 13, the company published data from its phase one and phase two clinical trials in the Journal of the American Medical Association (Jama).
In the phase one trial, 96 healthy adults were randomly assigned to receive either a low, medium or high dose of the vaccine or to receive aluminium hydroxide as a placebo. They were given second and third doses of the vaccine – or the placebo – after four and eight weeks respectively. The researchers found that the vaccine triggered their bodies to produce neutralising antibodies. Among those who received the placebo, 12.5 per cent had adverse reactions. In those who received low, medium and high dose vaccines, 20.8 per cent, 16.7 per cent and 25 per cent had mild adverse reactions, respectively, according to the study.
In the phase two trial, 224 adults were given a medium dose or a placebo and then a second shot either 14 days or 21 days after the first. Again, the participants developed neutralising antibodies and reported some mild adverse reactions.
The company began its phase three trial in Abu Dhabi, which will recruit up to 15,000 people. The participants will receive one of two vaccine strains or a placebo, according to reports.
Pfizer/BioNTech/Fosun
This is a truly global partnership, between US pharmaceutical giant Pfizer, German biotech company BioNTech, and Chinese conglomerate Fosun – part of the conglomerate that owns Wolves.
Like the Moderna vaccine, this makes use of mRNA technology which prompts the immune system to recognise the virus.
Early phase 1 and phase 2 tests found that the vaccine didn’t cause any serious adverse events and could spur an immune response.
The researchers found antibody levels at 1.8 to 2.8 times higher than those found in recovered patients, according to the study. Later, Pfizer announced new results that the vaccine also prompted the production of T-cells specific to the novel coronavirus.
The UK Government has signed an agreement with Pfizer and BioNTech for 30 million doses of the vaccine subject to it being approved, and the American Government has also struck a $1.95 billion contract with the company to produce at least 100 million doses of the vaccine by the end of the year if it proves to be safe and effective.
The consortium is hoping to be ready for a regulatory review by the end of October. It published an optimistic update this week.
Janssen
Johnson & Johnson’s Janssen experimental vaccine is being developed from a weakened cold virus, which is used to spur the immune response.
In this case, the weakened a cold virus expresses the Covid ‘spike’ protein.
Researchers reported on July 30 that a single shot of the vaccine protected rhesus macaques from infection.
In this study, the scientists tested seven slightly varied prototypes of the vaccine, and identified the one that produced the highest number of neutralising antibodies.
After receiving the chosen variant, the monkeys were then exposed to the coronavirus.
Six out of seven monkeys that were given the vaccine, and then exposed to the coronavirus, showed no detectable infection in the lower respiratory tract, although one showed very low levels in its nose.
Phase three trials are due to begin this month with an estimated 60,000 participants across the globe.
This trial is being followed closely in America.
Johnson & Johnson recently announced a $1 billion agreement with the US Government to deliver 100 million doses of the vaccine if it receives approval or emergency use authorisation.
Sputnik V
Vladimir Putin shocked the world last month when he announced that the Russian Government had approved use of the Sputnik V vaccine, and started making it available to the general public.
Mr Putin sees it as a matter of national honour to be the first to release a vaccine.
But while the Russian Government has declared the drug safe, scientists around the world have voiced concerns about it being released to the public before phase three tests have been carried out.
The vaccine, created by the Gamaleya Research Institute of Epidemiology and Microbiology, makes use of a common cold virus to produced an immune response.
A group of 15 scientists sent a formal letter to The Lancet this week outlining doubts about the accuracy of data in the phase one and two trials.
Peter Drobac, infectious disease medic at Oxford University, voiced concerns that the vaccine had been rushed through, before it had been properly tested.
“We have no idea that the claims that are being made about the safety and immune response of this virus are true or not,” he said.
“Geopolitics – being able to claim victory – may put pressure on other countries to cut corners on safety and effectiveness as well. That could put all in danger”.
The World Health Organisation said: “Prequalification of any vaccine includes the rigorous review and assessment of all required safety and efficacy data.
“You cannot use a vaccine or drugs or medicines without following through all of these stages, having complied with all of these stages.”
However, some countries have expressed an interest in trialling the vaccine.
The Philippines plans to start trialling the vaccine in October, with President Rodrigo Duterte expected to be inoculated as early as May next year.
Meanwhile the Brazilian technology institute said it expected to start by the second half of 2021, shortly after the state of Parana signed a memorandum of understanding with Moscow.
