Scientists in Thailand are testing a coronavirus vaccine on monkeys following successful trials of the formula on mice.
Sky News has been given exclusive access to the COVID-19 vaccine research programme at Chulalongkorn University in Bangkok.
The so-called mRNA jab is a type of vaccination that has never been approved for public use before.
It uses molecules called messenger RNA (mRNA) that prompt the body to make its own defences.
Essentially, a snippet of coronavirus‘ genetic code is injected into a human stimulating a process which sparks an immune response to help it to fight the infection.
“When you inject humans, the vaccine will be taken up by the cell, the cell starts making protein which is a small piece of that virus. That will start to induce your immune system to be ready to produce an immune response against a future infection of the virus,” explained Professor Kiat Ruxrungtham, director of the COVID-19 vaccine research programme.
Researchers say it is quicker and cheaper to develop than traditional vaccines, potentially opening up new affordable options for some developing countries if the government-backed programme is successful.
Sky News was the only broadcaster invited to witness scientists preparing the vaccine ahead of the trial.
The team at Thailand’s National Primate Research Center filled 13 syringes with three mixtures.
They were then put into a hatch where they were collected by a waiting vet.
Each Cynomolgus macaque will receive one dose once a month for the next three months.
Researchers will monitor the safety and immune response.
Trials have already been successfully completed in mice.
When COVID-19 attacks our bodies it binds to receptors in our lungs.
Scientists said the tests are carried out on monkeys because they are genetically closest to humans.
“Only monkeys have the ACE2 receptor that can bind with that virus so that’s why you need monkeys to test it before you go up to humans,” said Professor Suchinda Malaivijitnond, director of the National Primate Research Center of Thailand, Chulalongkorn University.
Some of the monkeys at the research centre are housed in a breeding colony.
They aren’t involved in the trial.
Inside the macaques generally live in groups as they are naturally sociable.
The cages have been fitted with swings and baths of water which Professor Malaivijitnond explained were provided because macaques like to swim.
Vaccines usually take an average of 10 years to develop.
While COVID-19 has forced scientists to try to create one in 12 to 18 months, regulators still want proof the jabs are safe for widespread use in humans and that traditionally requires data from animal trials.
More than 150 COVID-19 candidate vaccines are in development worldwide, with around eight now conducting human tests.
Projects in the UK and China have already completed tests on monkeys.
Moderna, the developers of a different mRNA coronavirus vaccination in the US, fast-tracked their trial to test the experimental drug on humans but also reviewed studies on mice.
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Some international campaign groups question if animal testing is necessary or provides reliable results.
Scientists in Thailand said they limit the number involved.
“I would say if it’s not necessary, don’t do it in monkeys,” explained Professor Malaivijitnond.
“With this one (COVID-19) we have no choice that’s why we do it in monkeys because with the COVID-19 virus only monkeys respond in a similar way to humans and also you can see we use very few monkeys in each testing group.”
If the trials are successful, researchers hope to start tests on humans next year, with plans to have a vaccine ready for release by the end of 2021.
Thailand could also produce it for seven other countries in Southeast and South Asia, meaning nations which may not have the capabilities to develop their own vaccination are able to protect their populations at a lower cost.
“Our goal is that hopefully Thai people can get access to a vaccine as soon as most big countries get it, so that’s why we have to work hard,” said Prof Ruxrungtham.