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14 August, 2021

New vaccine technology is decades old

ACCORDING to the World Health Organisation, there are over 200 vaccine candidates for COVID-19 being developed. “Of all the vaccines that are studied in the lab and laboratory animals, roughly seven out of every 100 will be considered good enough to move into clinical trials in humans.

By David Lornie

Of the vaccines that do make it to clinical trials, just one in five is successful,” the WHO said. The Australian Therapeutic Goods Administration (TGA) is the government body tasked with approving vaccines for public use in this country. 

Vaccines must meet strict standards. Before a vaccine is registered for use, it is tested extensively during development and then in thousands of people. Testing first begins with laboratory research, then animal studies and finally human clinical trials. 

Clinical trials involve testing the vaccine in volunteers, and are conducted in phases. The TGA has currently approved three vaccines for use in Australia, the Pfizer/BioNTech vaccine and the Oxford/Astrazeneca vaccine which have been in use for some time. 

The Moderna vaccination has also just been approved by the TGA. The Pfizer/BioNTech and Moderna vaccines use a technology which packs messenger RNA (mRNA) inside tiny fat droplets which instruct cells how to make the spike protein. 

Unlike vaccine approaches that use either a weakened or dead whole microbe or parts of one, this type of vaccine just uses a section of genetic material that provides the instructions for specific proteins, not the whole microbe. 

DNA and RNA are the instructions our cells use to make proteins. These vaccines deliver a specific set of instructions to our cells, either as DNA or mRNA, for them to make the specific protein that we want our immune system to recognise and respond to. Before the COVID-19 pandemic, none of the nucleic acid vaccines had yet been through the full approvals process for use in humans, though some DNA vaccines, including for particular cancers, were undergoing human trials.

The US Centre for Disease Control said researchers have been studying and working with mRNA vaccines for decades. “Interest has grown in these vaccines because they can be developed in a laboratory using readily available materials. This means the process can be standardised and scaled up, making vaccine development faster than traditional methods of making vaccines,” they said. 

“Because of the pandemic, research in this area has progressed very fast and some mRNA vaccines for COVID-19 are getting emergency use authorisation, which means they can now be given to people beyond using them only in clinical trials.”

 According to the WHO, The mRNA vaccine technology has been studied for over a decade, including in the development of vaccines for Zika, rabies and influenza. “These mRNA vaccines have been rigorously assessed for safety, and clinical trials have shown that they provide a long-lasting immune response.

 mRNA vaccines are notlive virus vaccines and do not interfere with human DNA,” the WHO said. The mRNA molecule is incredibly unstable — it’s so easy to break down it needs to be transported in super-cold conditions. 

 It has no ability to integrate into DNA, so there’s no risk of ‘end of times’ human mutations occuring. Unlike the Pfizer-BioNTech and Moderna vaccines, which store the instructions in single-stranded RNA, the AstraZeneca vaccine uses double-stranded DNA delivered in an engineered virus.

 These viruses have been further crippled by deleting chunks of their genome so that they cannot replicate, further increasing their safety. Like all medicines, the vaccines can have side effects. The TGA said, “The overwhelming majority of these are mild and resolve within a few days. 

The Therapeutic Goods Administration closely monitors suspected side effects. Importantly, adverse events reported to the TGA are often not caused by the vaccine itself”. Possible side effects of a jab are tiredness, headache, muscle pain, chills, fever and nausea.

 Other rare side effects have been noted. “We are closely monitoring rare reports of blood clots with low blood platelets following the AstraZeneca vaccine,” the TGA said. The TGA is also closely monitoring reports of myocarditis and pericarditis following the Pfizer vaccine.

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