Pros and cons of each vaccine Australians could get
With a growing list of countries rapdily vaccinting their populations against coronavirus, there is mounting pressure on the Australian government to follow in its footsteps.
The Federal Govenrment has contracts in place for three different coronavirus vaccines, though the approval process is expected to take considerably longer than it has in the United Kingdom and United States.
The earliest approvals from Australia’s Therapeutic Goods Administration are expected by the end of January 2021, with doses then likely to be rolled out around March.
Here is a look at the pros and cons of each of the vaccine candidates that could be available to Australians next year.
The Pfizer/BioNTech is probably the vaccine most people have heard about as it is the one being used by the UK government.
The vaccine is being developed by US pharmaceutical company Pfizer and German biotechnology company BioNTech.
This candidate is an mRNA-based vaccine which has never been approved before.
Up to now vaccines have been developed using a weak or dead version of a virus, or by using a laboratory-made protein.
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But mRNA vaccines can be created entirely by scientists in a laboratory using chemicals, enzymes, bacteria or live cells.
Essentially the scientists make a synthetic version of the virus’s messenger ribonucleic acid (mRNA). Once this is injected into the body, the mRNA prompts the body to make a particular protein, which is detected by the immune system and this causes the immune system to make antibodies to fight against it.
Australia has ordered 10 million doses of the vaccine which will be manufactured off shore if the candidate is approved.
Recipients will need to get two doses of the vaccine 21 days apart. Pfizer and BioNTech are reportedly charging buyers $US19.50 ($A26.30) per dose.
• The vaccine was found to be 95 per cent effective in protecting against COVID-19 in Phase 3 clinical trials. Of the 43,000 people in the trial only eight people in the vaccine group developed coronavirus, compared to 162 into the placebo group.
• It was also found to be more than 94 per cent effective in people over the age of 65.
• There have been minimal adverse reactions, with a small amount of participants experiencing fatigue and headaches after receiving the jab.
• It must be stored at -70C. This means that an unbroken ‘cold chain’ must be maintained from the time the vaccine comes off the production line to the time when it is administered.
• This leaves the Australian government with three options: keeping doses in ultra-low freezers where they can last up to six months, keeping doses in eskies where they can last up to 15 days or storing doses in a regular fridge where they can last up to five days.
UNIVERSITY OF OXFORD/ASTRAZENECA
This vaccine being developed by University of Oxford and pharmaceutical and biopharmaceutical company AstraZeneca.
It is a viral vector vaccine which means it uses a weakened version of the virus, which is incapable of causing disease itself, to deliver an antigen into the body.
If this vaccine is successful 3.8 million doses will be delivered to Australia in early 2021. 50 million doses will be manufactured in Australia between from early 2021 in monthly batches through to September 2021.
The vaccine is expected to be around $A4 a dose.
• The vaccine was shown to be 90 per cent effective when given as a half dose followed by a full dose a month later.
• It is significantly cheaper per dose than the other candidates.
• Can be stored between 2C to 8C for at least six months, allowing for easier manufacturing, distribution and storage.
• No serious safety events relating to the vaccine were observed during Phase 3 trials, with the shot “well tolerated” across different dosing regimens.
• When given two full doses a month a part the vaccine showed a lower efficacy rate of 62 per cent, which is significantly lower than some of the other candidates.
• It was revealed the people that received the half-dose of the vaccine were all younger than 55, which raised concerns the 90 per cent efficacy for that dosage group may be skewed.
This vaccine candidate is being created by American vaccine development company Novavax.
Like the University of Queensland/CSL candidate, this is a protein vaccine.
Australia has ordered 51 million doses to be made available in 2021 if the vaccine is approved.
The Novavax vaccine is expected to be about $US16 (A$21.60) per dose.
• Early clinical trials have shown the vaccine is generally well tolerated and can provide strong antibody responses.
• It only needs to be stored at refrigerator temperatures.
• Results from its late stage clinical trials aren’t expected until early 2021, meaning exact percentages of the vaccine’s effectiveness have not yet been released.
• It is expected to be a lot more expensive per dose than the Oxford/AstraZeneca vaccine, though it will still be cheaper than the Pfizer/BioNTech candidate.
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UNIVERSITY OF QUEENSLAND/CSL
The Australian government also had an agreement to use the vaccine being developed by the University of Queensland and biotechnology company CSL.
This agreement was ended after Phase One trials showed participants were returning false positives for HIV as a result of the vaccine.
Follow up tests confirmed there was no HIV virus present and there was no possibility of the vaccine causing the infection, the decision was made not to go forward with the trials over concerns people may decrease confidence in other vaccine candidates.
University of Queensland researchers said they were “devastated” by the outcome.
“I think there’s probably a single word that sums it up, it’s devastated,” Professor Paul Young said.
“The last 24 hours or so have been particularly difficult. The last 11 months we’ve been living and breathing this project … it’s challenging times, but that’s science.”
Prime Minister Scott Morrison said at “no point” did the government expect all of its vaccine candidates to be successful, which is why it entered into different agreements.