- 1 What are the four vaccines Australia is getting?
- 2 Why mRNA, instead of the proven path of an inactivated virus?
- 3 Does it matter that there will be different types of vaccine?
- 4 How will the vaccine be distributed?
- 5 Who gets it first? Can rich people buy the vaccines?
- 6 What about children, pregnant women and immunocompromised people?
- 7 What if the virus mutates?
- 8 Can the government make people get the vaccine?
- 9 What about international travellers?
- 10 How will vaccinations be recorded?
- 11 Can you get two different vaccines, or choose which one to get?
- 12 How long will protection last?
- 13 How many people need to get the vaccine to stop the virus spreading?
- 14 Why are other countries saying they will have vaccines earlier than Australia?
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Around the world about 200 Covid-19 candidate vaccines are being developed, with more than 40 in human clinical trial stage. The Australian government has agreements to secure four of the most promising vaccines, and will roll them out if they prove to be safe and effective.
All four vaccines require two doses, spaced a few weeks apart. As the pharmaceutical companies behind some vaccine candidates begin releasing results, many questions remain about the next steps towards controlling Covid. Here is what we know. .
What are the four vaccines Australia is getting?
Oxford University/AstraZeneca vaccine: This is a viral vector vaccine, containing a weak or inactivated virus that cannot cause disease. This virus has genetic material from the Covid-19 virus inserted in it. Once the viral vector is inside human cells, the cells make a protein unique to the Covid-19 virus. This triggers the body to begin to build an immune response. If infected with Covid-19, the body will remember how to activate this response and fight the real virus.
Australia has secured 33.8m units of this vaccine. The phase three interim clinical trial results have only been communicated in a press release, so it is hard fully to interpret the results in subgroups, for example in elderly people.
In clinical trials, phase three represents the final stage before the drug is rolled out to the general population, and involves tens of thousands of participants.
Novavax vaccine: This is a classical protein vaccine, and includes harmless pieces of Covid-19. Once vaccinated, the immune system recognises that the proteins don’t belong in the body and begins building antibodies.
If the vaccine proves safe and effective, 40m units will be available in Australia as early as the first half of 2021. Phase one and two clinical trials are being conducted in Australia and the United States. Phase three clinical trials are under way in the UK.
University of Queensland/CSL vaccine: This is also a protein vaccine, and Australia has secured 51m units, which it hopes will be available by mid-2021. Phase one clinical trials in humans began in July in Brisbane, with phase two and three clinical trials to be under way in December.
Pfizer/BioNTech vaccine: This is an mRNA-based vaccine that gives human cells instructions for how to make a a protein unique to Covid-19. The protein is harmless, but the body recognises it should not be there and begins to build an immune response. If infected with the real virus, the body will know how to attack.
The Australian government said 10m units of the vaccine would be available from March. Phase three clinical trial results found 95% of people given the vaccine were protected against the virus, and while the full results have not been made public, they are being provided to regulators.
Why mRNA, instead of the proven path of an inactivated virus?
The study protocol for the Pfizer/BioNtech vaccine states there are benefits to this type of vaccine. “Unlike live attenuated vaccines, RNA vaccines do not carry the risks associated with infection and may be given to people who cannot be administered live virus (eg pregnant women and immunocompromised persons),” it says. However, the vaccine still needs to be tested in these groups.
It would be the first mRNA vaccine to be rolled out to the general public, but there have been clinical trials of mRNA vaccines to treat other diseases since the 1990s. They have the benefit of being easier to mass produce and cheaper. But the instability of mRNA vaccines has meant their study has been limited.
With the arrival of Covid-19 it made sense for different pharmaceutical companies to explore different technologies, in case one type did not work. Vaccine technologies have improved rapidly, allowing scientists to address some of the previous problems with mRNA vaccines, such as degradation during delivery into cells.
The Pfizer/BioNTech mRNA Covid-19 vaccine does need to be stored at minus 70C, but sophisticated eskies with dry ice and remote sensing have been produced to keep it stable in transit.
Does it matter that there will be different types of vaccine?
No, this is not uncommon. Each year there is a variety of types of flu vaccine. High-dose flu vaccines are offered to the elderly, but not routinely to healthy adults.
A taskforce of medical experts will look at the Covid-19 vaccines and decide which should go to which locations or groups of people. Like other common vaccines such as for tetanus and hepatitis A, the four Covid-19 vaccines are delivered with an intramuscular injection.
How will the vaccine be distributed?
The first doses will be rolled out from March.
The program will depend on the nature and test results of the vaccines approved for use, the federal health department has said, and will take into account any current outbreaks. If there was a large outbreak in a particular state, it would make sense to send the vaccine there first.
The physical rollout will be complex due to different storage, transport, security and administration requirements for the vaccine types. The federal government will be responsible for safely transporting vaccine doses to storage and administration sites within each state and territory.
Once vaccine doses are delivered, the states and territories will take responsibility for the safety and storage. Vaccines may be administered in GP clinics, dedicated vaccination clinics and workplaces, and vaccination teams will visit aged care homes and other centres with vulnerable populations.
The Aboriginal and Torres Strait Islander community controlled health sector will help identify rollout locations. Pharmacies are likely to play a role once enough doses are in stock and vulnerable and target populations have been vaccinated. If vaccines are licensed for children, they may be administered in schools.
The federal government said “to achieve wide population coverage it is likely that all or most” of these locations will need to be used over several months.
Who gets it first? Can rich people buy the vaccines?
According to a federal department of health spokeswoman, potential sales are up to the vaccine companies. “The Australian government is committed to providing Covid-19 vaccines at no cost to consumers,” she said. “Decisions to make any vaccine available privately are for the sponsoring company, noting all vaccines need to be registered by the TGA before they can be supplied in Australia.”
The Australian Technical Advisory Group on Immunisation is advising the federal government about which groups should be prioritised for the first free doses. In line with World Health Organization recommendations, ATAGI said the first groups to be vaccinated should be:
Those who have an increased risk of developing severe disease [such as the elderly].
Those at risk of exposure, being infected with and transmitting the virus.
Those working in services critical to society functioning [such as health work and aged care].
Once enough doses are in stock, all Australians who want the vaccine will be given access on a voluntary basis during 2021.
What about children, pregnant women and immunocompromised people?
Clinical trials of new vaccines and drugs are usually first conducted in healthy adults. Once proven safe, they are then sometimes trialled in children, pregnant women, and immunocompromised people. None of the trials with phase three results announced to date have included children, but some between the ages of five and 12 are being recruited as part of phase 2/3 clinical trials being led by Oxford University in the UK.
Pregnant women, and those of childbearing age who were not using contraception, were excluded from the Pfizer/BioNTech and the AstraZeneca/Oxford University trials. Men also had to agree to use contraception and refrain from donating sperm.
If any women nevertheless became pregnant during the trial, they were to be carefully monitored. However, because the full results have not been made public yet, we don’t know if any women became pregnant and, if so, how the vaccine affected them.
AstraZeneca told Guardian Australia it hoped to include pregnant women in the eventual group of people for whom the vaccine is approved.
The Pfizer/ BioNTech study protocol says people with HIV, hepatitis C or hepatitis B were excluded from phase one and two of the trial, and people with any history of autoimmune diseasefrom phase one. It is unclear how many of these people were included in phase three.
The University of Oxford and AstraZeneca trials excluded people if they had any significant disease that might be exacerbated by taking part in the study, or that might impair interpretation of the data.
The Novavax vaccine is being tested during phase three in people living with HIV, and those with other chronic conditions, but full results are not available yet.
Regardless, Australia’s drugs regulator will not approve use of the vaccines in children, pregnant women or immunocompromised people until it has been presented with data and is satisfied about the safety in those groups.
What if the virus mutates?
So far, Covid-19 appears to be a slow-changing virus. A virologist with the University of Queensland, Associate Prof Ian Mackay, said for now Covid-19 and its variants can still be considered as a single virus. That means vaccines are likely to be effective against all variants.
But even if the virus did mutate significantly, it is likely scientists will be able to tweak existing technology to create a new vaccine, rather than having to start from scratch.
Can the government make people get the vaccine?
Vaccines are mandatory in some states for people working with vulnerable people, such as in healthcare. But for the general population, the federal health minister, Greg Hunt, has made it clear that getting the vaccine will be voluntary.
In August, Scott Morrison said he was aiming for 95% uptake of the vaccine. The government will first rely on public health campaigns and making access as easy as possible to achieve this. A survey from the Australian National University published in November found most Australians intended to get the vaccine, even before phase three clinical trial results were available demonstrating safety and efficacy.
A health department spokeswoman said: “We are confident, given Australia’s high vaccination coverage rates, Australians will take up a safe and effective Covid-19 vaccine in equally high numbers.”
What about international travellers?
Qantas has said international air travellers will in future need to prove they have been vaccinated against the virus, and it is likely some governments will require that visitors be vaccinated before allowing them entry. Some countries have long required proof of vaccination against other diseases, such as yellow fever.
The federal government’s vaccination policy states: “While the Australian government strongly supports immunisation and will run a strong campaign to encourage vaccination, it is not mandatory and individuals may choose not to vaccinate. There may however, be circumstances where the Australian government and other governments may introduce border entry or re-entry requirements that are conditional on proof of vaccination.”
How will vaccinations be recorded?
The Australian Immunisation Register is a national system to monitor overall immunisation rates and an individual’s immunisation status. It will be mandatory for vaccination providers to record Covid-19 vaccinations into this system. People can access and download their vaccination history through this register, and can access it with a Medicare online account or through the Express Plus Medicare mobile app.
Can you get two different vaccines, or choose which one to get?
The four vaccines Australia will import and/or manufacture all require two doses. The immunisation register can be monitored so that people won’t be given two different types, and they can be reminded to get their second dose. The effects of receiving two different vaccine types have not been tested.
The first shot helps the body learn to fight the infection, while the second, given three to four weeks later, helps builds protection. It takes the body a few weeks to build immunity, so people will not be protected straight after their first dose, and booster shots may be needed in subsequent years.
Prof Allen Cheng, an infectious diseases doctor on the Covid-19 vaccine advisory group for the Australian government, said: “There won’t be 44m doses all coming on the same day.
“What vaccine you get will depend on when they arrive, what group of people you’re in … But one thing to know is you can’t mix and match the two doses.”
People are unlikely to be given a choice of which vaccine they get, at least in the early stages of rollout. This is no different to flu.
How long will protection last?
We don’t know. To truly know the effectiveness of a vaccine, it needs to be monitored once it has been rolled out in the general population. Effectiveness is determined in the real world, not in clinical trials.
While the vaccines have ranged in their efficacy in clinical trials, the head of the biosecurity program at the Kirby Institute at the University of NSW, Prof Raina MacIntyre, says: “The more important question is, what is the efficacy at 12 months, 24 months and 36 months?
“Further, we do need to see the results of the phase three trials published in the peer-reviewed literature before making valid comparisons,” she said.
Based on the preliminary, non-peer reviewed data, all three vaccines with their optimal dosing are more than 90% efficacious, which MacIntyre describes as “great news”. But she urges caution.
“At the most, the only available data at this stage would be efficacy at one-to-three months post-dose one, and no trial would have data beyond six months post-vaccination, because the earliest phase three trials commenced in April.”
How many people need to get the vaccine to stop the virus spreading?
We don’t know if the vaccines stop spread, Cheng says. “The end point in the trials done so far was to look at: did people get sick?” he said. “The vaccines stopped people getting sick, but we don’t know whether they perhaps had a very mild infection without symptoms that could still be spread. There are animal vaccines for other coronaviruses that protect against disease, but not infection. If that’s the case then it will be very important for people to be vaccinated.”
Why are other countries saying they will have vaccines earlier than Australia?
Hunt has said Australia may not get its first vaccines until March, but the UK is hoping to have most of its population vaccinated by Easter.
Cheng says no country is likely to approve the vaccine until regulators have looked at all of the data, despite any claims they may be making now.
“Regulators like the TGA look at more than just a published study,” Cheng says. “I’ve looked at TGA dossiers of more than 100,000 pages and they contain so much data. One of the differences in the UK and US is they are balancing up this data with a real, live epidemic going on. We don’t have any cases. There is more of an urgency to get the data and roll it out there.”
The manufacturing capabilities of different countries would also be a factor, Cheng says.
But the World Health Organization and G20 countries have committed to ensuring fair and equitable access to the vaccine throughout 2021.
Source: The Guardian
Keyword: Australia’s Covid vaccines: everything you need to know | Health