PERTH, Australia – Australia’s Therapeutic Goods Administration (TGA) has granted provisional approval to Astrazeneca Pty Ltd. for its COVID-19 vaccine, a recombinant adenovirus vaccine, making it the second COVID-19 vaccine to receive regulatory approval in Australia, following the Jan. 26 provisional approval for Pfizer Australia Pty Ltd.’s COVID-19 vaccine, branded Comirnaty.
“Astrazeneca is cleared for lift-off,” said Health Minister Greg Hunt. “What I can say is that the TGA has approved the Astrazeneca vaccine for use in Australia on the basis of all ages and a second dose at 12 weeks. They have taken the best advice from around the world. They have also had the opportunity to examine the advice and real-world evidence gathered from the emergency use provisions in other countries.”
The provisional approval of the Astrazeneca COVID-19 vaccine means that it is now approved and included in the Australian Register of Therapeutic Goods (ARTG). The TGA is the second regulator to grant the vaccine provisional approval, as others have granted it emergency authorization, said TGA Head John Skerritt during a Feb. 16 press conference.
The AZ vaccine is indicated for immunization of people 18 and older for prevention of COVID-19 caused by SARS-CoV-2. Like the Pfizer vaccine, the Astrazeneca vaccine will be given in two separate doses. The TGA recommends that the second dose be administered from four to 12 weeks after the first dose. The Australian Technical Advisory Group on Immunization recommended that the interval between the first and second dose be 12 weeks.
Provisional approval of the vaccine is valid for two years, and it is subject to certain conditions, such as requiring Astrazeneca to continue providing information to the TGA on longer-term efficacy and safety from ongoing clinical trials and postmarket assessments.
Elderly patients over 65 demonstrated a strong immune response to the vaccine in clinical trials, but there was an insufficient number of patients infected by COVID-19 to conclusively determine the efficacy in that subgroup, the TGA said. Efficacy has “been inferred” from immunogenicity data and efficacy demonstrated in the general population, the agency said.
There were no safety concerns in this age group in clinical trials, nor in the large numbers of elderly people who have been vaccinated to date in overseas rollouts, the TGA said, adding that the decision to immunize an elderly patient should be decided on a case-by-case basis with consideration of age, co-morbidities and their environment, taking into account the “benefits of vaccination and potential risks.”
“Our approval of this vaccine does not have an upper age limit,” Skerritt stressed. “While the data for this vaccine in older groups is limited, and that goes back to the original design of the trials, where Astrazeneca targeted their initial trials towards health care workers who obviously are of working age and usually under 65, and only included older people later on.
“But our analysis of the data gives us no reason to suspect that the vaccine would not be fully efficacious in older groups.”
The U.K. has been vaccinating with the Astrazeneca vaccine for more than a month, Skerritt said, and rollout there has been targeted toward front-line health workers as well as aged care facilities.
“Moreover, a recently released preprint in review for The Lancet shows 76% efficacy after one jab, increasing to 82% after a booster jab given three months later,” said Magdalena Plebanski, head of the Translational Immunology and Nanotechnology program in the school of Health and Biomedical Science at RMIT University in Melbourne.
“Excitingly, new data is also shown that the vaccine eliminates the virus itself on top of disease symptoms, opening the possibility that vaccination could both prevent disease and become a transmission breaking tool," she said.
Local manufacturer CSL will run 24/7 production
Initial supply of the vaccine will be imported into Australia from overseas; however, ongoing supply will be manufactured in Australia by CSL. The company has a contract to manufacture 50 million doses of the AZ vaccine and is on track to deliver the first doses in March.
Prior to supply of vaccines manufactured onshore, Astrazeneca will submit further information and data to the TGA to confirm that onshore manufacturing meets strict good manufacturing practices (GMP) quality standards.
"The advantages of this vaccine for Australia include its ease of production, with CSL able to produce downstream large quantities locally, as well as distribution and storage at conventional fridge temperatures,” Plebanski added.
Since late last year, CSL Behring’s advanced manufacturing facility in Broadmeadows, Victoria, began local manufacture of the Astrazeneca vaccine. That process employs 2,000-liter bioreactors in which a host cell line is expanded and then used to produce the adenovirus-based vaccine developed by the University of Oxford. The vaccine is then purified and stored in preparation for the next stage of the process.
Early next week, the final manufacturing phase will begin at CSL’s Seqirus facility in Parkville, Victoria, where the vaccine is formulated to a precise concentration, before being filtered and filled into vials. At the same time, each batch of finished vaccine will undergo an extensive quality check process by CSL, by Astrazeneca and by the TGA.
Seqirus fill and finish will continue to run 24 hours a day, seven days a week, with expected release of 2 million doses at the end of March, and then 1 million doses per week thereafter, CSL said during a Feb. 16 media briefing.
“While the work isn’t over, we are incredibly proud to be on the cusp of delivering a locally made vaccine for Australians,” said Andrew Nash, CSL’s chief scientific officer. “Some of the most critical work is still to come – in particular, extensive quality checks that will be behind every finished vaccine."
Hassan Vally, an expert in epidemiology and associate professor at La Trobe University in Melbourne, said the advantages of the Astrazeneca vaccine are the local production capability and storage at normal room temperatures.
Although there is ongoing concern about what effect the new variants will have on all of the vaccines that have been made based on the original Wuhan variant of the virus, CSL has indicated that it is confident it will be able to update the vaccine if required, he said.
Pfizer vaccine begins rollout
Just a day before the Astrazeneca vaccine was approved, Health Minister Hunt announced that more than 142,000 doses of the Pfizer COVID-19 vaccine arrived in Australia, marking the first shipment of 20 million doses the government has secured. The TGA will batch test the vaccines to ensure they meet quality standards.
Prime Minister Scott Morrison said the country was on track for the first and most vulnerable Australians to start receiving the vaccine beginning Feb. 22.
“The vaccine has landed and we’re stepping up our fight against the pandemic,” Morrison said.
Roughly 80,000 doses of the Pfizer vaccine will be released in the first week, and 50,000 vaccines will be made available for the states and territories for hotel quarantine and border workers and frontline health care workers. Roughly 30,000 vaccines will be made available for aged care and disability care residents.
The vaccine will be delivered through hospital hubs across Australia, and in residential aged care and disability care facilities. Logistics company DHL has been engaged to support the distribution of the Pfizer vaccine across Australia.
The company, along with a network of 200 ultra-low temperature portable freezers, will ensure Australians across the country, including in rural and remote areas, are able to access the Pfizer vaccine, which needs to be stored at minus 70 degrees.