Clinical immunologist Dr Anthony Jordan gives advice on how to stay Covid safe this summer, while also enjoying the holidays after a 'rough three years'. Video / NZ Herald
A homegrown Covid-19 booster has entered the final stages of preclinical development – and the scientists behind it are still hopeful Kiwis will get to use it.
Dubbed VAANZ-201, the vaccine is the result of nearly three years of groundwork by an alliance of experts from New Zealand universities, research institutes and bio-tech companies.
It’s now been shown to produce a long-lasting immune response against all coronavirus variants, and is able to be stored at refrigerator temperature for months – offering potential advantages over the Pfizer shot that most Kiwis have received.
The 2020 launch of Vaccine Alliance Aotearoa – Ohu Kaupare Huaketo (VAANZ) came before any other country had produced a vaccine against the virus.
At that point, it wasn’t clear whether a Covid-19 vaccine was even possible, or whether New Zealand would get access to one that could be produced.
“New Zealand’s small population means we don’t have a lot of negotiating power with big pharmaceutical companies who are drawn towards larger and more profitable markets,” VAANZ executive director Dr Kjesten Wiig said.
“The Government wanted to ensure that New Zealand had options in terms of protecting ourselves and our vulnerable populations against Covid-19.”
In May that year, Cabinet ministers announced a $37 million vaccine strategy, with $10m earmarked for local research and development.
Dr Theresa Pankhurst, of the Wellington-based Malaghan Institute for Medical Research, is among a team of scientists developing a booster shot for Covid-19. Photo / Supplied
In an unprecedented collaboration, vaccine experts from Otago and Victoria universities, AgResearch, ESR, Avalia Immunotherapies, South Pacific Sera and Wellington-based Malaghan Institute of Medical Research joined forces for the mission.
The group began eyeing potential candidates that were safe, effective, could be locally manufactured, and aligned with the World Health Organisation’s target product profile for Covid-19 vaccines.
From that process emerged two different shots.
One was what is called a virus-like particle (VLP) vaccine, containing molecules that mimic a virus but, being free of genetic material, aren’t infectious.
“A VLP consists of a protein or proteins that are unique to the virus arranged in layers to form a particle,” Wiig explained.
“Once injected into the body, the immune system recognises the proteins within the VLP as antigens and mounts an immune response.
“Once the body has had an immune response to a VLP, it will recognise the real virus and prevent infection in the future.”
Titled PAN-201, work on that vaccine is now being driven by researchers across the Tasman at the University of Melbourne, who are in talks with South Pacific Sera for pilot-scale manufacture.
VAANZ-201, meanwhile, is a protein sub-unit vaccine – or one that includes only parts of a virus to stimulate the immune system.
“This type of Covid-19 vaccine contains harmless spike proteins,” Wiig said.
“Once your immune system recognises the spike proteins, it creates antibodies and defensive white blood cells. If you later become infected with the Covid-19 virus, the antibodies will fight the virus.”
Both differed from Pfizer’s widely-used Comirnaty vaccine, which used genetically-engineered mRNA to give our cells instructions for how to make the spike protein found on the surface of the virus.
Right now, Wiig said VAANZ-201 was progressing toward GMP manufacture with South Pacific Sera in New Zealand, with a first-in-human clinical trial in New Zealand planned for mid-2023.
“We are currently testing the safety of the vaccine candidate, as well as continuing to demonstrate its effectiveness and how it stacks up compared to other vaccines.”
Having now undergone extensive pre-clinical testing here, the candidate had been shown to have a “unique set of attributes”.
“It elicits a broad antibody and T-cell response to all variants, providing 100 per cent protection against the virus,” she said.
“The immune response generated by the vaccine is also very durable and long-lasting.”
Further, results to date indicated that the candidate could sit stable at refrigerator temperature for several months - and at room temperature for at least one month.
Vaccine Alliance Aotearoa – Ohu Kaupare Huaketo executive director Dr Kjesten Wiig.
With growing clinical evidence that combining different vaccines could bolster our immune response, the researchers were looking at how VAANZ-201 might perform as a booster in people who’d already received an mRNA vaccine.
“Preclinically, VAANZ-201 is looking promising as a new potential Covid-19 vaccine booster vaccine, but late-stage clinical trials are required to confirm efficacy.”
While it’s unclear what future immunisation Covid-19 programmes will look like in New Zealand, Wiig noted the Government had signalled an intention to keep vaccinating vulnerable populations.
“Depending on the outcome of the clinical trials, this vaccine may be a useful home-grown product with a longer-lasting immune response.”
She added the vaccine had also been designed for use in low and middle-income countries that didn’t have the same access during the pandemic.
“By targeting higher-temperature vaccine storage conditions, compared to mRNA vaccines, VAANZ-201 has the potential for use in New Zealand, and also countries where cold-chain requirements are problematic,” she said.
“Our goal is to progress VAANZ-201 to a Phase 1 clinical trial to demonstrate its effectiveness.”
She expected, however, that a major industry, philanthropic or government partner would be needed to move it to later-stage trials and regulatory approval.
“The most remarkable achievement of the VAANZ collaboration was that within a two-year period, the team designed, tested and manufactured a credible vaccine candidate against the pandemic virus,” she said.
“This took place in the context of the global Covid-19 pandemic, where organisations and supply chains, both domestically and internationally, were either closed or disrupted.
