Experts say the best COVID-19 vaccines may not actually exist yet, with researchers set to learn from the first rollouts and evolve the science to target new mutant strains and specific populations such as older people.
Key points:
- Vaccine makers have started focusing on the mutant strains that have appeared in Brazil, the UK and South Africa
- A number of Australian developers have made this move, saying it will give them a point of difference against the frontrunners
- According to the World Health Organization, there are about 200 COVID-19 vaccine candidates still in development
It comes as two Australian-based vaccine developers reveal they are re-focusing their vaccine candidates to target potential new mutant strains of the virus such as those seen in the UK, South Africa and Brazil.
Experts say the current vaccines should still work against the current variant with mRNA vaccines such as Pfizer’s — which will be the first vaccine to roll out in Australia next month — particularly suited to quick re-engineering.
However, there are no guarantees, with tests only conducted in a laboratory environment so far.
This week the team at Oxford-AstraZeneca, which is a critical part of Australia’s vaccine rollout, confirmed it is designing new versions of its jab in response to the different variants.
According to local vaccine developer and Flinders University director of endocrinology Nikolai Petrovsky, the data to back up the existing vaccines’ effectiveness against the mutant strains is still “light”.
Professor Petrovsky is behind the Australian company Vaxine and its COVID-19 vaccine candidate “COVAX-19” which completed its phase 1 trials in August showing it was “safe and effective”.
However, as the Australian Government backed in the University of Queensland’s vaccine, later abandoned because of false-positive HIV results in phase 1 trials, Professor Petrovski said the company was left with no government funding and was forced to look at alternatives.
He said the vast majority of current vaccines in development had not properly investigated the evolution of COVID’s mutant strains.
“Given we are slightly behind the frontrunners, we had to look strategically at if there was something we could be doing that the frontrunners haven’t done,” Professor Petrovski said.
“Obviously that will set us back a little. But obviously it will put the other companies back further if they have to start again.
“Our vaccine platform is designed to be rapidly pivoted, as it was designed for influenza, which pivots on a regular basis, so we’re hopeful this is viable.”
Professor Petrovsky said the virus and vaccine development “changes daily” and his team of 20 were constantly juggling its focus on the ever-changing science and the need to lobby governments for funding to continue COVAX-19’s development.
“That’s been one of the difficult things to manage,” he said.
According to the World Health Organization, there are about 200 COVID-19 vaccine candidates still in development.
Of these, at least 52 are in human trials.
The Australian Government has so far committed to three — Pfizer, Oxford-AstraZeneca and Novavax — and signed up to the global COVAX initiative, which will potentially give it access to about seven other vaccines in development if required.
The Pfizer vaccine is set to be rolled out in Australia next month, with AstraZeneca following.
The vaccine from Novavax is expected by “mid 2021”, with a spokesman telling the ABC the company will have its interim data from its phase 3 trial done within the next two months.
The Australian Government also confirmed it is in discussions with “a dozen” other vaccine manufacturers, including pharmaceutical giant Johnson & Johnson, which vaccine experts have identified as an impressive candidate.
Professor Tony Cunningham, a vaccine expert of 40 years, said the development of COVID-19 vaccines would be a “continuing evolution” and we’ll see many vaccines in the future “that may not exist yet”.
“That’s the usual progression,” he said. “That’s what happened with the shingles vaccine, and with influenza.
“We’ve all been blown away with the results on the mRNA vaccines.
“But there’s no data yet being published. We don’t understand how much these vaccines will work with stopping the spread of the virus and with older people, and new vaccines will come along.”
The issue of spread and the vaccines’ impact on older people was raised by the Federal Government after the National Cabinet meeting on Friday.
In a joint press conference, Prime Minister Scott Morrison and Deputy Chief Medical Officer Michael Kidd said they were “still learning” about the effectiveness of the vaccines in preventing transmission and spoke about the rollout in aged care homes, confirming it would not be compulsory.
Professor Cunningham, who helped develop the shingles vaccine with global pharmaceutical giant GlaxoSmithKline, is in the very early stages of developing a COVID-19 vaccine with Sydney’s Westmead Institute using similar technology with a focus on protecting older people.
Another local vaccine developer, Monash University’s Colin Pouton, said it was “inevitable” that vaccine companies would look at the mutant strains and focus on particular demographics.
Professor Pouton is in the early stages of developing an Australian-first mRNA vaccine focused on what he called the “tip of the spike” rather than the “whole spike protein” which, he said, was the focus of all vaccines being rolled out currently.
Like Professor Petrovsky, he said their team was looking for a “point of difference” in the vaccine race and is working in conjunction with Melbourne’s Doherty Institute to look at their “tip of the spike” technology.
“The problem is if you vaccinate with the whole spike it will just raise more “non-neutralising” antibodies and, particularly with older people, you get the same result,” Professor Pouton said.
“We think there’s an advantage focusing on that [tip], the very end that binds to the receptor, which will direct the immune system to create more neutralising antibodies.
“We’re hoping this will distinguish us from the other quite successful vaccines.”
On the mutant strains, Professor Pouton said mRNA technology was “particularly suited” to targeting the new strains of the virus and it something they were focused on.
“With mRNA you can administer a cocktail quite easily, it is designed to hit various strains,” he said.
“The mutations will be an ongoing thing [but] the mRNA, and protein sub-unit technology can quite easily produce a vaccine against a mutant strain.”
He said the team was working towards a clinical trial mid year.
Doherty Institute director of epidemiology Jodie McVernon said there were “knowns” and “unknowns” with the vaccines and it was inevitable that the virus would “evolve, change and mutate”.
“We have to continue to monitor this as a global community,” Professor McVernon said.
“We need to understand [the mutations], characterise them and figure out whether or not they will require any changes to our vaccines or strategy.
“But a year ago I would have told you it is not possible to be where we are right now.
“We are in a good position.”