Scientists around the world are racing to develop a vaccine for Covid-19. Chinese company Sinovac gives rare access to how one is created. Video / Sky News / Getty
The Covid-19 vaccine. When is it coming? Will it work? How do we get it to the people who need it most?
William Ray talks to the New Zealand experts who have been tasked with charting our path towards immunity.
Professor Graham Le Gros is an immunology expert. In thedays before Covid-19 his work as research director of the Malaghan Institute focused on convincing the human immune system to attack cancer cells.
That's pocket change compared to massive investments from international pharmaceutical companies and nation states, but Le Gros thinks it's still important for New Zealand to do its part.
"A number of the leading candidates may actually fall over. They may have adverse reactions, or they might be too expensive, or they may not be available in New Zealand," he explains. "As insurance, we are making our own local New Zealand vaccine."
Testing, testing
Even if we don't end up using a home-made vaccine, Le Gros thinks New Zealand may have an important role in testing vaccines developed overseas.
He says our mostly Covid-free environment gives us an unusual advantage in vaccine testing.
"Having the community completely virus-free is a really powerful way to test the ability of your vaccine to stimulate neutralising antibodies in an unprimed, naive population. It's gold."
Put simply, if you give someone a vaccine in New Zealand and that person develops Covid-19 antibodies, you can be confident those antibodies are there because of the vaccine - not because the person had been exposed to the actual virus.
Professor James Ussher from Otago University works alongside Le Gros at the Vaccine Alliance.
He says New Zealand is already in talks to start testing overseas vaccines, but he says the lack of Covid-19 in our community is only an advantage in the early stages of testing.
"In those early stages you're testing whether it's safe and it stimulates a good immune response."
But Ussher says in the later stages, when you are testing the vaccine's real-world effectiveness, you need to test it in an environment where the virus is spreading.
"Clearly we are unable to do any efficacy trials in New Zealand, and hopefully that remains the case."
The next step
Inventing a safe and effective vaccine is only the first step. The next challenge is to build the manufacturing and distribution infrastructure for a global vaccination programme.
Planning is already under way on this front, but Le Gros says it remains a formidable problem.
"We're talking about 9 billion people… Let's take New Zealand, 5 million people. [New Zealand has] never done a vaccine rollout for 5 million people. It's always been just several hundred thousand or just the children who get vaccinated."
And until we know what kind of vaccines work against Covid-19, we won't know what kind of infrastructure is needed to manufacture and distribute them.
Some vaccines need to be grown in cell cultures, others can be produced by chemical reactions.
Some can be stored in an ordinary fridge or freezer, others need to be deep frozen at minus 40C.
Some can be given in one jab, others need multiple doses.
"That's why we're sitting a bit in limbo," Le Gros explains. "Once we get a few more pointers in the next few months we'll say 'aha!' and you'll see a manufacturing strategy put in place."
Even when doses of vaccine start arriving on our shores, that's not the end of the story.
"The vaccine will be an important component of responding to Covid, but it's not going to solve all our problems," says Dr Nikki Turner, director of the Immunisation Advisory Centre at the University of Auckland.
Most experts are predicting Covid-19 vaccines will be released from clinical trials for widespread use in mid to late 2021.
But Turner says it will take much longer for vaccines to be administered to enough people to slow the contagion.
Pedestrians on Queen St as Auckland city returns to Alert Level 2. Photo / Sylvie Whinray
"I don't have a crystal ball, but we are not going to be back to normal by the middle of next year," she says. "We won't have enough vaccine straight off to vaccinate everybody. It'll be a staged process."
Turner says the first doses will go to the most vulnerable, and those at heightened risk of infections like border workers and health staff.
She says most vaccine candidates haven't been rigorously trialled on children and young adults yet, so they will probably be the last to get a jab.
Limited supply means it will take a long time to achieve "herd immunity" - where enough people have been vaccinated that the virus can't spread rapidly.
All going to plan, immunity will gradually rise and infection rates will fall. As that happens, New Zealand will be able to ease border restrictions and reduce social distancing requirements.
"It's a gradual reduction of risk," Turner explains. "We've learned to live with influenza and I think that's what we're going to find with Covid over time. We're going to learn to live with it."
The takeaway message is that even after a vaccine arrives it will still be important to keep up other precautions like border restrictions, social distancing, hand washing and masking.
"We are going to be living with this for a lot longer than many people realise," Turner warns.
