The former Massey University scientist figured it would take several years to produce one.
"Perhaps if this disease becomes well established, then in five years' time [it] may be able to be vaccinated [for Covid-19] like they are with flu at present … but there's just no way a vaccine can be developed, validated and put into production while we're still in the epidemic phase.
"What's critical for people right now are things like hand-washing and not touching when greeting people – all of these things can be highly effective."
Associate Professor Helen Petousis-Harris, a vaccinologist at the University of Auckland, agreed that hygiene and quarantine were the most effective measures in the short-term.
"Right now, we've got this wave and we don't know whether it's going to become a disease that circulates around, a seasonal one like the flu, or one that just disappears," she said.
"But what we are starting to see already is the mortality rate coming down where it's being managed well."
For New Zealand, responding to the epidemic in a controlled and protracted way was a better scenario than a "fast-burn" outbreak that could overwhelm the health system.
In the long run, she said, it would be a vaccine that stopped it.
She put much of the swift response by global vaccinologists down to the recently-founded Coalition for Epidemic Preparedness, which had a goal of getting a vaccine into human testing within just 16 weeks of a new pathogen's gene sequence – something completed for Covid-19 back in January.
Approaches to developing a Covid-19 vaccine ranged from the sort of technology used in familiar vaccines like hepatitis and HPV, to the more cutting-edge using DNA platforms and innovations called viral vector templates.
Petousis-Harris saw solving the Covid-19 vaccine challenge is a massive test – and one that could change the landscape for the better.
"I think we are entering an exciting new era of vaccinology where the previously impossible becomes possible."
Those advancements would be needed: Morris said animal-to-people transfers which have driven nearly all the recent major global disease outbreaks were growing because of a rising population and increased interaction with wildlife.
Climate change, too, threatened to widen the geographical spread of important diseases.
"Events such as the current epidemic are going to become more common in the future, unless we adopt a more proactive approach to their prevention and detection," he said.
"New Zealand has acted very sensibly to protect the population in the current epidemic."