Existing vaccines have found it hard to stop symptoms or transmission, but work well keeping people out of hospital and minimising disease. The pan-coronavirus vaccine may do the same, but it was too early to tell, Petousis-Harris said.
Because of the cost and time needed to tweak existing vaccines to counter emerging variants it means it probably made more sense for companies to look at a new pan-coronavirus solution, she added.
If such vaccines are successful these could be administered annually like the flu vaccine shots over the winter period.
It may avoid a week at home in bed for those who contract the virus, with the uptake of the shots dependent on the perceived effectiveness.
"I think there's a couple of reasons why you may or may not do that. One, you become concerned the infection is causing significant burden of disease and the other is the proof that what you're offering is going to make a difference," she said.
"At the moment, where we're at now, if you've had a booster and then get a second one, that does make a significant difference. So far, we do have strategies that protect the most vulnerable people."
Natural immunity after infection is variable depending on the person, but also on the boosters people had taken.
"Coronaviruses are something that you will get again and again. Hopefully, the repeat performances are very mild and this is something we just need to keep our eyes on."
Petousis-Harris said the US vaccine was looking a year away from being marketed, and that removing impediments had been key to its development being hastened.
"We've now experienced this with Covid, the most rapidly developed vaccines that we've ever seen because we took away the obstacles in getting things through."
Early results of trials are out within the next two weeks, before researchers move to the next phase of pan-coronavirus vaccine development.