The latest breakthrough in COVID vaccines isn't using cutting edge technology or a radical new approach to stop the global spread of disease.
Instead, a small team of researchers in the US have gone back to basics, with one key difference: their vaccine is patent-free.
It means any drug maker can use the recipe freely to reproduce the vaccine, without any payment or complex licensing arrangements.
Microbiologist Maria Bottazzi, her colleague Peter Hotez and their team at the Texas Children's Hospital's Center for Vaccine Development last month unveiled Corbevax, "the world's COVID-19 vaccine", and doctors say it could be a game changer.
Corbevax is a protein subunit vaccine, a tried and tested method that stimulates an immune response by directly delivering bits of the virus the vaccine is designed to protect against.
Dr Bottazzi and Dr Hotez's team used yeast to "brew" their own COVID-19 spike proteins, which the coronavirus uses to infiltrate healthy cells to replicate and further assault the human body.
The vaccine teaches the human body to recognise the protein so it's better prepared if the real virus invades.
Novavax uses similar technology, whereas mRNA vaccines like Pfizer and Moderna teach the body to grow COVID-19 spike proteins on its own.
Protein subunit vaccines have been used to fight other viruses like hepatitis B.
Dr Bottazzi and her team have previously used the technology to produce vaccine candidates for SARS and MERS.
"You should never forget that sometimes you have an answer right in front of your nose," Dr Bottazzi told the ABC.
"The fact they may be conventional — some people call them old, some people call them boring — that doesn't mean that they do not work.
"We knew from many years of dealing with coronaviruses that the spike protein is one of the weakest links within the virus."
Managing a small team meant the process took longer than it would in the large pharmaceutical companies.
But clinical trials in India have shown the efficacy of their vaccine against the Alpha and Delta strains is on par with the big brands. Trials are still underway to see how Corbevax holds up against Omicron.
Using yeast to make the protein also meant the vaccine was "a bit vegan", Dr Bottazzi said, and a halal version of the vaccine is being trialled in Indonesia.