The University of Otago clinical trial at Dunedin Hospital, involving 95 babies, found a course of the new oral vaccine produced a strong immune response in more than 90% of babies.
This has been a major breakthrough because rotavirus, as the most common cause of severe diarrhoea among infants and young children, kills more than half a million children aged under 5 every year, mainly in developing countries.
Ms Lawrence and her son, Logan Beyer, who turns 2 on Friday, attended a function at the university's Hunter Centre yesterday, during which researchers thanked everyone who had contributed to the clinical trial.
Details of the research outcome were also outlined.
The vaccine was initially administered at birth, and had been trialled in collaboration with the University of Melbourne and the Murdoch Children's Research Institute.
Ms Lawrence said it was ''rewarding'' to know that while she had been caring for her son's health, ''we're part of something that's helping people all round the world''.
''It's quite inspiring really to know that I can do something like that.''
Logan's father, Jonny Beyer, said the trial had gone smoothly, and Logan had enjoyed taking part.
An Otago University senior clinical lecturer in women and children's health, Dr Pam Jackson, thanked all participants and helpers and said the trial had been ''a spectacular success''.
Rotavirus infection was ''really rampant around many of the developing countries'', and vaccination was ''a very cost-effective way to deal with a health problem''.
The new vaccine also had significant benefits over other available vaccines, because it could be given to newborns, providing early protection, and was easier and cheaper to administer in poorer countries, Dr Jackson said.
Researchers have also thanked the Health Research Council, which had funded the study.
Otago University graduate Prof Graeme Barnes, now of Melbourne University, has been deeply involved with the new vaccine.
The outcome of this ''pivotal'' clinical trial went well beyond Dunedin and New Zealand and was of world-wide significance, Prof Barnes said.
That wider importance had already been recognised by the World Health Organisation, and the Bill and Melinda Gates Foundation, he said.
Clinical trials had also begun in Indonesia and it was hoped the vaccine would be available for widespread use in 2016.
In New Zealand, rotavirus is responsible for 1500 hospital admissions of children under 5 each year.
