SINGAPORE, July 23 (Reuters) - Vaccinated individuals accounted for three-quarters of Singapore's COVID-19 infections in the last four weeks, but they were not falling seriously ill, government data showed, as a rapid ramp-up in inoculations leaves fewer people unvaccinated.
While the data shows that vaccines are highly effective in preventing severe cases, it also underscores the risk that even those inoculated could be contagious, so that inoculation alone may not suffice to halt transmission.
Of Singapore's 1,096 locally transmitted infections in the last 28 days, 484, or about 44%, were in fully vaccinated people, while 30% were partially vaccinated and just over 25% were unvaccinated, Thursday's data showed.
While seven cases of serious illness required oxygen, and another was in critical condition in intensive care, none of the eight had been fully vaccinated, the health ministry said.
"There is continuing evidence that vaccination helps to prevent serious disease when one gets infected," the ministry said, adding that all the fully vaccinated and infected people had shown no symptoms, or only mild ones.
Infections in vaccinated people do not mean vaccines are ineffective, experts said.
"As more and more people are vaccinated in Singapore, we will see more infections happening among vaccinated people," Teo Yik Ying, dean of the Saw Swee Hock School of Public Health at the National University of Singapore (NUS).
"It is important to always compare it against the proportion of people who remain unvaccinated...Suppose Singapore achieves a rate of 100% fully vaccinated...then all infections will stem from the vaccinated people and none from the unvaccinated."
Singapore has already inoculated nearly 75% of its 5.7 millio