Vaccinated individuals accounted for three-quarters of Singapore's COVID-19 infections in the last four weeks, but they were not falling seriously ill,
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.
The Singapore data also showed that infections in the last 14 days among vaccinated people older than 61 stood at about 88%, higher than the figure of just over 70% for the younger group.
Linfa Wang, a professor at Duke-NUS Medical School, said elderly people had been shown to have weaker immune responses upon vaccination.