A study by the SMU Centre for Research on Successful Ageing (ROSA) found that amongst elderly Singaporeans who opt not to be vaccinated against COVID-19, about 80 per cent cited side effects as their main concern, whilst 25 per cent did not believe in any form of vaccination. The survey, conducted in June, also found that socioeconomic status, education level, and type of housing, are also important determinants as to whether or not these seniors are vaccinated as early as possible. The report suggested that the government targets its campaigns on seniors aged 71 to 75, who are of lower socioeconomic standing, and live in smaller housing units.