SINGAPORE — A study by the National Centre for Infectious Diseases (NCID) has found that a higher proportion of non-vaccinated Covid-19 patients above the age of 50 needed supplemental oxygen, compared to those who are either fully or partially vaccinated. 

The study, which analysed the effect of age and vaccination on Covid-19 patients, examined 1,165 non-vaccinated Covid-19 patients who were admitted to NCID between February and December last year, and 328 infected patients who were admitted to NCID between April 28 and June 27 this year. 

Those in the earlier group were not vaccinated because the vaccines were only available in December last year. 

In a statement on Thursday (July 22), NCID said that of the 153  patients aged above 50 who were admitted to NCID between ​April 28 and June 27 this year, 41.8 per cent of those who were not vaccinated required oxygen support, compared to 11.1 per cent for those who were partially vaccinated and 1.7 per cent for those who are fully vaccinated. 

Only one fully vaccinated Covid-19 patient required supplemental oxygen and this was a 98-year-old patient.

“The findings show the beneficial effects of (the) vaccine,” NCID said. “In addition, there may be partial protection with one dose of vaccine before completion of the two-dose regimen. 

“However, it should be stressed that one should complete (the) full vaccination (regime) of two doses for maximum protective effectiveness.”

The study also found that none of the fully vaccinated patients above the age of 50 required high dependency or intensive care, while 10.6 per cent of those in the same group who were not vaccinated or partially vaccinated required such care. 

“Generally, fully vaccinated patients had milder illness and all survived,” NCID said. 

Among the 328 patients this year, 192 were not vaccinated, 38 were partially vaccinated and 98 were fully vaccinated.

The findings also showed that the Delta virus strain is associated with the increased need for supplemental oxygen, compared to the original virus from last year.

Of the 328 patients admitted this year, there were 247 patients for whom data on variants was available. 

Of these 247, the vast majority — 99.6 per cent of them — were infected with the Delta variant.

When it came to Covid-19 patients above 50 years old who were not vaccinated or partially vaccinated, the study found that 33 per cent of the patients from this group needed oxygen support compared to 13.6 per cent of patients who were infected with the original coronavirus in 2020. 

“The Delta variant is highly transmissible and associated with more severe disease among unvaccinated and partially vaccinated patients,” NCID said. 

“Hence, NCID urges everyone, especially the seniors, to be vaccinated as soon as possible.”