Protection from Covid-19 vaccines wanes faster among elderly: NUS study

Senior citizens should consider receiving booster doses of the updated Covid-19 vaccine regularly, according to a recently published study by local researchers.

- Judith Tan

This is because in people over 65, protection from the first two doses wanes faster as they have a lower immune cell count.

The study was led by Dr Vanda Ho, a PhD student at NUS Yong Loo Lin School of Medicine.

It involved 29 participants, 14 of whom were aged between 66 and 82, and the rest being younger adults between 25 and 39 years old. They all received two doses of Pfizer's mRNA Covid-19 vaccine.

The findings of the study were published in the peer-reviewed journal Ageing Cell in February.

"Older adults had a significant increase in neutralisation after the second dose, but this was still lower than the younger adults, despite the former being robust," said Dr Ho.

So, it is important for older adults to go for booster vaccinations regularly to protect themselves, she noted.

The immune system can be triggered by a vaccine to produce neutralising antibodies in response to the virus or bacteria in the vaccine, resulting in the system recognising and fighting the infection naturally when exposed to the disease later.

As a geriatrician at the National University Hospital, Dr Ho often sees older adults come into the wards with infections for the first time.