Booster shots further reduce infection risk by over 60%

Getting a booster shot with either the Pfizer-BioNTech or Moderna Covid-19 vaccine further reduces the risk of infection by over 60 per cent.

Those who received a Moderna booster shot after two doses of the Pfizer-BioNTech vaccine saw a reduction in infection risk by 72 per cent, while those who took a Pfizer booster shot after two jabs of the Pfizer vaccine saw a 62 per cent reduction.

The statistics was shared by Health Minister Ong Ye Kung yesterday at a virtual press conference held by the multi-ministry task force on Covid-19.

He said the Ministry of Health (MOH) recently did a study on the relative effectiveness of Pfizer and Moderna vaccines as booster shots in terms of reducing infection risk, and compared two combinations.

One combination is three consecutive shots of the Pfizer vaccine (two regular jabs and one booster), while the other combination is a Moderna booster shot and two regular doses of the Pfizer jab.

"Regardless, the impact on the reduction of severity of illness is extremely high for both combinations," Mr Ong said.

He noted that for other combinations, such as a Pfizer shot after two doses of Moderna vaccine, sample sizes are not large, and the results may not yield meaningful statistics.

Mr Ong and Singapore's director of medical services Kenneth Mak both took a Moderna booster shot after two jabs of the Pfizer vaccine.

Mr Ong also explained why Singapore's reported vaccine coverage of 85 per cent appears to be lower than the reported figures in some other countries. "This is because some countries report vaccine coverage against the eligible population, whereas we report vaccine coverage against the total population," he said.

This means that of the remaining 15 per cent who are not vaccinated, 1 per cent are not living in Singapore, 9 per cent are children below 12 and not eligible, and the remaining 5 per cent are eligible but chose not to be vaccinated, he added.

Mr Ong said: "So if we recalculate this based on eligible population, we are around 94 per cent vaccinated. It is one of the highest coverages in the world.

"MOH will provide both figures henceforth in our daily press release to give a fuller picture of the progress of our vaccination exercise."