COVID: 2 Pfizer doses and Moderna booster give more protection than 3 Pfizer jabs – Ong Ye Kung

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·Senior Reporter
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Brasov, Romania - February 21, 2021: Pfizer BioNTech and Moderna Covid-19 vaccine on a white background.
Pfizer-BioNTech and Moderna COVID-19 vaccines. (PHOTO: Getty Images)

SINGAPORE — Those who have taken two Pfizer-BioNTech doses and their booster shot by Moderna are more protected against the risk of COVID-19 infection, compared with those who have taken three Pfizer doses.

Across the ages, they are 72 per cent less likely to be infected, compared with 62 per cent for the latter group, said Health Minister Ong Ye Kung on Monday (15 November) during a virtual press conference chaired by the multi-ministry taskforce.

Ong, who is the taskforce co-chair, was citing findings from a recent study by the Ministry of Health (MOH) on the relative effectiveness of Pfizer and Moderna booster shots.

"Both mRNA vaccines work very well as boosters, with Pfizer-Pfizer-Moderna having a slight edge. Regardless, the impact on the reduction of severity of illness is extremely high for both combinations," he noted.

Ong did not elaborate on specifics of the study, including its timeframe, sample size, or demographics.

He, however, added that there are results for other combinations, including those who took all three Moderna doses, but cautioned that the sample sizes for such groups are "not very large and the statistics may not be as meaningful".

In response to a question by the media on the general effectiveness of booster shots in protecting one from the coronavirus disease, the MOH director of medical services Kenneth Mak said that the authorities are in the midst of compiling the data and that it would be released to the public "soon".

"We'll get it to you and we'll make sure that you have information concerning how well the booster vaccine doses are doing," said Associate Professor Mak.

Ong stressed that while data has not been released yet, it is "very clear" that they work.

"The probability of infection and the probability of severe illness has been further drastically reduced," he said. "(For) seniors, the impact has been stark and very significant."

Both Prof Mak and Ong revealed last week that they had taken the Pfizer vaccine for their first two doses, and a Moderna jab for their third.

The taskforce had in September announced that mRNA vaccines under Singapore's booster vaccination strategy "can be treated as equivalent to each other" as advised by the expert committee on COVID-19 vaccination.

Pfizer, Moderna, and Sinovac vaccines are used in Singapore's national vaccination drive. 

Other vaccines under the World Health Organisation’s (WHO) emergency use listing – such as those made by Johnson & Johnson, Oxford-AstraZeneca, and Sinopharm – are approved for use under the special access route for private healthcare providers.

As of Sunday, 94 per cent of Singapore's eligible population – aged 12 and above – have received two doses of COVID-19 vaccines or completed their full regimen. 

Among the total population, 85 per cent have received two doses, 86 per cent have received at least one dose, and 21 per cent have received their booster shots.

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