On Sept 14, I received an SMS from the Ministry of Health inviting me to make an appointment for my booster shot, exactly six months after my second shot of the Pfizer-BioNTech vaccine.

However, as I was travelling to Germany, I had to wait till I came back this week. I did consider getting my booster shot while in Germany.

There, one has the option to choose which vaccine to take as a booster: Pfizer-BioNTech or Moderna, AstraZeneca or Johnson & Johnson.

I have read reports that seem to point to it being better to mix an mRNA and a non-mRNA vaccine.

In my case that would mean going for AstraZeneca's or Johnson & Johnson's shot as a booster, to complement the two shots of the Pfizer-BioNTech mRNA vaccine I had received earlier.

It is unclear what Singapore's strategy is on this.

Currently it appears that the only option is for Singaporeans to take a third shot of an mRNA vaccine.

It would be valuable for the Government to spell out its views on the relative efficacy of the same versus a complementary booster.

Perhaps the Government could consider fast-tracking the approval of non-mRNA vaccines like AstraZeneca's or Johnson & Johnson's, and give citizens more choice for the first and future boosters.

In the meantime, I have booked a slot for a Moderna booster as studies in the United States indicate it has a slightly higher and longer efficacy than Pfizer.

Rahul Patwardhan