A Response to an "Anti-Vaxxer".

"... the big question is whether the current vaccine is still appropriate given the new variants."

The prevailing variant in Singapore now is Delta. It is more transmissible. And has been shown to infect Children more. So, your belief that "Kids immune are tip-top, unlike our half-dead seniors" is a fallacy.
Also, MIS-C.
And "Long Covid."

"what's the rush?" No rush. take your time. If you do not need to work for a living, if you child do not need to go to school, if you are prepared or prefer to isolate at home, and avoid social situations, if you would like to be a "hikikomori" (and wish your family to be hikikomori too), your best bet to avoid the Delta or Omicron (if and when it becomes prevalent) variant is to withdraw from society? Or did you have another viable plan?

The anti-vaxxers/vaccine-hesistant primary strategy is to "wait and see", while they accumulate "facts" to support their flawed, fallacious beliefs. Like: we don't need to deal with Delta now, there is going to be a NEW variant and how do we know the vaccine will work against the new variant?

How do we know it won't? That's just the anti-vaxxer rationalising their position.

[Experts are concerned. But they do not know how the new variant might behave compared to Delta. That still remains to be seen, But Anti-Vaxxers are finding every little fact or speculation to support their position.]

The logical fallacies of the anti-vaxxer are:
1) Being unable to respond to the CURRENT situation and reality. Instead of facing the Reality that Delta is HERE NOW, they worry about a) When Omicron is here, later, maybe. or b) possible, unspecified side effects of the vaccine 3, 5, 10 years from now. If your child gets Delta now, Omicron may be moot. Or it may be another problem weeks or months down the road. If your child gets Covid and gets MIS-C or Long Covid subsequently, unspecified and speculative and possibly *IMAGINARY* side effects 3, 5, 10 years down the road are not worth discussing.

2) Omission Bias. Parents are most prone to this bias when it comes to vaccination. The choice a parent face is a) vaccinate the child and the child gets an adverse side effect (from the vaccine). Or b) don't vaccinate the child and the child gets the disease the vaccine would have protected the child against. Which is more morally wrong? Well, most parents will choose b) as the more MORAL choice, or the Choice that they are more able to live with. In other words, we have a BIAS to DO NOTHING, and if something bad happens (from doing nothing) that is just BAD LUCK. But if you CHOOSE to do SOMETHING, and that happens to have a bad outcome, then you would feel that it is YOUR FAULT. This is a Logical Fallacy. Or a Logical Bias. But hey, parents need to feel good right?

"Why fix the unbroken?"

Sure. There is nothing broken right now.

Video on "The Science of Anti-Vaccination", with an explanation of the Omission Bias.