John Rumm wrote
bert wrote

Totally illogical. If you have been vaccinated what have you to fear?

Several things;

Vaccination will not necessarily prevent you being infected, all it can do
it improve the bodies response, making it faster and more effective. The
aim being to prevent serious illness, hospitalisation, long term
complications and/or death.

In fact thats true of many current vaccines for other viruses.

Not all tho.

The immune response can only do its thing, once it has already been
"invaded" by the pathogen. So is still likely that a small window of time
could remain where you could transmit the infection on. Hence vaccinated
people tooling about like they are now captain Teflon are a liability for
everyone else.

Mutations are a continued and natural part of the lifecycle of a virus.
Since mutations are random, a few will improve the virus' ability to
survive and reproduce, but many will lower it. Normally when there is
already a dominant and successful strain in broad circulation, even
potentially successful mutations may still not actually succeed since too
many of the hosts they reach already have a sufficiently similar infection
from a another strain[1], that they can't compete.

This does however make the start of a vaccination program a particularly
risky one since it will drive down the reproductive rate of the current
dominant strains, giving more scope for variants to gain traction.

Thats not accurate given that there is no reason why the non current
dominant strains should be less susceptible to the vaccine.

If these also happen to be less well targeted by the vaccine,

No reason why they should be.

then you can quickly find yourself back at square one. The way to minimise
the rate of production of viable mutations, is to reduce the number of
infected hosts.

That means that all the non vaccine protective measures need to stay in
place for longer than may at first glance appear necessary in order to
keep driving the overall number of infections down as low as possible.

[1] It has been demonstrated that it's possible to contract two different
COVID 19 variants at the same time, although this is thought be very rare.

Very rare indeed in fact given only a handful in hundreds
of millions infected now, likely more than a billion.