[Lewis Thomson (OP)]

With the lifting of covid restrictions, Terry has been wanting to know the answer to this.

"Can you tell me the difference between "living with covid 19" and herd immunity?"

Leave your answers in the comments below...

[alancalverd]

Herd immunity occurs either when a herd has evolved inherent immunity (a very slow and wasteful process) or all the most vulnerable members of a generation have died and the youngest have had sufficient exposure to have developed their own immunity, or a vaccination program has ensured that so many members are immune that the remainder are unlikely to come in contact with the disease. 

[Bored chemist]

On the other hand, "living with covid 19" means very little.
It's a  buzz word designed to distract people from a failed Prime Minister.
When the going gets tough... BoJo hides in a cupboard.

The practical outcome will be "dying with covid 19".

[evan_au]

Herd immunity means that enough people are vaccinated/recovered from previous infection that the Effective Reproduction Number is less than 1 (R_eff < 1). Infected tourists might expose a few people and cause localised outbreaks, but the outbreak will die down with no additional steps (eg lockdowns or contact tracing).

"Living with COVID" can be achieved by:
- Herd Immunity, as described above.
- and/or ongoing restrictions like mask wearing in vulnerable places like hospitals and aged care homes, to keep the death rate to "tolerable" levels (whatever that means)
- and/or assuming that everyone who is vulnerable (due to age, comorbidities, etc) has had a chance to be fully vaccinated, and everyone else has decided to take their chances with the virus
- In the extreme, it can mean encouraging everyone to go to work even if they are sick, because "it's just like the common cold" - which for many it is. In the absence of a vaccine or masks, this attitude led to gross hospital overload in Milan in the early days of the pandemic.

All of this ignores the fact that in a mostly-unvaccinated third world (and in immune-suppressed patients), new variants will pop up with some regularity, and some of these will evade the current vaccines and current herd immunity (as Omicron did; fortunately, it was less lethal if you did catch it).
- If a new variant arises which is as contagious + vaccine resistant as Omicron, and as deadly as Delta, then deaths will rise dramatically, hospitals will become overloaded, and lockdowns, mask wearing and other public health measures will be required again.

"Living with COVID" means that politicians are walking a tightrope between killing too many people with COVID (thus annoying the surviving voters), and shutting down businesses and entertainment (thus annoying the surviving voters and political sponsors).

Ironically, in Australia, we survived the waves up to and including Delta (including many lockdowns) with surprisingly little economic impact.
However, because Omicron looked milder, the state governments (except WA) decided to "Let it Rip": the daily death rate of Omicron was 5x the death rate at the peak of Delta. This caused so many people to be ill simultaneously that it shut down transport and many businesses. This led to fresh food shortages (no-one to pick or ship food), and had a larger economic impact than the lockdowns of previous waves.

The long-term impacts of "printing money to help people who lost their jobs" are yet to be felt; in previous generations, economists would have predicted that this action would lead to long-term inflation over the next decade. But with inerst rates at about 0% in many countries, it's unclear what will happen now...

[set fair]

Basically there is no such thing as herd immunity with covid, at least for now. Omicron started in the UK with 90% seropositivity and this has now reached 98% and the prevelace of infections is 80% higher now than the height of the Alpha wave, according to the Zoe symptom tracker - which estimates 145,000 new symptomatic cases per day. So who are these people being infected by?

Perhaps we could achieve herd immunity by vaccinating every 3 or 4 months. That's not going to happen - 56% have had the booster, although contrary to what we're told it's quite sustainable and it would be the cheap option.