I was wondering because if the virus isn't natural, trying to predict/model how it will behave becomes harder undermining any efforts to do so as you maybe can't use previous pandemics as a reference.
THe question of a lab leak is not exactly the same question as whether the virus is 'natural' or modified in some way. For example, entirely natural viruses could be studied in labs that then have an accident.
In terms of modifications to viruses, various different sorts are possible, and different properties could be modified. Some of those would affect specific properties of the virus, but would not really be expected to eliminate the overall 'rules' for how coronaviruses behave. And even if they did, the dynamics of pandemic diseases in humans are inevitably tied to general concepts such as population immunity, and the evolution of the virus. I will continue this point when answering your other question:
Did you say a witness said something like this time natural or synthetic immunity wasn't working as hoped, but covid has 'faded' away to a point.
Sorry, I realize your not a witness but these are questions I can't ask them directly!
No, I did not say that. The pandemic is basically progressing as expected so far, and the only hopes that have not been realised are ones that were overly optimistic or based on false premises in the first place. Personally I have moaned about the premature presentation of such hopes at times in recent years, but this isnt something witnesses to the inquiry have mentioned so far.
The simplified version of what is expected is as follows:
The new disease has a field day to start with because the population has no immunity against it.
Over time population immunity starts to increase as a result of people getting infected and parts of their immune system learning to recognise the virus.
If vaccines are invented and deployed, that further adds to this phenomenon.
The virus becomes endemic and continues to circulate in humans, but it causes less hospitalisations and deaths than it did at the start because huge numbers of people are better able to fight the virus.
The overly optimistic version would go further than the above, by introducing the idea that the population gains the sort of immune response that can also knock transmission on the head. Under that scenario you could stand a chance of stopping the disease from remaining endemic. You could hope to ultimately eradicate it, although concerted action and a very prolonged effort would likely still be required to do so.
We would need to generate more transmission-stopping immune responses in order to get closer to that second scenario, eg by inventing and deploying vaccines that do a much better job of stopping transmission. Even under those conditions people would probably not dare to predict that the disease would be completely eradicated, but it would make a difference to size of future waves, ongoing healthcare pressures, ongoing death rate etc.
In addition to how the human immune picture evolves, the evolution of the virus can also make a difference to that picture. Predictions about what will happen with that dont stand a good chance of being correct, regardless of whether the vaccine was entirely natural or modified to start with.
A few examples of what happened to some previous pandemic viruses later on:
The descendants of the 1968 influenza virus are still with us, still cause epidemics some years, still kill plenty of people, often older people whose immune systems are less capable of fighting off the virus. Vaccines have reduced the deaths but are not perfect and deaths still occur, as they did here last winter.
If the 1890 pandemic was caused by the OC43 strain of a coronavirus, what was long ago capable of causing a nasty pandemic in the years when it first arrived, now tends to cause nothing more than a cold.
This is my own attempt to explain the basics. Only certain parts of this sort of picture have come up in evidence so far.
