In Australia, we are now seeing a sustained fall in the number of new Covid-19 cases per day.

This is also the case in New South Wales, the state where most of the cases in Australia have occurred. But some of the recently introduced restrictions appear more as a result of panicked political decisions rather than based on biological plausibility or evidence.

Our peak in new cases was around 25 March. Not long after, the numbers started falling and have continued to do so. This is very good news. It is much better than just flattening an epidemic curve. It’s turning around.

However, we are not yet out of the woods. This virus will invariably still be around and spread for months or even years to come. So, we will continue to have small numbers of cases that will persist and reappear as isolated cases and clusters. However, we are now in a better position to control these and stop further spread. We have very efficient public health investigative teams. By any international comparisons we already do a lot of testing – capabilities which are increasing.

The reason we had this fall is most likely due to what was put in place five to 10 days before the peak of the infections. This is because the average incubation period is five days. Therefore, whatever interventions you put in place to try to stop spread today, they cannot be expected at the earliest, to have any observed effects for at least five days.

So our fall in cases would appear to be mainly due to what where did previously – namely locking our international borders, quarantine of returned travellers and anybody who is a close contact of a known case, keeping people with infections isolated until we believe they’re no longer infectious etc.

In addition, we have stopped gatherings of people in most places, particularly indoors where infection is much more likely to spread. We have closed bars, clubs and restaurants. Social distancing has been taken up very vigorously by nearly all of us from what I can see in the streets, supermarkets, parks and in the workplace.

All those interventions when combined appear to have had a major effect and we are seeing the evidence of this in the fall in numbers of new cases.

What we’re not seeing however is evidence for what justifies the latest Victorian and NSW lockdown laws – and so hurriedly put into place.

These were instituted after we were already seeing falls in new case numbers. There is no evidence that I am aware of in Australia, or elsewhere, that if you are outside in the sunshine or open air and keep more than two metres away from other people, that you can acquire or give this virus to anyone else.

Despite this, people who sit on a park bench to have a rest or just watching the scenery are now threatened with fines or arrest in NSW and Victoria.

These overzealous new laws also give out a poor and very mixed message. If it’s deemed reasonably safe to be two metres apart in supermarkets and workplaces, how can this be wrong for people outdoors in our parks, beaches or in the countryside? What we need enforced is not people sitting on benches but these important distancing rules plus stopping groups from gathering – not a complete lockdown.

We need to temper our responses and restrictions based on the evidence we have and what is occurring in our communities. Any new rules must also have reasonable biological plausibility, lower transmission risks and be consistent with our main messaging. The latest responses from Victoria and NSW seem to fulfil none of those criteria.

We have probably been lucky so far in not having much community spread. A probable important factor was because we were in summer here and now autumn, when the virus was being spread worldwide. What we have mainly seen is infection in returned travellers and those from cruise ships. These reflect infections acquired elsewhere, and often in places where there has likely been spread for a couple of months already of unrecognised and wide community spread (eg Europe and the US).

This virus is unfortunately a problem we will have for at least six months and more likely for another 18 months to two years (when hopefully we will have a safe and effective vaccine).

Our upcoming winter will be our next major test. We need everyone to continue to comply with the rules we put in place mid-March and will likely need to do so until at least September.

Some states have now put in overzealous rules and ones that give very mixed messages or have little biological plausibility. Not only will this cause unwarranted and increased social, mental and economic harm, we run the bigger risk that a substantial part of our society in a few months’ time (our winter) might increasingly rebel against many restrictions.

I hope NSW and Victoria can be persuaded to relax on their overzealous restrictions so recently and unnecessarily put in place.