No second wave as long as there is adequate functional testing and tracing capability. Literally noone in their right mind wants to go through the last few months again. The science journals have basically shown (at least not the recently discredited ones!), the vast majority of transmission (when R0 was 2) is symptomatic transmission (0.9) and presymptomatic transmission (0.8). The way you prevent presymptomatic transmission is by testing and tracing militantly. As long as the true positive rate is <1% you don't tend to overwhelm testing capacity. The way you prevent symptomatic transmission is hard work- you have to figure out the individual vectors within your society, figure out the behaviours that are causing it to spread and then find a way to stop those behaviours....ie abattoirs in the west, truck routes in Africa, dormitories in Singapore... Given that the rest of the world is also taking this pretty seriously, and that quite a lot of developed countries at least are tracking down with infections, it actually becomes exponentially easier to control the virus. Whether true eradication is possible is still unclear. It appears that SA, Tasmania, WA, NT and ACT have at least completely stopped community transmission, and that QLD is on thee verge as well.
More importantly- numerous studies have now shown fairly robust neutralising antibody responses, suggesting that a vaccine is probable, although the timing is uncertain. I suspect one way or another, the outcome will be very significant suppression/eradication. Given that herd immunity does not exist- some degree of caution and hygiene is going to be necessary until enough time passes that we can be sure of eradication or that a vaccine has been developed. Most countries with substantial testing and tracing capabilities seem to have the virus well under control, but no handshakes, handwashing etc are the new normal.***
***outbreaks are likely to occur. The key is to stop lots of chains of transmission spreading outwards. As long as you find a chain and interrupt it quickly, it is actually not a huge problem (eg - school infected, forced 48 hour quarantine whilst close contacts are checked + deep clean, school reopens, meanwhile rest of society largely functional).
