What do you do when the most powerful weapon you have against rising levels of Covid-19 fails to deliver?
Lockdown this time around is a letdown.
It may still be a last resort but with slightly more than a week to go, having drained so many spirits, it has fallen short of expectations.
Public health officials are left feeling somewhat stranded before they convene next week to come up with a plan to save Christmas.
After all the economic and social pain we are stuck on around 400 cases a day, with 330 cases reported yesterday. There will need to be dramatic improvement next week but it is unlikely to be driven down to the target of 50 to 100 cases a day.
Other countries in Europe are finding it tough going also compared to the last lockdown in the spring.
Germany, in partial lockdown since November 2, has said restrictions are causing case numbers to stabilise “somewhat, but too slowly”.
It’s not that our own lockdown has not taken us out of the danger zone we were in. The 14-day incidence in late October was at 300 per 100,000 and it is now down to 113.1 per 100,000 yesterday.
Daily cases were well over 1,000 and they have been more than halved. But as chief medical officer Dr Tony Holohan said we have “lost a week” when cases should have been driven down further.
So if lockdowns have lost some of their firepower, the question is what is behind it?
Some scientists are increasingly of the view across Europe that it’s not just a case of behaviour, where people are taking shortcuts with Covid-19 rules, but also one of biology.
It may be more difficult to control in winter, not just because more of us are huddling indoors.
Viruses survive outside the body better when it is cold. And there is also less UV light from the sun which could inactivate the virus.
Some eminent specialists from bodies like Harvard Medical School believe the virus survives best in low temperatures in dry air.
They have signed a petition to WHO to establish global guidelines on indoor humidity.
The advice is that opening a window or using a humidifier or air purifier could help prevent dry air.
It is relevant to not just homes but also offices, hospitals and nursing homes.
The other influences which need to be remembered on the slowing of progress in this lockdown include the fact schools and creches are open this time, unlike the last lockdown.
Construction sites are also open. There were all shuttered during the spring lockdown.
Questions also remain over how efficient the HSE’s test and trace system is and the time has come for this to be independently evaluated to find if there are weaknesses which are delaying the detection of cases and fuelling the spread of the virus.
It has still to start a process of lookback to track the source of transmission over a number of weeks.
In any ordinary time, lockdown would allow us to reduce infection and then buy time after it is lifted.
The big complication this time is the unknown impact Christmas socialising will have in the crucial weeks post lockdown.