Our government’s reluctance to set a vaccine target doesn’t sit well with me. The current mantra is to set targets for everything, so that you can see if you have achieved them or not and to encourage people to reach them. Whether one should have a target for everything is questionable, but whether one should identify targets for really important things like vaccination seems obvious.
There are a range of factors to consider when setting targets, targets need to be:
- Achievable – there is no point in having a target that everyone thinks is stupid from the outset.
- Measurable – no point having a target if you can’t know if you have reached it.
- Communicated – no point in having a target no one knows about, or where they don’t know progress towards the target.
- Timebound – there is generally no point in having a target with infinite time in which to achieve it, this removes incentives to act.
It is also important that targets don’t have perverse incentives – like when you incentivise planting a billion trees with a large government subsidy, and then find that farmland is turning into permanent forest, although you need food more than trees, or that lots of flammable trees are being planted in a time when wildfires are more likely because of climate change.
I get the impression that our government is currently so unsure of what vaccination target they want to reach, that they don’t want to set one. Is it that they don’t want to aim too low, tell people ‘we made it’ and then find out that level of vaccination is not enough to slow the tide of COVID-19? Or is it that they are scared of aiming too high and failing? Other governments are starting to make statements about sufficient levels of vaccination. A number currently being commonly bandied around is 72% of the total population which roughly equates to 90% of adults (people aged 16 and over), although that differs by country as different countries have different proportions of children in their populations.
So, I thought I would take a look at vaccine leaderboards and see what the new COVIDF1-9 case rates are for countries as one goes down the vaccinations ranks (looking at ourworldindata daily new case graphs). If there is a critical level of vaccination, one would think it might show up in terms of control of COVID-19.
Here is what I found – if one ranks countries according to their level of full vaccination, one has to get to number 9 to find a country where the numbers of new cases are increasing (Belgium), and number 11 (Canada) to find a place where they are increasing steeply. Number 8 (Denmark) has 71% of the country fully vaccinated. I wonder if this is a coincidence, or if the people advising governments on vaccination targets are going through a very similar (but probably more sophisticated) process.
|Country||Population||Partially vaccinated||Fully vaccinated||Trend in new cases|
|United States||365,767,674||61%||52%||Up steeply|
There are all sorts of reasons my basic analysis could be flawed. For example, I don’t know:
- How uniform vaccination is in each country – uniformity will reduce spread.
- What degree of restrictions each country has – restrictions will also reduce spread.
- Numbers of people who have immunity conferred as a result of getting COVID-19.
- When the vaccinations were administered – there is growing evidence that vaccine efficacy wanes substantially by around 6 months after administration.
However, if the New Zealand government would like my advice, I would be choosing a 75% of total population vaccination rate as a goal. We have approximately 20% of our population under 12, who can’t yet be vaccinated. So let’s set an optimistic, but not unachievable target of vaccinating 94% of those who can be vaccinated by the end 2021. Please Jacinda? Clarity and kindness are closely aligned.