MASS immunisation against Covid is underway in Indonesia. But unlike the UK, the south-east Asian republic is prioritising working age adults of 18 to 59 with the goal of achieving herd immunity faster and rebooting the economy.

Dale Fisher, a professor of infectious diseases at the National University of Singapore, told Reuters this week that he understands the rationale.

“Younger working adults are generally more active, more social and travel more so this strategy should decrease community transmission faster than vaccinating older individuals,” he said.

Indonesia’s health ministry says it needs to vaccinate around 181 million citizens - roughly 67 per cent of its population - to achieve herd immunity.

Some scientists remain sceptical, however, particularly because it remains unclear to what extent the vaccines prevent transmission of the virus as well as disease.

HeraldScotland: UK Covid rates are running well above those in IndonesiaUK Covid rates are running well above those in Indonesia

There is no guarantee that the approach will reduce mortality among older Indonesians, but the country - which has had 23,500 confirmed Covid deaths compared to the UK’s 78,500 - is using China’s Sinovac vaccine, whose developers say there is not yet enough data from clinical trials about its efficacy on elderly people.

It is a strategy that will be closely watched by other nations - particularly those, like New Zealand or Australia, whose cautious handling of the pandemic has kept cases and deaths low, buying them time to weigh up which vaccine they want to use and how they want to deploy it.

READ MORE: Anger as 'back office' NHS staff invited for Covid jags 

The UK does not have the luxury of time in what has been dubbed a ‘race between the virus and the vaccine’.

With cases growing exponentially (the UK is currently recording 826 cases per million compared to 27 per million in Indonesia, although its testing rates are comparatively low for the Asia-Pacific region), the imperative here is to protect the NHS, which means prioritising the vaccine to those most likely to require hospitalisation.

Between March 1 and December 18, people aged 75 and older accounted for 5,769 (42 per cent) of Scotland’s Covid hospital admissions, compared to a total of 4,962 among people aged 15 to 64.

The median age for patients in intensive care, in both waves one and two, is 61, and three quarters of Covid deaths (according to National Records of Scotland) have occurred in people aged 75 and older.

HeraldScotland: Priority list for vaccinations, as recommended by the UK Joint Committee on Vaccination and ImmunisationPriority list for vaccinations, as recommended by the UK Joint Committee on Vaccination and Immunisation

Nonetheless, the Indonesian experiment underlines the fact that the is no single or perfect way to rollout the Covid vaccinations.

One of the anomalies of prioritising those in their 80s and 90s first, for example, is that it disproportionately benefits more affluent communities where people live longer.

Dr David Chung, the former vice president of the Royal College of Emergency Medicine in Scotland, rightly summed up the dilemma when he tweeted: “We know poor people die younger (in my catchment half have died by 75). By prioritising the vaccine by age, you are giving it to the richest first, and compounding health inequalities”

HeraldScotland: (Source: Public Health Scotland)(Source: Public Health Scotland)

This is a gap that has been widening notably in the second wave.

According to the Scottish Intensive Care Society Audit Group (SICSAG), there have been twice as many Covid ICU admissions since August for people from the poorest areas of Scotland compared to the wealthiest (30% compared to 14%).

In the first wave the difference was much narrower: 24% to 17%.

READ MORE: If only taking back control had also applied to our borders in a pandemic

We know that the poorest have been twice as likely to die and the less well-off are much more likely to work in essential occupations which cannot be done from home.

While the focus has been on immunising frontline NHS staff (albeit with questions raised about delays to vaccinations for primary care teams and jags for "back office" admin staff) analysis by NRS has shown that Covid death rates are actually higher among factory workers, retail staff, drivers, and people in the construction trade.

HeraldScotland: (Source: Public Health Scotland)(Source: Public Health Scotland)

The counter to this of course, is that vaccination is not the only solution: we could arguably do just as must to protect these individuals in low-paid and insecure work if we significantly improved the financial support and facilities for self-isolation, given that many will not qualify for sick pay and live in overcrowded accommodation.

Dr Zubaida Haque, a member of independent SAGE, told Newsnight this week: “The reason why over-80s are being prioritised for the vaccinations is because age is a significant predictor of risk in Covid-19.

“But if the Government focused on improving test, trace, isolate and support - and it’s the isolate and support that matters the most - then that is also going to get us out of this pandemic, because that is going to suppress the virus.”

Indonesia’s approach is also not the only way of restarting the economy. The sooner we protect the most vulnerable, the sooner we can ease restrictions, even if low-risk younger people are not yet immunised.

But the focus on age to reduce deaths, as opposed to “life years gained”, has its consequences.

READ MORE: Antivaxxers are nothing new - but nor are medical cover-ups, so transparency is key

The UK JCVI notes that “the overall risk of mortality for clinically extremely vulnerable younger adults is estimated to be roughly the same as the risk to persons aged 70-74”.

As a result, someone in their 40s with cystic fibrosis or cancer will have to wait until the fourth round of vaccinations, behind over-80s and over-75s.

HeraldScotland: Former carer, Annie Innes, 90, was the first care home resident in Scotland to be vaccinatedFormer carer, Annie Innes, 90, was the first care home resident in Scotland to be vaccinated

Meanwhile, two thirds of people who died with Covid in England and Wales, up to mid-July, had a disability, yet there is no specific prioritisation for this group, who are also less likely to survive into their 80s and 90s (there are no equivalent published figures currently available for Scotland).

This means healthy 65-year-olds, for example, will be immunised ahead of 18-34-year-olds with a learning disability, who are 30 times more likely to die from Covid than their peers.

Only “older” care home residents, not those in care homes for the disabled, are in the 'priority one' tier.

As one campaigner put it to Private Eye in November: “This is the Government clearly stating that even within the same environment, older residents are worth protecting, but disabled residents under 65 can just die.”