Opposition politicians have been asking questions about the speed of vaccination roll-out. For the next few months, it will be inhibited more by supply than by organisational delays.

Once the healthcare workers and care home residents have been vaccinated, perhaps by the end of March, a far more important phase in the battle with the virus will begin.

Supply should become more plentiful, but the willingness of people in the middle and younger age groups to take the jab will really matter.

No comprehensive reopening of the economy is prudent until a minimum level of immunity in the population has been achieved.

This could require 70% or possibly 80% of adults to accept vaccination, and surveys around Europe have revealed two forms of resistance, strongest in younger age groups.

The first comes from anti-vaxxers, some of whom believe that the vaccine itself is damaging, others that it is part of a conspiracy to take over the world. Protestors outside the Department of Health on Dublin’s Baggot Street last week had banners proclaiming that “Vaccines cause autism”.

He was struck off the register after an inquiry by the British Medical Council in 2010

They do not – no connection has ever been established and immunologists have been battling this contention since it was first promoted by Andrew Wakefield, an English medic, in 1998. He claimed to have evidence, which turned out to be fraudulent, that the MMR vaccine caused autism.

He was struck off the register after an inquiry by the British Medical Council in 2010 and has resurfaced in the US on the far-right think-tank circuit.

The conspiracy theory is that both COVID-19 and the vaccines have been created by a secret group with designs on world domination. The composition of the group mutates.

A recent version lists the membership as Microsoft billionaire Bill Gates, the Freemasons, Big Pharma, George Soros, the Vatican and the Chinese Communist Party.

Wait-and-see

A more serious threat to a successful vaccination programme in European countries, including Ireland, is people displaying vaccine hesitancy, which is not so hard to understand.

If you are a young adult with no medical conditions, hence a low risk of serious illness or fatality, why take the chance on vaccination with possible side-effects?

Failure to convert at least some of this group could compromise the overall programme

This is the wait-and-see stance adopted by around one-third of the public in many surveys.

Failure to convert at least some of this group could compromise the overall programme.

It is not irrational, if you believe that the jab brings some risk of side-effects, to duck out, especially if you are not afraid of catching the virus – almost all younger people recover from the infection without hospitalisation. But there is much more disease about right now, especially in Ireland, and a high risk of catching it.

There is evidence that even younger patients at small risk of fatality may not recover fully or quickly if they catch the virus.

It is not a good idea to catch COVID-19 whatever your age and vaccination, if it works at all, should be a help

This is so-called ‘Long Covid’ – studies in medical journals have reported serious symptoms in recovered patients of all ages three and six months after initial diagnosis and treatment, including fatigue, lung impairment and kidney problems.

Some British studies have found that up to 10% of younger patients not requiring hospitalisation have had headaches, breathing problems and other ailments sufficient to keep them out of work for months. It is not a good idea to catch COVID-19 whatever your age and vaccination, if it works at all, should be a help.

Side effects

But what about the side-effects of vaccination? If you are in a low-risk group, you avoid the small risk of serious illness and the higher risk of Long COVID, but at the cost of any side-effects of the jab itself.

The randomised controlled trial is the staple methodology in the approval of medicines, including vaccines.

For the Pfizer/BioNTech vaccine, it worked like this – the vaccine was administered last summer to thousands of volunteers and a harmless but identical jab was given to the same number of people in a control group.

None of the participants knew whether they had been given the real vaccine or a placebo

The two groups were representative on characteristics like age, gender and medical history, and were drawn from several countries and ethnicities.

None of the participants knew whether they had been given the real vaccine or a placebo and they went back to their normal routines.

They were then tested for COVID-19 at regular intervals in subsequent months and some of them eventually tested positive.

Statistical validity

With just over 18,000 in both groups, 170 people tested positive before the trial was deemed adequate for statistical validity.

If the vaccine had been a total failure, the 170 positives would have been equally distributed, 85 each, across the vaccinated and the unvaccinated (placebo) groups.

There was also no evidence, from the 18,000 people vaccinated, of side-effects beyond a sore arm and a brief headache

In the event 162 positives were in the unvaccinated group, while just eight had received the vaccine.

The vaccine developers declared a success and the regulators agreed. There was also no evidence, from the 18,000 people vaccinated, of side-effects beyond a sore arm and a brief headache – not one serious illness attributable to vaccination, and the chances of catching the virus are miles below the probability if you pass it up.

Work out the odds for yourself.