Wales' Covid vaccine data: Can we trust the numbers?

A Vaccine is prepared
The latest figures from Public Health Wales show that 270,833 people have had a first dose of a Covid vaccine Credit: PA

Wales's progress through, and out of, the Covid-19 pandemic is being defined by data.

People are increasingly looking at the numbers - particularly around the vaccine roll-out - to assess how Wales is doing, and when they might get the jab themselves.

The latest figures from Public Health Wales show that 270,833 people have had a first dose of a Covid vaccine in the country.

So far, 8.7% of the population have had a vaccine in the last seven weeks.

The Welsh Government set a target to vaccinate 70% of over-80s and those in care homes by the weekend - but we won't know whether that has been met for a couple days. The health minister said he hoped to give an answer by Wednesday this week.

  • So why do we have to wait?

This is down to a lag in reporting.

GPs and those running vaccination centres need to put their vaccination numbers into the system for them to be reported accurately.

There can be a delay in vaccination data being inputted into the system Credit: PA

It's because they spend all day jabbing arms that it's not always possible to input all the data straight away.

The latest numbers are the vaccinations given - and logged - up to 10pm the night before.

  • Why were there differences between what ministers say and official figures?

Last week, the First Minister said 40% of over-80s had been vaccinated, and the health minister said "the majority" had.

These assertions contradicted subsequent Public Health Wales numbers which showed just 23.9% had been vaccinated.

The discrepancy is because, we're told, ministers were using "operational data". That is information based on vaccines distributed and appointments booked etc. This operational data, unlike that published by Public Health Wales, has not been verified, which is why there was a difference.

Mark Drakeford told ITV News last week he believed around 40% of the over-80s had received the first dose of the Covid vaccine Credit: PA
  • Why didn't ministers make this clear when they used these figures in the first place?

It is clear from conversations ITV Wales has had with Welsh Government that it probably wished there was more context provided when figures were used.

Not adding this extra context led to many questions last week about why the numbers weren't matching up.

Watch to see whether the messaging from ministers changes.

  • So exactly how many over-80s have been vaccinated?

The latest available numbers from Public Health Wales show that 88,005 (48.1%) of over-80s have been vaccinated. It is worth pointing out, though, that many of these may also be care home residents.

The latest numbers show that 11,144 (66.2%) of care home residents have received the vaccine.

  • So, can we trust the numbers?

When all's said and done, the numbers from Public Health Wales are a 'best guess' of how many people in Wales are vaccinated.

Lags in inputting data and possible duplication of people falling into multiple categories are among the reasons why it is in many ways impossible to give an absolutely exact picture.