Around one in six people in Yorkshire and the Humber and London had Covid-19 antibodies in December, new data reveals. 

Figures published by the Office for National Statistics (ONS) on Tuesday show that the level of antibodies for the virus detected across all regions of England increased significantly between November and December.

Estimates drawn from a sample of 20,878 people reveal an average of 5.4m people – 12.1% of the population aged 16 years and over in England – would have tested positive for antibodies in December.

A further 2,000 people took part in the study across Scotland, Wales and Northern Ireland, where fewer people were found to have the antibodies.

The analysis carried out by the ONS is based on blood test results taken from a randomly selected sample of over-16s,

The highest proportion of antibodies amongst the population was found in Yorkshire and the Humber, where 16.8% of people had them.

The south-west recorded the lowest percentage, with 4.9% of participants there found to have antibodies.

Experts have found that it takes two to three weeks for the body to make enough antibodies to fight the infection – but that, once a person recovers, antibodies remain in the blood at low levels and can help protect individuals from getting the same infection again.

However, these antibody levels can decline over time to the point that tests can no longer detect them. Crucially, it is not yet known exactly how long they can remain detectable, meaning we cannot say based on this survey alone how many people have had coronavirus in total since it appeared in the UK.

The ONS analysis provides a breakdown of regions in England, but Wales, Scotland and Northern Ireland are presented only as whole countries. Here’s how many people had Covid antibodies, nation by nation, in December: 

• England – 12.1% of the population aged 16+, equating to 5.4m people (one in eight) 
• Wales – 9.8% of the population aged 16+, equating to 247,000 people (one in 10) 
• Scotland – 8.9% of the population aged 16+, equating to 398,000 people (one in 11) 
• Northern Ireland – 7.8% of the population aged 16+, equating to 115,000 people (one in 13) 

And here’s a breakdown of what the levels of antibodies looked like in England, region by region: 

• North-east – 12.5% of the population aged 16+, equating to 269,000 people 
• North-west – 15.1% of the population aged 16+, equating to 879,000 people 
• Yorkshire and the Humber – 16.8% of the population aged 16+, equating to 735,000 people 
• East Midlands – 12.7% of the population aged 16+, equating to 495,000 people 
• West Midlands – 14.3% of the population aged 16+, equating to 676,000 people 
• East of England – 8.1% of the population aged 16+, equating to 401,000 people
• London – 16.4% of the population aged 16+, equating to 1.16 million people 
• South-east – 8.3% of the population aged 16+, equating to 601,000 people 
• South-west – 4.9% of the population aged 16+, equating to 226,000 people