UK’s immunity gap — are Strep A and flu rising because of lockdown?

The world was warned

“The immunity gap” was described by Messacar and Baker in The Lancet medical journal as when susceptible individuals avoided infection, meaning they lack pathogen-specific immunity to protect against future infection. Although in the world of viruses, it’s up for debate. 

There has been a devastating surge in Strep A this year from which at least 19 children have tragically died in the UK. 

Group A Strep is a term for bacteria that often causes sore throats. However, some can suffer no symptoms at all. In some cases it can result in scarlet fever — which predominantly affects small children with approximately 90 percent of those ten and under developing the disease. In rare instances, it can lead to an invasive Group A Strep (iGAS) infection which would cause sepsis. 

Dr Nicole Robb, a virologist professor at the University of Warwick and the University of Oxford and co-founder of the health technology company, Picture, said there could be many reasons why we are seeing more cases of Strep A.

She told Express.co.uk: “For instance, people spend more time indoors during cold spells and the bacteria is spread through droplets, for example, coughing, sneezing and talking.

“It can also be that during the last three years we’ve had restrictions on socialising and that not only stops COVID-19 but other common respiratory illnesses like Strep. Measures that were put in place to slow the spread of COVID-19 also reduced the spread of other illnesses. 

“Because less people were infected than usual during this time, this has left a bigger pool of susceptible people after restrictions ended, which is sometimes referred to as ‘immunity debt’.”

Irregular exposure to common diseases do not make immune systems less effective, but that fall in immunity can result in a surge in illness as more people are there to be infected — something Dr Robb believes is playing a role in the winter surge. She added that although immunity debt may play a role in subsequent disease waves, it does not mean that protecting ourselves through lockdowns was a bad idea.