“Immunity gap” has developed

Lockdowns cut levels of milder, less transmissible viruses

Lockdowns cut levels of milder, less transmissible viruses and created an "immunity gap"

Interesting article in The Times over the weekend, explaining that whilst the lockdowns were effective at keeping Covid at bay, they were even more effective at cutting levels of milder, less transmissible viruses, and an “Immunity gap” has developed. Flu virtually disappeared in the winter of 2020-21. And although last winter we had been living without lockdown restrictions for six months or so, flu and other viruses were not “seeded” again, so never got going.

David Matthews, professor of virology at Bristol University told the newspaper: “Over the past two winters, there hasn’t been much RSV or flu. And there hasn’t been much rhinovirus, which is the whole smorgasbord of common cold viruses. People’s immune memory has faded.”

The population in general were also much more cautious last winter, particularly with the arrival of the Omicron Covid variant in late November, which led to many Christmas parties being cancelled. “Your immune memory is key to any hope of batting away a virus without you noticing it,” Matthews said. “Your antibodies and T-cells fight the virus off before you feel ill. But what is happening now is that your immune memory has drifted off. It’s taking longer for our immune systems to build an effective response when we get infected — and that time gap means that viruses have more time to do more damage and make you feel ill.”

Dr Michael Carter, a paediatric intensive care doctor and lecturer at King’s College London, agrees that this is the most likely explanation for the surge, and not just in the lungs. “If you have a nasty influenza infection, and you happen to have group A streptococcus around your ears or in your throat, then it’s more likely to be able to get into the bloodstream.”

Immunity gap does not need to be filled

Some doctors are uncomfortable with the characterisation of an “immunity gap” because it might imply the gap needs to be filled. Carter fears some parents might try to infect their children, as they did at “chicken pox parties” in the past. “You shouldn’t do that. Children will be exposed to viruses as they go through their childhood. It hasn’t happened over the past couple of years but children are mixing again now and it will happen naturally.”

The other method of exposure, of course, is immunisation. Children aged two to 11 are eligible for a flu vaccine. Vaccines for RSV are not yet routinely available, though they are in trials.

As for group A strep, vaccination is some way off. Professor Adam Finn, a paediatrician in Bristol and member of the government’s Joint Committee on Vaccination and Immunisation, said a vaccine was badly needed. “There have been some efforts over a prolonged period but, overall, it is neglected because — notwithstanding all the attention it is getting this week — this is not an organism that gets much attention in wealthy countries.

Full article here

COVID-19 in Madeira: updates can be found in an earlier post

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