Yes, Covid shrinks our brains

This isn’t particularly worrisome, but hospital admissions are up 12pc. Cases are particularly increasing in people over the age of 55, which is worrisome, given that the risk of severe illness increases with age.

There are three possible reasons for this increase in the UK, and these also apply to us, so we need to be on the lookout.

First, the more contagious variant of Omicron, known as BA.2 is becoming dominant and infecting more people, some of whom can develop severe disease. In Hong Kong, where cases are increasing rapidly, BA.2 is causing serious illness in unvaccinated people.

Second, there is evidence that vaccine effectiveness is declining in older age groups. In the UK, there will be an incentive in April to give all over-75s a fourth shot.

A third possible reason is what is called “unshielded”. The people who have been extremely careful over the past two years are rightly emerging back into the world, but it is a world where infections are still common. They have immunity from vaccination, which will protect them from serious illness and death. But they are at moderate risk of infection and illness, possibly requiring hospitalization.

Will we see an increase in cases and hospitalizations here? Spring and summer cannot come too soon, because then we will spend more time outdoors. Remember, Covid-19 is mainly spread indoors in crowded places with poor ventilation and no masks. Sound familiar right? We can get lucky and get to the point where good weather will help us.

There may have been a problem during production. Health Secretary Stephen Donnelly said last week Covid-19 had an impact on emergency departments. Let’s hope that the situation does not deteriorate.

All of this is somewhat predictable. Wearing less masks and socializing more in a variety of settings will increase the number of cases. Perhaps more importantly, if people with symptoms are no longer testing for antigens or self-isolating, this means they will be spreading the virus as they conduct their business. We need to remind people that they should still stay home if they have symptoms and a positive antigen test.

And then there was the news last week that Covid-19 can definitely affect the brain, not just the lungs. There is evidence for this, with symptoms such as loss of smell and taste, but also effects on concentration and mental agility being reported since the start of the pandemic.

There is now an explanation for why loss of smell and taste is a feature of Covid-19. A large UK study involving scanning and analysis of people between the ages of 51 and 81 before and after Covid-19 has revealed that a part of the brain called the parahippocampal gyrus is damaged by Covid. -19. This is the first clear evidence that the SARS-CoV-2 virus causes brain damage. It explains why humans lose their sense of smell.

It’s the parahippocampal gyrus that connects to the nerves in your nose to detect what we can smell. Research has shown that this part of the brain shrinks by 1.8pc, which is enough to prevent it from working properly.

More worryingly, a part of the brain called the cerebellum, or gray matter, also showed signs of damage, shrinking by 0.8pc. This may not seem like much, but it is also considered important. That part of the brain shrinks with age, about 0.2pc per year. This degree of shrinkage is therefore four times what would normally occur. The shrinkage is more prominent in older people and those with more severe illness. However, it is still evident in some people with mild or even no symptoms.

Those scanned were given mental skills tests, and lower scores were associated with more shrinkage.

Will the brain recover from this injury? The sense of smell seems to return, which is a hopeful sign. This can also be the case of mental agility. But in some people, symptoms such as a loss of smell and brain fog persist and can be an important part of the long-lasting debilitating effects of Covid. Therefore, there may be a range in which some recover faster than others.

Vaccination has the potential to protect the brain. This is because the job of the vaccine is to train the immune teams to clear the virus and thereby reduce the damage the virus causes.

At a minimum, vaccination should alleviate trauma to the brain and allow it to recover in the majority of those vaccinated.

Therefore, the message remains the same. If you want to reduce your risk of brain damage, especially if you are in a younger age group where vaccination is less common than older adults, get vaccinated. It will protect your brain, the most precious of all organs, as you learn about the world and grow into adulthood.

Now that we’re back in the world again, we still need to be a little cautious, at least until we leave winter behind. You should still wear a mask in crowded places, especially a more protective FFP2 mask if you are vulnerable or older. You can still think twice about being in a crowded place with poor ventilation. If you have symptoms, get an antigen test and stay home if you’re positive.

Cases are increasing in England, Scotland and most seriously in Hong Kong. The reopening is certainly part of this but there is also less immunity due to dwindling vaccines and possibly, in the case of Hong Kong, low levels of natural infection due to the policy. their zero-Covid.

We have some advantages here because of our vaccine uptake and controlled spread of the virus. But we would be wise to embark on our own strengthening campaign among the elderly and continue to promote the vulnerable. They will then have their protection restored.

We’re still in a much better place than we were this time last year, hoping to add in newer vaccines for next winter. Antiviral drugs like Paxlovid, and complementary therapies to treat people who are actually sick with Covid-19, are also increasingly available.

Covid-19 is still a disease you don’t want to get sick of, especially given the latest news about brain damage. But it has mostly become a medical problem rather than a social one. Scientists and doctors will continue to study and monitor it to make sure we don’t go back to the bad old days of Covid-19.

Luke O’Neill is a professor of biochemistry in the school of biochemistry and immunology at Trinity College Dublin