Why does covid still affect some people?

Why does covid still affect some people?


Scientists specializing in our immune systems warn that Covid is still causing serious infections that could be worse than before and leave us unconscious for weeks.




What is it like to get Covid now? It’s a question I’ve pondered since a friend was amazed at how weakened he was by his illness. The third wave of covid was significantly worse than the previous one.

“I thought every time you get an illness it should be a little milder, right?” was the message she wrote from a hospital bed.

This has certainly been said a lot during the pandemic. But I also know colleagues and people I’ve interviewed or spoken to at the school gates who have been hit hard by Covid in recent months.

Importantly, Covid has always caused a wide range of symptoms. Even before vaccines, some lucky people barely got sick or didn’t even show symptoms.

For some of us, Covid is just a few hiccups, not even enough to make you rummage through the bathroom cabinet to see if there’s a flow test hidden in there.

But scientists specializing in our immune systems warn that Covid is still causing serious infections that could be worse than before and leave us unconscious for weeks.

How we deal with exposure to Covid depends on the battle between the virus itself and our body’s defenses.

The initial stages are crucial because they determine the degree of penetration of the virus into our body and its severity.

However, waning immunity and the evolution of the virus are shifting the needle.

“I feel very weak”



Fewer people will receive a booster vaccine this winter

Professor Eleanor Riley, an immunologist at the University of Edinburgh, had her own “horrific” bout of Covid, which was “much worse” than expected.

He told me: “People’s antibody levels against Covid are probably lower now than they have been since the vaccine was first introduced.”

Antibodies are like microscopic missiles that stick to the surface of the virus and prevent it from infecting our body’s cells.

So if you have a lot of antibodies, they can clear the virus quickly and any infection will be short and mild.

“Now, because the antibodies are lower, a higher dose [do vírus] it is causing a more severe attack of the disease,” says Professor Riley.

Antibody levels are relatively low because it has been a long time since many of us have been vaccinated (if you are young and healthy, you have only been offered two doses and a booster) or infected, which also increases the immunity.

Professor Peter Openshaw of Imperial College London told me: “The thing that used to make a huge difference was the wide and rapid uptake of vaccines: even young adults could be vaccinated.”

The expert says it’s not something “destructive,” but he thinks the result will be that “many people will have a very unpleasant illness that will leave them ‘knocked out’ for several days or weeks.”

“I’ve also heard of people who have had bad bouts of Covid, who are young and in good shape. It’s a surprisingly sneaky virus, sometimes making people sick and occasionally leading to ‘long Covid’,” he says.

He thinks there’s a “good chance” you’re susceptible if you haven’t had Covid in the last year.

The official decision of the British government is to vaccinate those who risk dying from Covid or who require hospital treatment. This relieves pressure on the NHS.

Professor Riley argues: “But that doesn’t mean people under 65 won’t get Covid and won’t feel very unwell.

“I think the consequence of not encouraging these people is that we will have more people out of work for a week, two or three over the winter.”

The decision about who to vaccinate isn’t the only thing that’s changed: The virus is changing, too.

“Low immunity”

Antibodies are highly accurate because they rely on a close match between the antibody and the part of the virus it attaches to. The more a virus evolves to change its appearance, the less effective the antibodies become.

Professor Openshaw said: “The viruses circulating now are immunologically quite distant from the original virus used to make the first vaccines, or which last infected them.

“Many people have very low immunity to omicron virus and its variants.”

If you feel unwell because of Covid – or worse than before – it could be this combination of waning antibodies and the evolving virus.

But that doesn’t mean you’re more likely to get seriously ill or need hospital care.

A different part of our immune system, called T cells, kicks into action when an infection is already underway. They have been trained by past infections and vaccinations.

T cells are less easily confused by mutant viruses, as they detect cells that have been infected by Covid and kill them.

“You get very ill and end up in hospital, but in that process of killing the virus there is collateral damage that makes you feel really bad,” Professor Riley says.

Relying on T cells to kill Covid is what causes muscle pain, fever and chills.

So where does this leave the idea that Covid is on track to becoming a mild, harmless infection?

There are four other human coronaviruses, related to Covid, that cause symptoms of a common cold. One of the reasons they are considered mild is that we get them in childhood and then throughout our lives.

Professor Openshaw makes clear that “we are not there yet” with Covid, but “with repeated infections we need to build natural immunity”.

In the meantime, will some of us have to endure a terrible winter?

“I’m afraid so,” says Professor Riley.

Source: Terra

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