We have read many articles related to the coronavirus in the past few years, and sometimes have even felt bored aboutby it.

have read / have felt　→ parallelism

We have tried many ways to prevent ourselves from being affected including humanby physical isolation, resident lockdowns, and vaccination injections.

Surprisingly, all these efforts couldn't stop the stubborn virus and its variant causfrom making us ill.

Starting fromince last year, nearly all of the countries in the world have gradually ignored the virus and implemented ways to create herd immune waysity.

I got a positive test three days ago and have had mild symptoms with soma little coughing and a low grade fever of 37.5 degrees Celsius for two days.

My wife was bedridden for three days due to the same reason, because I was contagious by herwith the virus.

残念です！お大事に！

As we know, the symptoms vary from different peopleperson to person.

そうですね。

We have read many articles related to the coronavirus in the past years, and sometimes even felt bored about it.

One small stylistic suggestion: when I started reading, I wasn't sure who "we" was - is it you and your wife, or "we" as in people in general? In at least American English, people sometimes like to generalize by writing "we" when they mean everyone, so it's a good idea to be a bit more detailed the first time you use "we" in a text. For example, "My wife and I have read..." or "People have read..." and then everyone knows who the "we" refers to in the rest of the text. :)

We have tried many ways to prevent ourselves from being affected, including human physical isolation, resident lockdown, and vaccination inject.

"Human physical isolation" is not wrong; I usually hear it described as just "physical isolation."

Surprisingly, all these efforts couldn't stop the stubborn virus and its variant causmaking us ill.

"Causing us ill" means more like "causing us terrible/evil things" so if that's what you meant, please disregard my suggestion!
"Making us ill" means "causes sickness in us."

Starting from last year, nearly all countries in the world gradually ignored the virus and implemented herd immune ways.

Starting last year is OK without the "from."
Although "starting from..." seems to imply a present tense, the start was in the past (last year) so the verbs should be in past tense.

I got a positive test three days ago and I have had mild symptoms with some cough and a low fever of 37.5 degrees Celsius for two days.

Because "for two days" implies you have had this condition for the past two days, I suggest changing to the past perfect: "have had."

My wife was bedridden for three days due to the same reason, I was contagious bygot the coronavirus from her.

"to be contagious" is a state of being, whereas "to infect someone" means a person passes a virus onto someone else. If your wife first had the coronavirus, you could say "she infected me" (which is accurate but sounds severe!) or "I got the coronavirus from her." (more friendly-sounding)

As we know, the symptoms vary from differbetweent people.

Or, "the symptoms vary from people to people." Using "different" is not wrong, but I think it's generally understood that one person is different than the other, so it's not really needed. But you can leave it in!

We have read many articles related to coronavirus in the past years, and sometimes even felt bored about it.

In the last few years, many of us have read many articles about coronavirus to perhaps even the point of boredom.

We have tried many ways to prevent ourselves from being affected including human physical isolation, resident lockdown, and vaccination inject.

In attempting to avoid being affected we've tried many things, including isolation from other humans, locking down residents, and injecting ourselves with vaccines.

Surprisingly, all these efforts couldn't stop the stubborn virus and its variant causing us ill.

To our surprise, this virus is stubborn and all these efforts could not stop it or it's variants still causing illness among us.

Starting from last year, nearly all countries in the world gradually ignore the virus and implement herd immune ways.

Beginning last year, almost all countries worldwide have gradually started to simply ignore the virus and rely on herd immunity.

My wife was bedridden for three days due to the same reason, I was contagious by her.

My wife was also positive and as a result was bedridden for three days. She was contagious and I got infected from her.

As we know, the symptoms vary from different people.

As we know, symptoms can vary between people.

We really don't quite care about it now.

We don't really care about coronavirus now.

The reason I am writing this entry is to express my disgust for the terrible virus and I wish that someday the world will discover who created it and where it originated.

I'm writing this entry to express my disgust for this terrible virus. My wish is someday that the world will discover who created it and where it originated.

We have tried many ways to prevent ourselves from being affected including human physical isolation, resident lockdown, and vaccination inject.

My wife was bedridden for three days due to the same reason, I was contagious bycaught the virus from her.

If she got sick because of you, you can say "She caught the virus from me".

The reason I am writing this entry is to express my disgust for theis terrible virus and I wish that someday the world will discover who created it and where it originated.