Omicron and Long Covid

Long Covid and Omicron

SARS-CoV-2 can spread from cell to cell through cell walls. This is a way of hiding from the immune system. This ability was limited in SARS-CoV-1. SARS-CoV-1 leaves the infected cell and infects new cells through receptors. This is the classic way. This leaves the virus more vulnerable to immune system attacks and antibody neutralization. This feature of SARS-CoV-2 is very important in terms of hiding it from the immune response..

Variants from SARS-CoV-2 and SARS-CoV-2 use ACE2 and TMPRSS2 receptors to infect cells. However, with the Omicron BA.1, this situation has changed. TMPRSS2 is an abundant receptor in the lung. Omicron has a lower affinity for the TMPRSS2 receptor than other variants.( 5 times less than Delta). This explains why Omicron BA.1 has less lung pathogenicity than Delta.

In addition, Omicron can enter the cell directly by the endosomal route without ACE2 and TMPRSS2. This ability was almost non-existent in previous variants.

And Omicron's affinity for the ACE2 receptor is high compared to other variants. The ACE2 receptor is abundant in the upper respiratory tract. This is one of the points that helps explain the question of why Omicron is so contagious.

There are other organs and systems in our body that contain plenty of ACE2 receptors. These are the targets of Omicron, which has a high affinity for the ACE2 receptor, in our body. This shows us the risk that Long-Covid cases may increase with Omicron BA1.

One of the most serious diseases in Long Covid is nervous system symptoms.

COVID-19 NEUROLOGICAL SYMPTOMS

• 1-)Cognitive Disorders: These are symptoms that are very common in the post-acute covid phase. One of the most obvious symptoms is Brain Fog.

• Cognitive impairment, attention difficulties, poor memory and cognitive decline, brain fog.

• Also, Decreases in neuropsychological test scores have been reported by many articles. •

• 2-) Depressive Symptoms: Depressive symptoms are common in long covid cases (40%)

• Low mood, sleepiness, pessimism, irritability, exhaustion, and decreased appetite

• 3-) Burnout: These symptoms have a rate of 35% in long covid cases. These symptoms begin in the acute covid phase and continue in the post covid phase and show us peripheral nervous system involvement. (Extreme fatigue, asthenia.)

• 4-) Taste-Odor Disorders: It is a neurological disorder that starts in the acute covid period and continues in the post covid period. These symptoms show us the damage of SARS-CoV-2 to the olfactory bulb and the invasion of the gyrus.( Aguzia, anosmia, hyposmia and hypogeusia.)

• 5-) Anxiety Symptoms: It was determined that the average time between the diagnosis of Covid and applying to rehabilitation services was 93 days. That is, the neuropsychiatric symptoms in Long Covid cases proceed in secret. These symptoms were detected with a rate of 23% in Long Covid patients.

• 6-) Sleep Disorders and Insomnia: Symptoms in this group were seen in 437 of 1655 Covid patients examined in a study. These are a common Post-Covid symptom and It is known that these symptoms continue even 6 months after the diagnosis of infection.

• 7-) Myalgia: Myalgia is a disease that reduces quality of life and it has a rate of 21.4% in Long Covid cases.

• 8-) Paresthesia: Paresthesia is a Long-Covid symptom. In about five studies, the rate of this disease in long covid cases was determined as 16%.

• 9-) Hearing Problems: Hearing problems are a reported Long covid symptom in Long covid cases. (Vestibulocochlear neuritis, tinnitus, sudden hearing loss.)

• 10-) Status Epilepticus and Epileptic Seizures: These symptoms were detected less in long covid cases.

• 11-) Eye Problems: These symptoms were detected in a low rate (7%) of Long Covid cases. (Diplopia etc).

• 12-) Psychiatric Symptoms: The incidence of these symptoms in Long Covid cases is low. (Psychosis, paranoia and hallucinations)

The increased ACE2 affinity of Omicron, its ability to infect cells via the endosomal route and its ability to hide from the immune system by cell-to-cell transmission show us the risk of increasing Long Covid cases.

I'm asking a question here. Could Omicron's ability to hide from the immune system by cell-to-cell transmission protect it from immune response? Could this be the reason for the increased rate of reinfections in Omicron cases?

Answering this question is very important. Because reinfections are on the rise and the BA.2 wave is approaching.

The Delta Variant was a successful variant in suppressing the interferon defense of the lungs. On the contrary, Omicron BA.1 has an effect that increases the interferon defense of the lungs and Omicron's affinity for the TMPRSS2 receptor is lower than Delta. For this reason, the pathogenicity of Omicron BA.1 is relatively low compared to Delta.

There is a risk here: SARS-CoV-2, which has decreased affinity for the TMPRSS2 receptor with Omicron BA.1, may increase its affinity for the TMPRSS2 receptor with another variant. If this happens with a sub-variant of Omicron, the new variant may be both highly contagious and more pathogenic.

Most likely, this happened with the BA.2 and BA.2.2 variants. The BA.2 variant has a higher affinity for the TMPRSS2 receptor than BA.1. This shows us that BA.2 may be more pathogenic than BA.1. Researches and epidemiological data from countries under the influence of BA.2 wave also point to this.

• Denmark was one of the first countries to experience the BA2 wave, and they lifted all Covid measures during the BA2 wave. And unfortunately, Covid deaths increased a lot in the BA.2 wave in Denmark

• Hong Kong is one of the countries that experienced the BA.2/BA.2.2 wave. Very high case numbers and unfortunately very high Covid deaths are reported in Hong Kong.

• Death rates and hospitalizations were lower during the BA.1-BA.1.1 wave in South Korea than during the BA.2 wave and now, as the BA2 rate increases in South Korea, the hospitalizations and death rates increase compared to the BA.1 wave.

• Hospitalization and death rates in the BA.2 wave started to be higher than the BA.1 wave in England, Scotland, Austria, Norway, Ireland and many other countries and unfortunately continues to increase.