Why Anti - Inocation vaccines COVID-19 have limited effect?

While discussions about additional doses of vaccines are boiling, what is known for the length of immunity to COVID-19 is still being explored.

Immmmological studies have documented a steady decline in antibodies levels in vaccinated individuals.

The long-term approach of participants in vaccine tests revealed a growing risk of so - called advanced infections and health data from countries such as Israel, the United Kingdom and other countries with high levels of vaccines, indicate that COVID-19 vaccines are losing their power, at least when it comes to fighting the spread of infection. Why?

In the example of Pfizer vaccine, efficiency is stronger by 92.2 percent, between a week and two months after taking second doses. In time, efficiency declines by 6 percent every two months, according to a study involving more than 44,000 people from the United States and other countries. After four to six months, efficiency is estimated at 84 percent”, Pfizer Chief Executive Officer Albert Bourla has broadcast American television network CNBC.

“We have seen data from Israel on the decline of immunity and statistics showing 100 per cent decline in protection against hospital stays. After six months, it falls to 90 to 80 percent”, said Bourla, adding that the company is convinced that the third dose will again increase immunity against Delta version.

Israel has implemented the fastest vaccine programme in the world since mid-December 2020. Nearly 6 million out of a total of 9.3 million people received at least one dose of Pfizer, while nearly 2.2 million received a third dose in late August. At that time, however, an increase in the number of infected began to be recorded.

How do vaccines work?

Many scientists have said that it is not uncommon for the efficiency of vaccines to drop over time.

In the case of COVIED-19, it has become clear over time that antibodies taken through the weaker inoculation know the variants of the SARS-Cov-2 virus compared to the original type that causes pandemic.

A nurse administers a dose of the Saniago vaccine for the Coronavirus in Chile on June 3, 2021.

However, it remains unclear to what extent and whether the immune system's defense mechanisms that protect people vaccinated from serious forms of disease, hospitalization and death also fall.

“Things are getting dim, but not equally”, says Nicole Doria-Rose, an immunologist at the National Institute of Allergy and Infectious Diseases in Bethesda, in the state of Maryland, writes Nature magazine.

The sub-x0.0... The level of these molecules usually grows after the vaccine, and then it decreases rapidly over the later months. That's how vaccines work, notes Doria-Rose.

Life expectancy of immune cell response

But the answers to cell immunity are long - term. Jennifer Gommerman, an immunologist at the University of Toronto in Canada, explains: “the cell community will protect you from diseases”.

B memory cells, which can quickly apply more antibodies in case of repeated exposure to the virus, tend to be maintained, including T cells, which can attack already infected cells. Cells B and T provide an additional measure of protection, if SARS-CoV-2 passes through the body's first line of defense, Nature magazine explains.

When the threat of body infection passes, the immune response decreases B and T cells should no longer be willing and they begin to die. The level of antibodies, which is the easiest to measure, falls over several months until it is levelled.

These body processes are normal, said the journal The Atlantic, Deepta Bhattacrya, an immunologist from Arizona University.

“First you have a big rise and then a drop”, Bhattcharya said.

The reason for this is that if the organism does not reduce its immune response to any pathogen that it faces and continues to collect antibodies, it would have been detonated for a long time.

In addition, trying to maintain such a large immune reservoir would require a lot of energy. And I don't even know where to keep all of those <x1 cells, says Marion Pepper, an immunologist at Washington University.

Antibody levels will drop in months after the vaccine or infection, but that doesn't mean they will drop to zero, Bhattacharya said. Even though most B cells die, some remain in bone marrow and release molecules that fight at more modest levels viruses but still at levels that can be marked.

Mymune cell memory

Although long - lived B cell life may change, some studies have suggested that these cells are capable of surviving for decades as antibodies factories. Other immune cells, B memory cells, circulate throughout the body as sleeping agents ready to continue producing antibodies whenever necessary.

All these B cells can continue to expand and increase their ability to destroy the virus for months after vaccine or pathogen leaves the body in an accelerated form of developing antibodies.

“The quality of body antibodies improves over time”, has stressed Bhattcharya for The Atlantic newspaper. “You need much less of them to protect”, he stressed.

In one of the long - term studies, which has simultaneously examined three pillars of the immune system, B cells and T cells found that the vaccine stimulates stable cell immunity.

The number of B memory cells continues to rise for at least six months, and in time they become better at fighting the virus. The number of T cells remains relatively stable.

So you have this reserve”, says John Wherry, an immunologist at the University of Pennsylvania Medical School in Philadelphia, who conducted the study.

<x) / REL/