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 ترجم محتوى الصفحة الى الانكليزية باستخدام خدمة كوكول - الموقع غير مسؤول عن الترجمة

Reinfection, herd immunity and the vaccine.

Mohamed Ibrahim Bassyouni
2020 / 7 / 24

The immunity of individuals´-or-a herd derived from recovery from COVID-19 will be a very useful factor in controlling the disease. However, it would not be useful to rely on this possibility without any clear, generalizable supporting evidence.
It is true that the number of known re-infections is so low that it does not constitute important data when compared to the millions of people who have been diagnosed with COVID-19. Either way, these new results should be taken seriously because of their effects on public health.

The possibility of infection again is "alarming" and will have to be taken into consideration when researching a vaccine. We do not know yet, but the general consensus among experts is that recovery from infection is likely to result in subsequent protection. It is clear that if the immunity does not last for long, this has implications for the vaccine. Obviously, if there are, for example, slight changes in the virus that lead us to be able to infect again, they also have effects on the vaccine, so we have to keep that in mind.


Damanhour s fever manager twice had a corona five-week interval between recovery from the first and the second infection, especially since the smear was positive the first time and then it was proven that he recovered from it with a negative smear, but the subsequent smear came in a positive result again.

It is worth noting that the positive smear of the virus is a statement of the presence of the virus´-or-one of its components in the throat´-or-respiratory tract, a physical presence, but it is not necessarily evidence that the virus is in a state of ill patients with the cells of the person carrying it, and this is called the disease carrier, and it is not necessarily infected Get sick.
Positive tests after a short period of recovery are likely to represent continuous excretion of viral RNA, and it should be noted that polymerase chain reaction tests cannot distinguish between a “live” virus and a non-infectious RNA. Even after the virus dies, DNA fragments remain in the cells.

During recovery, the immune system builds up antibodies that fight with the virus and eliminate it. After 3 days have passed, the symptoms will not be found. It was also proven that the test result remains positive even after five weeks of infection and the fact is that the remains and remains of the virus are not the infectious virus.

As for the explanation of the positive smear for two consecutive times followed by a negative smear, it is not an indication that the virus carrier has been infected with it, the presence of the virus may have been a physical presence and did not cause disease and after that the body got rid of it.
It is also possible that the virus in the first positive smear is not the same as the virus that appeared in the smear that appeared after five weeks, because the corona family includes more than one member, including Covid-19.
Of course, the cause of the first infection is corona, and the reason for the second infection may be any other respiratory microbe from the common cold:
For example, from virus families
Influenza
Rhinovirus
Coronaviruses
Parainfluenza
Metapneumoviruses
RSV
Bacteria
M. pneumoniae
C. pneumoniae
S. pneumoniae
H. influenzae

A third possibility is that the patient may have grabbed the second injury before the completion of defensive protein formation from the first time.
The possibility that the first stroke virus could mutate into a new viral code that is not recognized by the immune system and allows the second stroke, cannot be ignored.

After it was reported that more than 100 patients in South Korea had been diagnosed with COVID-19 for the second time, opinions were divided on what this could mean in the long run.

When it comes to the issue of immunity and COVID-19, research conducted by China last month showed that between 3-14% of coronavirus patients were found to be infected for the second time after being quarantined. Recently in South Korea, 111 people were tested positive for the second time, according to the Korean Centers for Disease Control and Prevention (KCDC).
While more epidemiological investigations are underway, some believe that the condition is not "infected again" but rather that "the virus has been revitalized" in patients.

When it comes to other strains of the coronavirus, it has been observed that infected patients produce antibodies that give them immunity from months to years. But data related to COVID-19 is still very-limit-ed just months after the current coronavirus outbreak.

Hopes are diminishing that "herd immunity" could help eradicate a coherent global epidemic, amid growing concerns that people can be infected with COVID-19. Experts agree that allegations of recurrence of infection require further study given that we are still only months away from the health crisis. But if it is proven that recovered patients can "catch" the virus again, this will affect their own immunity while also complicating efforts to obtain effective vaccines.
Recovery from the disease provides antibodies to fight the infection. However, the shelf life of these antibodies may be insufficient to protect the patient for a very long time´-or-to enhance long-term immunity in the population.

Experts warn that only a few months will pass since the first increase in cases in China and around the world. The frequency and severity of re-infection will not be known until cases rise in areas where there were a large number of infections last winter. We have months to know if re-infection is possible´-or-an important problem.


Work on other coronaviruses has shown that people are more likely to contract again after a year like people who have never been infected. Studies have shown a decrease in COVID-19 antibodies in all patients after two months and has become negative in a high proportion of patients.

In London, King s College researchers found that antibodies peaked up to three weeks after symptoms appeared before depression. A study of 90 patients and health care workers was published in a -print-ed paper in medRxiv and has not yet been subjected to a rigorous peer review.
But research supports the possibility that COVID-19 can repeatedly infect people. Blood tests revealed that although 60% of people provided a "strong" response to antibodies while fighting the virus, only 17% maintained this activity after three months.

Individual natural immunity has proven to be a key factor in vaccine development, so lack of protection after recovering from COVID-19 can make the vaccine process more complicated. Achieving herd immunity would require injury´-or-vaccination of approximately 75% of the population, a goal that may prove elusive in light of conflicting antibody responses and levels of fading.
This raises important issues in the future when we start vaccinating the population. Possibly, we will need an enhanced dose to boost immunity. We definitely need more data and more studies to confirm this result.
Accuracy of the test is still a problem. A group of federal lawmakers sent a letter this week to the US Food and Drug Administration Commissioner worried about low COVID-19 reliability standards. Legislators said: "While no diagnostic test will be 100% accurate, these lower criteria for determining reliability ... may influence our understanding of the prevalence of COVID-19 within society and across the United States."

Efforts to end the epidemic remain dependent on three approaches - public health strategies such as face covers, hand washing, physical expulsion, improved medical treatments, and the drive to develop an effective vaccine. The latest findings on antibody and immunology highlight the need to pursue public health strategies as a basic approach until other effective options are available.





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