The world recorded 5 reported cases of reinfection.
REPUBLIKA.CO.ID, JAKARTA – People who recover from Covid-19 infection are proven to be reinfected. There are five official cases of new corona reinfection. But this also raises new questions, how does immunity function against SARS-CoV-2?
The latest case of being infected with Covid-19 for the second time several months after recovering, was reported to be a 25-year-old man from Washoe County, Nevada, United States (US). In a span of 48 days, he twice tested positive for two different strains of SARS-CoV-2 infection.
Previously, April 2020 tested positive for the first time for Covid-19. The second Covid-19 infection was reported in June. The second infection triggers symptoms faster and is more serious than the first infection.
The patient reported high fever, headache, cough, dizziness, nausea and diarrhea. After that, he was immediately rushed to the hospital.
In the 48 days between the two Covid-19 infections, the patient underwent two tests and the results were negative. He has now been declared cured again and has returned from the hospital.
Research results published in scientific journals The Lancet – Infectious Disease“It is the fifth officially documented case of Covid-19 re-infection in the world. The other four cases of re-infection occurred in Belgium, the Netherlands, Hong Kong and Ecuador.
Questions regarding immunity
Although there are only five official global cases of SARS-Cov-2 reinfection, the researchers estimate that there are similar cases without symptoms. Researchers admit that much remains unknown regarding SARS-Cov-2 virus infection, as well as how the immune system reacts.
“But our results show an indication that those who are already infected with Covid-19 are not absolutely protected from future infections,” said Mark Pandori, from the Nevada State Public Health Laboratory at Nevada University, the study’s lead author.
This finding is individual and not a general phenomenon. Further research is still needed for this theme. However, the possibility of reinfection of Covid-19 in some patients has a major impact on understanding immunity. Especially when there is no potent and effective vaccine.
Infected with two different strains
Analysis by
Scientists analyzed the genomes of virus samples from patients in Nevada. The results showed significant genetic differences. “This clearly shows that the patient was infected twice by two different strains of the SARS-CoV-2 virus,” conclude the investigators.
In the other four cases, only the patient in Ecuador showed severe Covid-19 symptoms at the first infection. “ We need more research, to understand how long the immunity of people exposed to SARS-CoV-2 lasts? And why the other second infection, although the cases are rare, the symptoms are much more severe, ” said the main researcher Pandori.
So far, there are only a handful of official cases of Covid-19 reinfection. However, that does not mean there are not many cases, because there are also many cases of corona virus infection without symptoms.
“At the moment, we can only speculate about the cause of reinfection,” said the researcher from Nevada University.
Various Hypotheses
Considering the severe symptoms of reinfection cases, the investigators draw several hypotheses. Patients are likely to be infected with a very high viral load, so that in cases of second infection it triggers a much stronger immune reaction. Or the second infection occurs due to a more virulent strain of the virus.
The next hypothesis is what is called Antibody-Dependent-Enhancement (ADE), where the virus actually uses the immune system to infect the organism more massively and stronger. This was observed in the case of infection with the Beta-Coronavirus SARS-CoV.
Mechanically, antibodies amplified by infection bind to the surface of the virus, but do not fight it. On the contrary, it helps the virus to be better received by the body’s cells. That way the virus reproduction is encouraged.
Another possibility, although small, is also a consideration for researchers in the US, namely continuous infection. This triggers activation and deactivation of the virus. This can happen if the SARS-CoV-2 virus that triggers Covid-19 mutates, at a rate that is not as fast as the mutation of the influenza virus.
There is also a possible explanation, the patient was infected with both strains of the virus simultaneously. In the April test, the second strain was not traced because the first strain was very active. Meanwhile in June, the second strain got stronger and the April strain was very weak.
The researchers admit that they do not yet have the ability to carry out analyzes and assessments of the body’s immune reactions or their efficacy in the first case of infection. As for the second case of infection, they can fully assess the immune system’s answer.
Meanwhile, immunologist Akiko Iwasaki from Yale University, USA who was not involved in the study wrote a comment: The more cases of reinfection are known, the better because the scientific similarities can be known, such as how body protection functions and how often natural infections with SARS-CoV- 2 affects the degree of immunity.
source: https://www.dw.com/id/terbukti-orang-bisa-terinfected-ulang-covid-19/a-55617637
sumber : DW
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