코로나바이러스는 새로운 것이 아닙니다. 이것들은 세계에서 가장 오래된 것으로 오랫동안 인간들 사이에서 감기를 일으키는 것으로 알려져 있습니다. 그러나 최신 변종인 'SARS-CoV-2'는 현재 뉴스에서 Covid-19 전염병은 새로운 것입니다.
Often, common cold (caused by 코로나 바이러스 및 기타 바이러스 리노바이러스와 같은) 독감과 혼동됩니다.
독감과 감기는 증상이 비슷하지만 바이러스가 전혀 다르다는 점에서 다릅니다.
Flu or influenza viruses have a segmented genome which cause antigenic shift which occurs due to recombination among viruses of the same genus, thus changing the nature of the proteins on the viral surface responsible for generating immune response. This is further complicated by a phenomenon called antigenic drift which results from 바이러스 accumulating mutations (change in its DNA 구조) 일정 기간 동안 표면 단백질의 성질을 변화시킵니다. 이 모든 것이 장기간 보호할 수 있는 백신을 개발하는 것을 어렵게 만듭니다. 수백만 명의 목숨을 앗아간 1918년 스페인 독감의 마지막 대유행은 독감이나 인플루엔자 바이러스에 의해 발생했습니다. 이것은 코로나바이러스와 다릅니다.
Coronaviruses, responsible for causing Common cold, on the other hand, do not possess a segmented genome hence there is no antigenic shift. They were minimally virulent and occasionally lead to death of the affected people. The virulence of 코로나 바이러스 is normally limited to cold symptoms only and rarely made anyone seriously sick. However, there were some virulent forms of 코로나 바이러스 in the recent past, namely SARS (Severe Acute Respiratory Syndrome) that appeared in 2002-03 in Southern China and caused 8096 cases, resulting in 774 deaths in 26 countries and MERS (Middle East Respiratory Syndrome) that appeared 9 years later in 2012 in Saudi Arabia and caused 2494 cases, resulting in 858 deaths in 27 countries1. However, this remained endemic and disappeared relatively quickly (within 4-6 months), possibly due to its less virulent nature and/or by following proper epidemiological procedures for containment. Hence, no need was felt at that time to invest heavily and develop a vaccine against such a 코로나 바이러스.
최신 다른 of 코로나 바이러스소설 코로나 바이러스 (SARS-CoV-2) seems to be related to SARS and MERS2 which is highly infectious and virulent in humans. It was identified first in Wuhan China but soon became an epidemic and spread across the world to take the form of pandemic. Was this rapid spread across select geographies solely due to the high virulence and infectivity caused by changes in the genetic constitution of the 바이러스 or possibly due to lack of timely epidemiological intervention by reporting to the concerned national/transnational authorities which prevented timely containment measures, thereby causing about a million deaths so far and bringing the world economy to the grinding halt.
This is the first time in the human history that the existing 코로나 바이러스 reportedly underwent changes in its genome that made it into a highly virulent variant, responsible for the current pandemic.
그러나 무엇이 SARS-CoV-2를 그토록 치명적이고 전염성이 있게 만드는 그러한 급격한 항원 드리프트를 일으켰을 수 있습니까?
SARS-CoV-2의 기원을 가리키는 과학계에서 여러 이론이 돌고 있습니다.3,4. Proponents of man-made origin of the 바이러스 believe that the genome changes seen in SARS-CoV-2 would take am extremely long period of time to develop naturally, while other studies argue that it may be of natural origin5 왜냐하면 인간이 창조한다면 바이러스 artificially, why would they create a sub-optimal form that is virulent enough to cause a severe disease but binds sub-optimally to the human cells and the fact that it was not created using the backbone of the known 바이러스.
Be as it may, the fact of the matter remains that a certain almost innocuous 바이러스 underwent genetic changes to transform itself to become mildly virulent SARS/MERS, and finally into a highly infectious and virulent form (SARS-CoV-2) in a span of 18-20 years, appears unusual. Such drastic antigenic drift, which incidentally has a continuum in between, would be highly unlikely to happen in a normal course, in the laboratory of Mother Earth, in such a short time duration. Even if it were to be true, what’s more perplexing is the environmental pressure that would have triggered such a selection in the 진화?
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참조 :
- Padron-Regalado E. SARS-CoV-2용 백신: 다른 코로나바이러스 변종으로부터의 교훈[인쇄물에 앞서 온라인 게시, 2020년 23월 XNUMX일]. Dis Ther 감염. 2020;9(2):1-20. doi: https://doi.org/10.1007/s40121-020-00300-x
- Liangsheng Z, Fu-ming S, Fei C, Zhenguo L. 2019년 신종 코로나바이러스의 기원과 진화, 임상 전염병, 71권, 15호, 1년 2020월 882일, 페이지 883–XNUMX, DOI:https://doi.org/.1093/cid/ciaa112
- Morens DM, Breman JG 외 2020. COVID-19의 기원과 중요한 이유. 미국 열대 의학 및 위생 학회. 온라인 이용 가능: 22년 2020월 XNUMX일. DOI: https://doi.org/10.4269/ajtmh.20-0849
- York A. 신종 코로나바이러스가 박쥐에서 날아가나요? Nat Rev Microbiol 18, 191(2020). DOI:https://doi.org/10.1038/s41579-020-0336-9
- Andersen KG, Rambaut, A., Lipkin, WI et al. SARS-CoV-2의 근위 기원. 냇 메드 26, 450-452 (2020). DOI: https://doi.org/10.1038/s41591-020-0820-9.
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