SARS-CoV-2’NİN SÜREGELEN EVRİMİ: PANDEMİNİN SONUNA NE KADAR YAKINIZ?

Öz

Pandeminin başlangıcından bu yana SARS-CoV-2 genomunun dizilenmesi, viral evrimin anlaşılmasına katkıda bulunmakta ve COVID-19 hastalığının kökenleri ve yayılmasına yönelik genomik epidemiyoloji araştırmalarına olanak sağlamaktadır. SARS-CoV-2, diğer RNA virüslerine benzer şekilde sürekli mutasyona uğramakta ve yeni varyantlar ortaya çıkmaktadır. SARS-CoV-2 varyantları arasında, bunların yalnızca bir kısmı, daha bulaşıcı oldukları ve daha ağır hastalıklara neden oldukları için halk sağlığı açısından risk oluşturabilmektedir. Bu mutasyonlar virüse seçici bir avantaj sağlayabilirler. Varyantlar insan sağlığı açısıdan daha riskli hale geldiğinde, endişe verici varyantlar (VOC) olarak adlandırılmaktadırlar. 2021 yılının Kasım ayına kadar pandeminin hâkimi olan Delta varyantı, hastaneye yatış ve ölüm riskinin artmasına neden olmuştur, ancak mevcut aşılar bu varyanta karşı etkilidir. Son varyant olan Omicron, artan bulaşabilirlik ve azalmış antikor duyarlılığı ile karakterize edilmektedir. Bu derlemede, SARS-CoV-2 varyantlarının bulaşıcılıkları, hastalığın şiddeti ve bağışıklık duyarlılıkları ile ilgili bilgiler incelenecektir.

Anahtar Kelimeler

• COVID-19
• SARS-CoV-2
• Varyant
• Mutasyon

THE CONTINUOUS EVOLUTION OF SARS-CoV-2: HOW CLOSE ARE WE TO THE END OF THE PANDEMIC?

Öz

Sequencing the SARS-CoV-2 genome since the onset of the pandemic has contributed to the understanding of viral evolution and has enabled genomic epidemiology investigations into the origins and spread of COVID-19 disease. Similar to other RNA viruses, SARS-CoV-2 is constantly mutating and new variants appear. Among the SARS-CoV-2 variants, only some of them pose a public health risk because they are more contagious and cause more severe diseases. These mutations can give the virus a selective advantage. When variants become more risky to human health, they are called variants of concern (VOC). The Delta variant, which dominated the pandemic until November 2021, has resulted in an increased risk of hospitalization and death, but current vaccines are effective against this variant. The last variant, Omicron, is characterized by increased transmissibility and decreased antibody sensitivity. In this review, information about the contagiousness of SARS-CoV-2 variants, the severity of the disease and their immune susceptibility will be examined.

Anahtar Kelimeler

• COVID 19
• SARS-CoV-2
• Variant
• Mutation

Kaynakça

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