Difference Between SARS-CoV and SARS-CoV-2: Viral Characteristics and Transmission
What is the Difference Between SARS-CoV and SARS-CoV-2?
Understanding SARS-CoV and SARS-CoV-2
The pandemic that has reshaped the world since late 2019 is primarily attributed to the virus SARS-CoV-2, which causes the disease COVID-19. However, it is important to distinguish between SARS-CoV and SARS-CoV-2, two very different viruses with distinct characteristics and transmission patterns.
The Family of Coronaviruses
Coronaviruses belong to a family named after the crown-like spikes on their surface, CORONAVIRIDEAE. SARS-CoV and SARS-CoV-2 are both part of this family, but they differ significantly in terms of their genetic makeup and the diseases they cause.
SARS-CoV-2 vs. SARS-CoV
SARS-CoV-2: This is the virus that has caused the coronavirus disease 2019 (COVID-19). It was first identified in 2019 and has become a global health crisis. It is more contagious than the previous SARS-CoV and less lethal, having a fatality rate lower than SARS but higher than the flu.
SARS-CoV: This is the virus responsible for Severe Acute Respiratory Syndrome (SARS), which first appeared in 2002. It was more deadly than SARS-CoV-2 but less infectious. SARS was contained, and there have been no new cases since the initial outbreak.
Genetic Differences and Polymerase Recognition Sites
A key difference between SARS-CoV and SARS-CoV-2 is found in their genetic sequences. The genome of SARS-CoV-2 includes a polybasic furin cleavage site PRRA, not present in the original SARS virus. This site is crucial for the virus to enter host cells efficiently.
The emergence of the PRRA site in SARS-CoV-2 raises questions about its origin. Was this a natural mutation, or did it arise from human manipulation in Gain-of-Function (GOF) research? These questions highlight the importance of understanding viral evolution and the potential risks associated with such research.
Transmission Patterns and Impact on Public Health
The spread of SARS-CoV-2 primarily occurs through respiratory droplets when infected individuals sneeze, cough, or talk. The virus is contagious even before symptoms appear, with asymptomatic carriers playing a critical role in its transmission. In contrast, SARS-CoV was less infectious but more deadly, leading to more severe outbreaks.
To control the spread of SARS-CoV-2, public health measures have been implemented worldwide, including social distancing, mask-wearing, and vaccinations. The global Key Readiness and Reaction Plan for Coronavirus aims to suppress the transmission of the virus and prevent related deaths and disease.
Conclusion
Understanding the differences between SARS-CoV and SARS-CoV-2 is essential for effective prevention and control strategies. The higher contagiousness and lower lethality of SARS-CoV-2 compared to SARS-CoV highlight the need for continuous surveillance and public health interventions. Future research will continue to unravel the mysteries surrounding these viruses and inform our response to potential future pandemics.