Why does SARS-CoV-2 spread so easily?
On 13.07.2020, the National Institute of Public Health informed us that at a global level there are 12,698,995 confirmed cases of SARS-CoV-2 infection, of which 564,924 deaths. Significant increases in the number of cases were recorded in the United States, Great Britain, Sweden, Saudi Arabia, Pakistan, India, Bangladesh, Mexico, Brazil, Chile, Peru, and Russia.
A. What structural characteristics of the SARS-CoV-2 virus allow it to attack human cells and spread so efficiently?
In an effort to understand the nature of this highly contagious virus, researchers made comparisons with the SARS coronavirus (SARS-CoV) – the causative agent of severe acute respiratory syndrome, better known as SARS.
SARS-CoV and SARS-CoV-2 share 86% of the same genomic sequence. SARS was considered the "first pandemic of the 21st century" because it spread rapidly from continent to continent, causing over 8,000 infections in about 8 months, with a case fatality rate of 10%. However, SARS-CoV-2 spreads much faster.
B. What makes the new coronavirus so infectious?
We are taking a look at some of the most recent evidence that helps answer this question. Several genetic studies have investigated the microscopic structure of the virus and have discovered a key protein on its surface which, together with a receptor on human cells, explains why the virus can attack and spread so easily.
Previous research has revealed that this type of virus invades cells through so-called "spike" proteins. Determining the shape of the spike protein in SARS-CoV-2 is the key to discovering how to target the virus directly, said Jason McLellan, lead author of the study and professor at the University of Texas at Austin.
Although the coronavirus uses many different proteins to reproduce and invade cells, the spike protein is the main protein that the virus uses to bind to a receptor – another protein that acts as an entry gate into a human cell. After the spike protein binds to the human cell receptor, the viral membrane fuses with the human cell membrane, allowing the virus's genome to enter the human cell and begin infection. So "if we can prevent the attachment and fusion, we will prevent entry," McLellan told Live Science.
For this reason, it is recommended that everyone wear a mask in public places. The recommendation is imperative, especially in enclosed spaces or where it is difficult to maintain a distance of 2 meters from those around you. This helps slow the spread of the virus from asymptomatic people and from individuals who do not know they have contracted the virus.
In addition to wearing masks, the use of hand sanitizers is also essential for preventing the spread of the SARS-CoV-2 virus in public spaces. Hand sanitizers that contain at least 60% alcohol are recommended by health organizations, including the World Health Organization (WHO), as an effective way to destroy viruses and bacteria on the hands.
When soap and water are not available, hand sanitizers provide a practical and quick solution for cleaning and disinfecting hands. They work by destroying the cell membranes of viruses and bacteria, thereby reducing the risk of their transmission.
It is important to use hand sanitizer correctly. Apply a sufficient amount of gel to the entire surface of your hands and rub them together until they are completely dry. Make sure to cover all areas, including the fingertips and the spaces between them.
In addition, it is important to choose a hand sanitizer with an appropriate alcohol content, as its concentration is essential for its effectiveness. Also, avoid touching your face with un-sanitized hands to prevent possible contamination.
Overall, the correct and frequent use of hand sanitizers, along with other personal hygiene measures and social distancing, can contribute to reducing the risk of transmission of the SARS-CoV-2 virus and other respiratory infections in public spaces.
