everything about COVID 19
Like many other respiratory viruses, coronaviruses spread quickly through droplets that you project out of your mouth or nose when you breathe, cough, sneeze, or speak. The word corona means crown and refers to the appearance that coronaviruses get from the spike proteins sticking out of them. These spike proteins are important to the biology of this virus. The spike protein is the part of the virus that attaches to a human cell to infect it, allowing it to replicate inside of the cell and spread to other cells. Some antibodies can protect you from SARS-CoV-2 by targeting these spike proteins. Because of the importance of this specific part of the virus, scientists who sequence the virus for research constantly monitor mutations causing changes to the spike protein through a process called genomic surveillance.
As genetic changes to the virus happen over time, the SARS-CoV-2 virus begins to form genetic lineages. Just as a family has a family tree, the SARS-CoV-2 virus can be similarly mapped out. Sometimes branches of that tree have different attributes that change how fast the virus spreads, or the severity of illness it causes, or the effectiveness of treatments against it. Scientists call the viruses with these changes “variants”. They are still SARS-CoV-2, but may act differently.
Pcr tests for visitors and testing centers for visitors: https://www.koronavirus.hr/testing-centers-in-croatia/764