The novel coronavirus termed SARS-CoV-2 belongs to the family of coronaviruses. It is characterized by a spiky, crown-like appearance (Latin: corona = crown). Biologically, the virus is related to the viruses which cause MERS (MERS-CoV) or SARS (SARS-CoV), both of which can also trigger severe pneumonia. There are also several harmless coronaviruses which cause flu-like illnesses without severe disease. However, the actual “flu” is caused by influenza viruses.
One or more of the following symptoms may appear after an average of 5 or 6 days, but no later than 14 days, after infection:
Other typical symptoms include: sore throat, difficulty breathing, headache, joint pain, loss of appetite, weight loss, nausea, abdominal pain, vomiting, diarrhea, conjunctivitis, rash, swollen lymph nodes, apathy, or insomnia.
SARS-CoV-2 can cause severe disease of many organ systems. The disease caused by the virus is called Coronavirus Disease 2019, or COVID-19 for short.
COVID-19 may affect the following organ systems:
SARS-CoV-2 is highly infectious: if only a small number of people are vaccinated against SARS-CoV-2, the virus can continue to spread. Once a large percentage of people have been vaccinated, a condition called herd immunity develops. This makes it difficult or even impossible for the virus to keep spreading.
Between 60% and 80%
of the entire population must be vaccinated in order to achieve the goal of
However, data from Israel - where over 50% of the population has already been vaccinated - show a major reduction in asymptomatic and symptomatic SARS-CoV-2 infections among people who have been vaccinated compared with those who have not. This data suggest that people who are vaccinated might become infected and/or infect others at lower rates. However, the data available on this question is currently limited and does not yet cover every vaccine.
Hence, it will still be important to follow the safety rules of distancing, hygiene, mask wearing, ventilation, and using the coronavirus smartphone app to keep the risk of infection as low as possible for people who are not vaccinated.
Vaccination provides excellent protection from COVID-19 disease. It is not yet known how long protection lasts after COVID-19 vaccination, which is another reason why it is important for vaccinated people to keep following distancing and hygiene rules.