Covid-19 (Corona virus disease 2019)
Covid-19 is a viral infection spread by the coronavirus SARS-CoV-2. There are several different coronaviruses, some causing common colds while variants SARS and MERS can cause more serious infections. SARS-CoV-2 is primarily an airborne infection. It can be transmitted from animal to human, although it is not common. It is called zoonosis and it is believed that this is how the infection first arose. In 2020, the SARS-CoV-2 virus spread after an outbreak in China around the world and caused a pandemic. Like other viruses, SARS-CoV-2 can be altered to produce new strains. Such so-called mutations have so far caused “English”, “South African” and “Brazilian” variants of the virus.
The time from the time you become infected until you show symptoms, so-called incubation period, is usually 2-14 days. Most people fall ill around the fifth day after the time of infection. Common symptoms are fever, cough, fatigue, difficulty breathing, headache, sore throat, nasal congestion, runny nose, muscle and joint pain and nausea or diarrhea. Some people have a reduced sense of taste and smell. Many become mildly ill, but some have severe problems that require hospitalisation and in some cases intensive care. International mortality is calculated on the basis of the data currently available at 0.5-1% and older people are at greater risk of severe infection.
There is currently no cure for Covid-19. For those who are hospitalised, oxygen treatment is often needed. Knowledge about the disease is gradually increasing and it has been noted that many seriously ill people have an increased risk of blood clots. Therefore, it is common for these patients to be treated prophylactically with blood thinners. Cortisone treatment to reduce inflammation also seems to have a positive effect in severe cases.
The disease is covered by the Communicable Diseases Act. Everyone needs help to slow down the spread of infection by following the Swedish Public Health Agency’s recommendations. If you have been infected, you need to isolate yourself for at least seven days, longer if you have continued symptoms. You must have been symptom-free for at least two days before you can return to school or work.
In a short time, several different vaccines against the disease have been developed. Two of the vaccines that have been approved by the EU and are used in Sweden are based on a technology based on mRNA that was initially developed in the 1990s, among other things in the hope of finding a vaccine against the disease Ebola. In these vaccines, it is the vaccinated person himself who produces the foreign substance (antigen) to which the immune system reacts. The efficiency is high in the studies that have been published. The Comirnaty vaccine from Pfizer and BioNTech is given in two doses at six-week intervals between doses (minimum interval 21 days) and Moderna’s vaccine is given in two doses at least four-week intervals between doses.
The EU has also approved Astra Zeneca’s vaccine Vaxzevria, which is currently used by the elderly in Sweden (April 2021). Here, a harmless adenovirus is used as a carrier of genetic information from the coronavirus. The vaccine is given in two doses at 9-12 week intervals.
The EU has also approved a Covid-19 vaccine from Janssen that is given in one dose. Like Vaxzevria, it is a so-called vector vaccine where an adenovirus is used as a carrier.
All vaccines are given intramuscularly. It is not yet known how long the protection lasts after vaccination.