COVID-19

**Coronavirus disease 2019** or **COVID-19** is an infectious disease caused by the coronavirus SARS-CoV-2. This virus is kind of like the older SARS virus.

The virus SARS-CoV-2 is the cause of the COVID-19 pandemic. People who catch COVID-19 may get a fever, dry cough, fatigue, (extreme tiredness) loss of taste or smell, or trouble breathing. Sore throat, runny nose, and cough are also common. COVID-19 has killed more than seven million people around the world. 

5 to 50 percent of people who get the disease, COVID-19, will get Long COVID.

The COVID-19 virus, SARS-CoV-2, goes from one person to another by droplets. It can also go from one person to another by small airborne particles. Droplets and particles are made when a person breathes, sneezes, or talks.

## Symptoms
A person with COVID-19 can have these signs and symptoms:
*Fever
*Cough
*Tiredness
*Muscle pain
*Loss of appetite
*Dyspnoea (trouble breathing)

The United States Center for Disease Control says COVID-19 makes people feel sick in a lot of ways. The biggest bad changes can be felt in the lungs. People cough and have problems breathing. They often have a fever, feel cold, have a headache, pain in their muscles, or have problems tasting or smelling things.

An April 2020 scientific study by the American Gastroenterological Association said that COVID-19 can made sick people throw up or have diarrhea. Both are not seen often. They said about 7.7% of COVID-19 patients threw up, about 7.8% had diarrhea, and about 3.6% had pain in their stomach.

## Name
On February 2020, the World Health Organization said they had chosen a name for the disease caused by SARS-CoV-2. They changed it to COVID-19 from the earlier name "2019-nCoV." "Co" is for "corona," "Vi" for "virus," and "D" for "disease," and "19" for the year 2019 . They said they did not want the name to have any person, place, or animal in it, like "Wuhan," because then people might think bad things on said place, person, or animal. They also wanted the name to be easy to say.

## How the virus causes disease 
Scientists looked at the lungs from people who died of COVID-19.  They looked at side-by-side to lungs from people who died of influenza A and to lungs from people who died but did not from any problem with their lungs.  They saw the cells that made up the sides of the blood vessels in the lungs were more badly changed in the lungs from COVID-19 patients, and that there was more blood clotting. The most important difference the scientists saw was that the lungs had begun to grow new blood vessels. Smoking marijuana and tobacco and vaping, while sick with COVID-19, can be very bad.

### Other organs
Scientists from Columbia University say the virus damages the inside of the blood vessels, which causes blood clotting.  The blood clots travel through the body and can cause problems to the heart, kidneys and other parts of the human body. The virus can also cause problems to organs by itself. In 2020, New York City hospitals said 50% of COVID-19 patients had kidney failure in some way. The scientists said that the kidneys have many ACE2 protein receptors, the same receptor that SARS-CoV-2 uses to infect cells.

## COVID-19 and pollution
Scientists saw that more people died from COVID-19 in places with large amounts of air pollution.  One team of scientists from Martin Luther University Halle-Wittenberg looked at air pollution information from satellites and statistics on COVID-19 deaths in Italy, France, Germany, and Spain and saw that places with large amounts of nitrogen dioxide pollution had more people die from COVID-19. Nitrogen dioxide can damage the lungs.

## Transmission and prevention 
There are many ways to stop the spread of COVID-19. Some say washing hands helps, but this does not stop a lot of people from getting COVID-19.

People should stay away from places with lots of people if they can, because being close to big groups of people can easily spread the virus. In fact, many health organizations say that people should stay at least two meters or six feet from another person.

Many people wear face masks in public to stop getting the virus, and it is liked by countries such as China, Hong Kong and Thailand. Most face masks work best to stop you giving the virus to other people. When people with the virus wear masks they give it to less people. One study published in *Cell* showed that wearing a mask pulled down to cover the mouth but not the nose was not good. People usually breathe through their noses and not their mouths. Scientists saw that nose cells were more likely to have the virus in them than throat cells. Since breathing out through the nose was more likely to spread the virus than breathing out through the mouth, people should wear masks that cover their noses.

N95s, and other respirators are said to be better than surgical masks and cloth face masks when stopping the virus that causes COVID-19.

One scientific paper in China saw the virus in semen from men with COVID-19, but other scientific papers saw no virus there.
## Tests and testing
One way people test for COVID-19 is through polymerase chain reaction (PCR) technology.

Scientists and governments like people to test for COVID-19.  Some people may have SARS-CoV-2 in their bodies but not feel sick right away.  These people can give the virus to others.

There are two types of tests.  Viral tests show if a person has the virus right now.  Antibody tests show whether the person has had the virus, but no longer feels sick.

## Medicines 
### Vaccines
:*See also:* BCG vaccine
In April 2020, the group Coalition for Epidemic Preparedness Innovations (CEPI) said that scientists were looking at 115 compounds that could be a vaccine. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, says it takes 18 months to test a vaccine to make sure it works and is safe.

In April 2020, scientists from the University of Pittsburgh said they had made a vaccine, called PittCoVacc, and tested it in mice.

Another team of scientists led by Dr. Josef Penninger of the University of British Columbia invented a medicine called  APN01. They tested APN01 in engineered human tissue. This is human cells put together to act like part of the body, but it is not a whole animal or person. They added a protein called "human recombinant soluble angiotensin converting  enzyme 2" (hrsACE2) and saw that it stopped the virus from taking over cells.  They named their hrsACE2 APN01.

, and more so during this pandemic. If everyone washed their hands, they can help give doctors and other people who work in health and medicine more time to help people.]]

In late April 2020, a team from Oxford University said that they had developed a COVID-19 vaccine.  The United States National Institutes of Health tested it in rhesus monkeys, and it worked.  Because they had already been working on a vaccine against a different coronavirus, they had a head start working on one for SARS-CoV-2. They would try to test their vaccine on 6000 people by the end of May 2020, and that their vaccine could be ready for people to use in September 2020.

In November 2020, two companies, Pfizer and Moderna both said their vaccines had completed some testing.  Both were over 90% effective.  Both companies asked the United States Food and Drug Administration for permission to start giving the vaccine to people.  Both the Pfizer and Moderna vaccines are messenger RNA vaccines they teach the body to recognize the virus.  They say mRNA vaccines take less time to develop and make than protein or whole-virus vaccines.

### Interferon beta
A study from a British company called Synairgen showed that some patients with mild COVID-19 who took interferon beta were less likely to develop severe COVID-19, and they got better faster.  The doctors gave the patients interferon beta by letting them breathe in a spray. The study was performed on 101 patients,  In March, the United States Food and Drug Administration allowed doctors to give hydroxychloroquine and another drug called chloroquine to COVID-19 patients, but in June, they told doctors to stop.  By then, more studies had shown that the drugs did not help much and could harm the patients' hearts.

### Remdesivir
Some scientists also think the drug remdesivir, which was invented as a medicine for Ebola, could work against SARS-CoV-2.  Remdesivir works against other viruses and it has already been tested in humans, so the doctors already knew it would not hurt the patients even if it did not make them better.  Because scientists already knew remdesivir was safe, they were able to start testing it in humans right away. On July 3, the European Commission approved remdesivir for use in the very sickest COVID-19 patients.

### Antibodies
Some scientists gave SARS and MERS to llamas so the llamas' immune systems would make antibodies, or natural medicines, against those viruses, and they found a few antibodies that worked.  In a May 2020 study, the scientists said this could work with SARS-CoV-2 too.

### Nirmatrelvir/ritonavir 
## Prevention and treatment 
Masks can be used to stop others from getting sick from COVID-19. The effectiveness of the mask depends on what type of mask it is. While masks like a surgical masks are not effective, others like a N95 are.

Vaccines are said to be good for lessen being very sick with COVID-19. This can stop people from dying. Getting a vaccine again can make being less sick more likely. But as SARS-CoV-2 the virus that causes COVID-19, changes, getting sick becomes more likely. This was first seen in the Delta type, or variant, of SARS-CoV-2. The chances the vaccine worked went down from 91 percent to 66 percent. Vaccine makers have told the public they are able to change the vaccine to keep up with the changes. Government groups like the FDA have the biggest say what type of SARS-CoV-2 the vaccine makers should make their vaccine for. For 2024-2025, the type of SARS-CoV-2 the FDA says vaccine makers should make their vaccine for is called KP.2. KP.2 is a lineage of JN.1.

## Notes 
## References 
## More reading 
* 
## Related pages 
* Long COVID
** COVID-19 effects on brain-related health
* Abenomask (One of the Japanese governmental response against the outbreak)
* Pneumonia and Avian flu (influenza)
* COVID-19 pandemic in mainland China
* COVID-19 in Canada
* COVID-19 pandemic in Japan
* Olfactory (smells)

## Other websites 
* WHO site for COVID-19
* CDC site for COVID-19
* WHO questions on COVID-19