COVID-19

Настоящата информационна кампания има за цел да запознае населението с вируса COVID-19,
начини за предпазване, рискове и мерки, които трябва да предприемат за справяне с епидемията.

Coronaviruses are a large family of viruses which may cause illness in animals or humans.  In humans, several coronaviruses are known to cause respiratory infections ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). The most recently discovered coronavirus causes coronavirus disease COVID-19.

COVID-19 is the infectious disease caused by the most recently discovered coronavirus. This new virus and disease were unknown before the outbreak began in Wuhan, China, in December 2019.

The most common symptoms of COVID-19 are fever, tiredness, and dry cough. Some patients may have aches and pains, nasal congestion, runny nose, sore throat or diarrhea. These symptoms are usually mild and begin gradually. Some people become infected but don’t develop any symptoms and don’t feel unwell. Most people (about 80%) recover from the disease without needing special treatment. Around 1 out of every 6 people who gets COVID-19 becomes seriously ill and develops difficulty breathing. Older people, and those with underlying medical problems like high blood pressure, heart problems or diabetes, are more likely to develop serious illness. People with fever, cough and difficulty breathing should seek medical attention.

People can catch COVID-19 from others who have the virus. The disease can spread from person to person through small droplets from the nose or mouth which are spread when a person with COVID-19 coughs or exhales. These droplets land on objects and surfaces around the person. Other people then catch COVID-19 by touching these objects or surfaces, then touching their eyes, nose or mouth. People can also catch COVID-19 if they breathe in droplets from a person with COVID-19 who coughs out or exhales droplets. This is why it is important to stay more than 1 meter (3 feet) away from a person who is sick.


Can the virus that causes COVID-19 be transmitted through the air?

Studies to date suggest that the virus that causes COVID-19 is mainly transmitted through contact with respiratory droplets rather than through the air.  See previous answer on “How does COVID-19 spread?”


Can CoVID-19 be caught from a person who has no symptoms?

The main way the disease spreads is through respiratory droplets expelled by someone who is coughing. The risk of catching COVID-19 from someone with no symptoms at all is very low. However, many people with COVID-19 experience only mild symptoms. This is particularly true at the early stages of the disease. It is therefore possible to catch COVID-19 from someone who has, for example, just a mild cough and does not feel ill.  WHO is assessing ongoing research on the period of transmission of COVID-19 and will continue to share updated findings.


Can I catch COVID-19 from the feces of someone with the disease?

The risk of catching COVID-19 from the feces of an infected person appears to be low. While initial investigations suggest the virus may be present in feces in some cases, spread through this route is not a main feature of the outbreak. WHO is assessing ongoing research on the ways COVID-19 is spread and will continue to share new findings. Because this is a risk, however, it is another reason to clean hands regularly, after using the bathroom and before eating.

Protection measures for everyone

Stay aware of the latest information on the COVID-19 outbreak, available on the WHO website and through your national and local public health authority. Many countries around the world have seen cases of COVID-19 and several have seen outbreaks. Authorities in China and some other countries have succeeded in slowing or stopping their outbreaks. However, the situation is unpredictable so check regularly for the latest news.

You can reduce your chances of being infected or spreading COVID-19 by taking some simple precautions:

  • Regularly and thoroughly clean your hands with an alcohol-based hand rub or wash them with soap and water.
    Why? Washing your hands with soap and water or using alcohol-based hand rub kills viruses that may be on your hands.
  • Maintain at least 1 metre (3 feet) distance between yourself and anyone who is coughing or sneezing.
    Why? When someone coughs or sneezes they spray small liquid droplets from their nose or mouth which may contain virus. If you are too close, you can breathe in the droplets, including the COVID-19 virus if the person coughing has the disease.
  • Avoid touching eyes, nose and mouth.
    Why? Hands touch many surfaces and can pick up viruses. Once contaminated, hands can transfer the virus to your eyes, nose or mouth. From there, the virus can enter your body and can make you sick.
  • Make sure you, and the people around you, follow good respiratory hygiene. This means covering your mouth and nose with your bent elbow or tissue when you cough or sneeze. Then dispose of the used tissue immediately.
    Why? Droplets spread virus. By following good respiratory hygiene you protect the people around you from viruses such as cold, flu and COVID-19.
  • Stay home if you feel unwell. If you have a fever, cough and difficulty breathing, seek medical attention and call in advance. Follow the directions of your local health authority.
    Why? National and local authorities will have the most up to date information on the situation in your area. Calling in advance will allow your health care provider to quickly direct you to the right health facility. This will also protect you and help prevent spread of viruses and other infections.
  • Keep up to date on the latest COVID-19 hotspots (cities or local areas where COVID-19 is spreading widely). If possible, avoid traveling to places  – especially if you are an older person or have diabetes, heart or lung disease.
    Why? You have a higher chance of catching COVID-19 in one of these areas.

 

Protection measures for persons who are in or have recently visited (past 14 days) areas where COVID-19 is spreading

  • Follow the guidance outlined above (Protection measures for everyone)
  • Self-isolate by staying at home if you begin to feel unwell, even with mild symptoms such as headache, low grade fever (37.3 C or above) and slight runny nose, until you recover. If it is essential for you to have someone bring you supplies or to go out, e.g. to buy food, then wear a mask to avoid infecting other people.
    Why? Avoiding contact with others and visits to medical facilities will allow these facilities to operate more effectively and help protect you and others from possible COVID-19 and other viruses.
  • If you develop fever, cough and difficulty breathing, seek medical advice promptly as this may be due to a respiratory infection or other serious condition. Call in advance and tell your provider of any recent travel or contact with travelers.
    Why? Calling in advance will allow your health care provider to quickly direct you to the right health facility. This will also help to prevent possible spread of COVID-19 and other viruses.

The risk depends on where you  are – and more specifically, whether there is a COVID-19 outbreak unfolding there.

For most people in most locations the risk of catching COVID-19 is still low. However, there are now places around the world (cities or areas) where the disease is spreading. For people living in, or visiting, these areas the risk of catching COVID-19 is higher. Governments and health authorities are taking vigorous action every time a new case of COVID-19 is identified. Be sure to comply with any local restrictions on travel, movement or large gatherings. Cooperating with disease control efforts will reduce your risk of catching or spreading COVID-19.

COVID-19 outbreaks can be contained and transmission stopped, as has been shown in China and some other countries. Unfortunately, new outbreaks can emerge rapidly. It’s important to be aware of the situation where you are or intend to go. WHO publishes daily updates on the COVID-19 situation worldwide.

You can see these at https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports/

Illness due to COVID-19 infection is generally mild, especially for children and young adults. However, it can cause serious illness: about 1 in every 5 people who catch it need hospital care. It is therefore quite normal for people to worry about how the COVID-19 outbreak will affect them and their loved ones.

We can channel our concerns into actions to protect ourselves, our loved ones and our communities. First and foremost among these actions is regular and thorough hand-washing and good respiratory hygiene. Secondly, keep informed and follow the advice of the local health authorities including any restrictions put in place on travel, movement and gatherings.

Learn more about how to protect yourself at https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public

While we are still learning about how COVID-2019 affects people, older persons and persons with pre-existing medical conditions (such as high blood pressure, heart disease, lung disease, cancer or diabetes)  appear to develop serious illness more often than others.

No. Antibiotics do not work against viruses, they only work on bacterial infections. COVID-19 is caused by a virus, so antibiotics do not work. Antibiotics should not be used as a means of prevention or treatment of COVID-19. They should only be used as directed by a physician to treat a bacterial infection.

While some western, traditional or home remedies may provide comfort and alleviate symptoms of COVID-19, there is no evidence that current medicine can prevent or cure the disease. WHO does not recommend self-medication with any medicines, including antibiotics, as a prevention or cure for COVID-19. However, there are several ongoing clinical trials that include both western and traditional medicines. WHO will continue to provide updated information as soon as clinical findings are available.

Yes. To date (14 April 2021), there are a couple of vaccines that prevent treat COVID-19. However, there is still no specific antiviral medicine that treats COVID-19. Those who are affected should receive care to relieve symptoms. People with serious illness should be hospitalized. Most patients recover thanks to supportive care.

The most effective ways to protect yourself and others against COVID-19 are to frequently clean your hands, cover your cough with the bend of elbow or tissue, and maintain a distance of at least 1 meter (3 feet) from people who are coughing or sneezing. (See Basic protective measures against the new coronavirus).

No. The virus that causes COVID-19 and the one that caused the outbreak of Severe Acute Respiratory Syndrome (SARS) in 2003 are related to each other genetically, but the diseases they cause are quite different.

SARS was more deadly but much less infectious than COVID-19. There have been no outbreaks of SARS anywhere in the world since 2003.

The Bulgarian Ministry of Health tells us basic rules in wearing masks and when they are compulsory in the territory of the Republic of Bulgaria.

We suggest that you should wear a mask when it is advised by the Ministry of Health and if you are ill with COVID-19 symptoms (especially coughing) or looking after someone who may have COVID-19. Disposable face mask can only be used once. If you are not ill or looking after someone who is ill then you are wasting a mask. There is a world-wide shortage of masks, so WHO urges people to use masks wisely.

WHO advises rational use of medical masks to avoid unnecessary wastage of precious resources and mis-use of masks  (see Advice on the use of masks).

The most effective ways to protect yourself and others against COVID-19 are to frequently clean your hands, cover your cough with the bend of elbow or tissue and maintain a distance of at least 1 meter (3 feet) from people who are coughing or sneezing. See basic protective measures against the new coronavirus for more information.

  1. Remember, a mask should only be used by health workers, care takers, and individuals with respiratory symptoms, such as fever and cough.
  2. Before touching the mask, clean hands with an alcohol-based hand rub or soap and water
  3. Take the mask and inspect it for tears or holes.
  4. Orient which side is the top side (where the metal strip is).
  5. Ensure the proper side of the mask faces outwards (the coloured side).
  6. Place the mask to your face. Pinch the metal strip or stiff edge of the mask so it moulds to the shape of your nose.
  7. Pull down the mask’s bottom so it covers your mouth and your chin.
  8. After use, take off the mask; remove the elastic loops from behind the ears while keeping the mask away from your face and clothes, to avoid touching potentially contaminated surfaces of the mask.
  9. Discard the mask in a closed bin immediately after use.
  10. Perform hand hygiene after touching or discarding the mask – Use alcohol-based hand rub or, if visibly soiled, wash your hands with soap and water.

The “incubation period” means the time between catching the virus and beginning to have symptoms of the disease. Most estimates of the incubation period for COVID-19 range from 1-14 days, most commonly around five days. These estimates will be updated as more data become available.

Coronaviruses are a large family of viruses that are common in animals. Occasionally, people get infected with these viruses which may then spread to other people. For example, SARS-CoV was associated with civet cats and MERS-CoV is transmitted by dromedary camels. Possible animal sources of COVID-19 have not yet been confirmed.

To protect yourself, such as when visiting live animal markets, avoid direct contact with animals and surfaces in contact with animals. Ensure good food safety practices at all times. Handle raw meat, milk or animal organs with care to avoid contamination of uncooked foods and avoid consuming raw or undercooked animal products.

While there has been one instance of a dog being infected in Hong Kong, to date, there is no evidence that a dog, cat or any pet can transmit COVID-19. COVID-19 is mainly spread through droplets produced when an infected person coughs, sneezes, or speaks. To protect yourself, clean your hands frequently and thoroughly.

WHO continues to monitor the latest research on this and other COVID-19 topics and will update as new findings are available.

It is not certain how long the virus that causes COVID-19 survives on surfaces, but it seems to behave like other coronaviruses. Studies suggest that coronaviruses (including preliminary information on the COVID-19 virus) may persist on surfaces for a few hours or up to several days. This may vary under different conditions (e.g. type of surface, temperature or humidity of the environment).

If you think a surface may be infected, clean it with simple disinfectant to kill the virus and protect yourself and others. Clean your hands with an alcohol-based hand rub or wash them with soap and water. Avoid touching your eyes, mouth, or nose.

Yes. The likelihood of an infected person contaminating commercial goods is low and the risk of catching the virus that causes COVID-19 from a package that has been moved, travelled, and exposed to different conditions and temperature is also low.

The following measures ARE NOT effective against COVID-2019 and can be harmful:

  • Smoking
  • Wearing multiple masks
  • Taking antibiotics (See question 10 “Are there any medicines of therapies that can prevent or cure COVID-19?“)

In any case, if you have fever, cough and difficulty breathing seek medical care early to reduce the risk of developing a more severe infection and be sure to share your recent travel history with your health care provider.

Scientists around the world are developing many potential vaccines for COVID-19. These vaccines are all designed to teach the body’s immune system to safely recognize and block the virus that causes COVID-19. Several different types of potential vaccines for COVID-19 are in development, including:

  • Inactivated or weakened virus vaccines, which use a form of the virus that has been inactivated or weakened so it doesn’t cause disease, but still generates an immune response.
  • Protein-based vaccines, which use harmless fragments of proteins or protein shells that mimic the COVID-19 virus to safely generate an immune response.
  • Viral vector vaccines, which use a safe virus that cannot cause disease but serves as a platform to produce coronavirus proteins to generate an immune response.
  • RNA and DNA vaccines, a cutting-edge approach that uses genetically engineered RNA or DNA to generate a protein that itself safely prompts an immune response.

For more information about all COVID-19 vaccines in development, see this WHO publication, which is being updated regularly. 

The COVID-19 vaccines produce protection against the disease, as a result of developing an immune response to the SARS-Cov-2 virus.  Developing immunity through vaccination means there is a reduced risk of developing the  illness and its consequences. This immunity helps you fight the virus if exposed. Getting vaccinated may also protect people around you, because if you are protected from getting infected and from disease, you are less likely to infect someone else. This is particularly important to protect people at increased risk for severe illness from COVID-19, such as healthcare providers, older or elderly adults, and people with other medical conditions.

https://www.who.int/news-room/q-a-detail/coronavirus-disease-(covid-19)-vaccines-safety

There are strict protections in place to help ensure the safety of all COVID-19 vaccines. Before receiving validation from WHO and national regulatory agencies, COVID-19 vaccines must undergo rigorous testing in clinical trials to prove that they meet internationally agreed benchmarks for safety and effectiveness.

Unprecedented scientific collaborations have allowed COVID-19 vaccine research, development, and authorizations to be completed in record time – to meet the urgent need for COVID-19 vaccines while maintaining high safety standards. As with all vaccines, WHO and regulatory authorities will continuously monitor the use of COVID-19 vaccines to confirm that they remain safe for all who receive them.

Like any vaccine, COVID-19 vaccines can cause mild side effects, such as a low-grade fever or pain or redness at the injection site. Most reactions to vaccines are mild and go away within a few days on their own. More serious or long-lasting side effects to vaccines are possible but extremely rare. Vaccines are continually monitored to detect rare adverse events. 

Reported side effects to COVID-19 vaccines have mostly been mild to moderate and short-lasting. They include fever, fatigue, headache, muscle pain, chills, diarrhea, and pain at the injection site. The chances of any of these side effects following vaccination differ according to the specific COVID-19 vaccine.

While several COVID-19 vaccines appear to have high levels of efficacy, no vaccine is 100% protective. As a result, there may be a small percentage of people who do not develop protection as expected after COVID-19 vaccination.

In addition to a vaccine’s specific characteristics, several factors such as a person’s age, their underlying health conditions or previous exposure to COVID-19 may have an impact on a vaccine’s effectiveness. We also do not yet know how long immunity from different COVID-19 vaccines will last. That is one reason why, even as COVID-19 vaccines start to be rolled out, we must continue using all public health measures that work, such as physical distancing, masks, and handwashing.

Medical professionals can best advise individuals on whether or not they should receive a COVID-19 vaccine. However, based on available evidence, people with the following health conditions should generally be excluded from COVID-19 vaccination in order to avoid possible adverse effects:

  • If you have a history of severe allergic reactions to any ingredients of the COVID-19 vaccine
  • If you are currently sick or experiencing symptoms of COVID-19, though you can get vaccinated once your primary symptoms have resolved.

Further research is needed to determine the safety and efficacy of different COVID-19 vaccines in certain population groups. In addition to the general recommendations above, each vaccine may have specific considerations for specific populations and health conditions.

Based on what we know about these vaccines, we don’t have any specific reason to believe there will be risks that would outweigh the benefits of vaccination for pregnant women. While pregnancy puts women at higher risk of severe COVID-19, very little data are available to assess vaccine safety in pregnancy.  

For this reason, those pregnant women at high risk of exposure to SARS-CoV-2 (e.g., health workers) or who have comorbidities which add to their risk of severe disease may be vaccinated in consultation with their health care provider.

It is not yet clear whether COVID-19 vaccines can be excreted through breastfeeding. To determine the best course of action, the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for immunization against COVID-19. WHO does not recommend discontinuing breastfeeding after vaccination.

The COVID-19 mRNA vaccine technology has been rigorously assessed for safety, and clinical trials have shown that mRNA vaccines provide a long-lasting immune response. mRNA vaccine technology has been studied for several decades, including in the contexts of Zika, rabies, and influenza vaccines. mRNA vaccines are not live virus vaccines and do not interfere with human DNA.

When a virus replicates or makes copies of itself, it sometimes changes a little bit. These changes are called “mutations.” A virus with one or several new mutations is referred to as a “variant” of the original virus. 

The more viruses circulate, the more they may change. These changes can occasionally result in a virus variant that is better adapted to its environment compared to the original virus. This process of changing and selection of successful variants is called “virus evolution.”

Some mutations can lead to changes in a virus’s characteristics, such as altered transmission (for example, it may spread more easily) or severity (for example, it may cause more severe disease).

Some viruses change quickly and others more slowly. SARS-CoV-2, the virus which causes COVID-19, tends to change more slowly than others such as HIV or influenza viruses. This could in part be explained by the virus’s internal “proofreading mechanism” which can correct “mistakes” when it makes copies of itself. Scientists continue to study this mechanism to better understand how it works.

It is normal for viruses to change, but it is still something scientists follow closely because there can be important implications. All viruses, including SARS-CoV-2, the virus that causes COVID-19, change over time. So far hundreds of variations of this virus have been identified worldwide. WHO and partners have been following them closely since January 2020.

Most changes have little to no impact on the virus’ properties. However, depending on where the changes are located in the virus’s genetic material, they may affect the virus’s properties, such as transmission (for example, it may spread more easily) or severity (for example, it may cause more severe disease).

WHO and its international network of experts are monitoring changes to the virus so that if significant mutations are identified, WHO can report any modifications to interventions needed by countries and individuals to prevent the spread of that variant.  The current strategies and measures recommended by WHO continue to work against virus variants identified since the start of the pandemic.

The best way to limit and suppress the transmission of COVID-19 is for people to continue taking the necessary precautions to keep themselves and others safe.

The most commonly used vaccines have been around for decades, with millions of people receiving them safely every year. As with all medicines, every vaccine must go through extensive and rigorous testing to ensure it is safe before it can be introduced in a country.

An experimental vaccine is first tested in animals to evaluate its safety and potential to prevent disease. It is then tested in human clinical trials, in three phases:

  • In phase I, the vaccine is given to a small number of volunteers to assess its safety, confirm it generates an immune response, and determine the right dosage.
  • In phase II, the vaccine is usually given to hundreds of volunteers, who are closely monitored for any side effects, to further assess its ability to generate an immune response. In this phase, data are also collected whenever possible on disease outcomes, but usually not in large enough numbers to have a clear picture of the effect of the vaccine on disease. Participants in this phase have the same characteristics (such as age and sex) as the people for whom the vaccine is intended. In this phase, some volunteers receive the vaccine and others do not, which allows comparisons to be made and conclusions drawn about the vaccine.
  • In phase III, the vaccine is given to thousands of volunteers – some of whom receive the investigational vaccine, and some of whom do not, just like in phase II trials. Data from both groups is carefully compared to see if the vaccine is safe and effective against the disease it is designed to protect against.

Once the results of clinical trials are available, a series of steps is required, including reviews of efficacy, safety, and manufacturing for regulatory and public health policy approvals, before a vaccine may be introduced into a national immunization programme.

Following the introduction of a vaccine, close monitoring continues to detect any unexpected adverse side effects and further assess effectiveness in the routine use setting among even larger numbers of people to continue assessing how best to use the vaccine for the greatest protective impact. More information about vaccine development and safety is available here.