Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the virus SARS-CoV-2. The first known case was identified in Wuhan, China, in December 2019.[7] The disease quickly spread worldwide, resulting in the COVID-19 pandemic.
The symptoms of COVID‑19 are variable but often include fever,[8] cough, headache,[9] fatigue, breathing difficulties, loss of smell, and loss of taste.[10][11][12] Symptoms may begin one to fourteen days after exposure to the virus. At least a third of people who are infected do not develop noticeable symptoms.[13][14] Of those who develop symptoms noticeable enough to be classified as patients, most (81%) develop mild to moderate symptoms (up to mild pneumonia), while 14% develop severe symptoms (dyspnea, hypoxia, or more than 50% lung involvement on imaging), and 5% develop critical symptoms (respiratory failure, shock, or multiorgan dysfunction).[15] Older people are at a higher risk of developing severe symptoms. Some people continue to experience a range of effects (long COVID) for months or years after infection, and damage to organs has been observed.[16] Multi-year studies are underway to further investigate the long-term effects of the disease.[17]
COVID‑19 transmits when infectious particles are breathed in or come into contact with the eyes, nose, or mouth. The risk is highest when people are in close proximity, but small airborne particles containing the virus can remain suspended in the air and travel over longer distances, particularly indoors. Transmission can also occur when people touch their eyes, nose or mouth after touching surfaces or objects that have been contaminated by the virus. People remain contagious for up to 20 days and can spread the virus even if they do not develop symptoms.[18]
Testing methods for COVID-19 to detect the virus’s nucleic acid include real-time reverse transcription polymerase chain reaction (RT‑PCR),[19][20] transcription-mediated amplification,[19][20][21] and reverse transcription loop-mediated isothermal amplification (RT‑LAMP)[19][20] from a nasopharyngeal swab.[22]
Several COVID-19 vaccines have been approved and distributed in various countries, which have initiated mass vaccination campaigns. Other preventive measures include physical or social distancing, quarantining, ventilation of indoor spaces, use of face masks or coverings in public, covering coughs and sneezes, hand washing, and keeping unwashed hands away from the face. While work is underway to develop drugs that inhibit the virus, the primary treatment is symptomatic. Management involves the treatment of symptoms through supportive care, isolation, and experimental measures.
From Wikipedia, the free encyclopedia
A COVID‑19 vaccine is a vaccine intended to provide acquired immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID‑19).
Prior to the COVID‑19 pandemic, an established body of knowledge existed about the structure and function of coronaviruses causing diseases like severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). This knowledge accelerated the development of various vaccine platforms in early 2020.[1] The initial focus of SARS-CoV-2 vaccines was on preventing symptomatic, often severe, illness.[2] In 2020, the first COVID‑19 vaccines were developed and made available to the public through emergency authorizations[3] and conditional approvals.[4][5] Initially, most COVID‑19 vaccines were two-dose vaccines, with the sole exception being the single-dose Janssen COVID‑19 vaccine.[3] However, immunity from the vaccines has been found to wane over time, requiring people to get booster doses of the vaccine to maintain protection against COVID‑19.[3]
The COVID‑19 vaccines are widely credited for their role in reducing the spread of COVID‑19 and reducing the severity and death caused by COVID‑19.[3][6] According to a June 2022 study, COVID‑19 vaccines prevented an additional 14.4 to 19.8 million deaths in 185 countries and territories from 8 December 2020 to 8 December 2021.[7][8] Many countries implemented phased distribution plans that prioritized those at highest risk of complications, such as the elderly, and those at high risk of exposure and transmission, such as healthcare workers.[9][10]
Common side effects of COVID‑19 vaccines include soreness, redness, rash, inflammation at the injection site, fatigue, headache, myalgia (muscle pain), and arthralgia (joint pain), which resolve without medical treatment within a few days.[11][12] COVID‑19 vaccination is safe for people who are pregnant or are breastfeeding.[13]
As of 1 February 2024, 13.57 billion doses of COVID‑19 vaccines have been administered worldwide, based on official reports from national public health agencies.[14] By December 2020, more than 10 billion vaccine doses had been preordered by countries,[15] with about half of the doses purchased by high-income countries comprising 14% of the world’s population.[16]
Despite the extremely rapid development of effective mRNA and viral vector vaccines, worldwide vaccine equity has not been achieved. The development and use of whole inactivated virus (WIV) and protein-based vaccines have also been recommended, especially for use in developing countries.[17][18]
The 2023 Nobel Prize in Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman for the development of effective mRNA vaccines against COVID-19.[19][20][21]
Design by Smart it link جميع الحقوق محفوظة ( مجمع ارفا الطبي )
