CHALLENGES AND PROGRESS IN DEVELOPMENT OF VACCINE FOR COVID-19: A REVIEW
Keywords:Coronavirus, COVID-19, SARS-CoV-2, vaccine development, DNA vaccine, RNA vaccine, non-replication viral vector vaccine, inactivated virus particle vaccine, neutralizing antibodies
The world has experienced several epidemics posing serious threat to global public health, including the 2002 severe acute respiratory syndrome (SARS) epidemic that caused 800 deaths out of about 8 000 cases, the 2009 H1N1 pandemic with 18 500 deaths, the 2012 Middle East respiratory syndrome (MERS) epidemic that caused 800 deaths out of 2 500 cases, the 2014 Ebola outbreak with 28616 cases and 11310 deaths, and the current coronavirus disease (COVID-19) pandemic with more than 2,321,772 deaths out of over 106,404,698 confirmed cases till now.and is affecting 213 countries all over the world. Coronavirus (CoV) disease‑2019 (COVID‑19) is an infectious disease caused by the severe acute respiratory syndrome‑CoV‑2. The disease started in 2019 in Wuhan, China, and has spread globally, resulting in a pandemic. Common symptoms include fever, cough, and shortness of breath. Muscle pain, sputum production, and sore throat are less common symptoms. While the majority of cases result in mild symptoms, some progress to pneumonia and multiorgan failure. The deaths per number of diagnosed cases is estimated at between 1% and 5%, on an average but varies by age and other health conditions. The infection is spread from one person to others via respiratory droplets, often produced during coughing and sneezing. It takes 2–14 days to develop symptoms from the day of exposure. Reverse transcription‑polymerase chain reaction from a nasopharyngeal swab or oropharyngeal swab is the standard method of diagnosis. The infection can also be diagnosed from a combination of symptoms, risk factors, and a chest computed tomography scan showing features of viral pneumonia. Measures recommended to prevent the disease include frequent hand washing, maintaining distance from other people, and not touching one’s face. The use of masks is recommended for those who are suspected to have the virus and to their caregivers, besides the general public. The importance of a collaborative international effort, the ethical implications of vaccine development, the efficacy needed for an immunogenic vaccine, vaccine coverage, the potential limitations and challenges of vaccine development. Although the demand for a vaccine far surpasses the production capacity, it will be beneficial to have a limited number of vaccines available for the more vulnerable population by the end of 2020 and for the rest of the global population by the end of 2021.
Keywords: Coronavirus; COVID-19; SARS-CoV-2; vaccine development, DNA vaccine, RNA vaccine, non-replication viral vector vaccine, inactivated virus particle vaccine, neutralizing antibodies