In a few months, the Covid-19 coronavirus has spread all around the world, sending billions of people into lockdown, as health services struggle to cope. Since first being recorded late last year in China, the Covid-19 coronavirus has spread around the world, and been declared a pandemic by the World Health Organization. By early spring, Europe had become the worst-affected region, with Italy and Spain particularly hard hit. However, differences in testing mean that the number of cases may be understated for some countries. The number of deaths is sadly a more dependable indicator. Looked at by this measure we again see that the disease is hitting Italy and Spain with particular cruelty. But the trajectory in many countries is the same; the UK and US are a couple of weeks behind Italy in the progress of the epidemic. Meanwhile in Asia, where the disease began, the spread continues, although in China it seems for now to have passed its peak. By the day the total number of reported COVID 19 cases in India stands at 1,024.In Europe most countries have closed schools, and many are in lockdown. Finally, a reminder that most people who contract the disease recover; many may never notice they had it at all.
Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus. Those peoples who get infected with the COVID-19 virus mostly experience mild to moderate respiratory illness and recover without requiring special treatment. Older people and those with underlying medical history like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness. The best way to prevent and slow down transmission is by well informed about the COVID-19 virus, the disease, it causes and how it spreads. Protect yourself and others from infection by washing your hands or using an alcohol based rub frequently and not touching your face. The COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes, so it's important that you also practice respiratory etiquette (for example, by coughing into a flexed elbow).At this time, there are no specific vaccines or treatments for COVID-19. However, there are many ongoing clinical trials evaluating potential treatments. WHO and other medical research centers of developed countries will continue to provide updated information as soon as clinical findings become available.
In the year 2002 world was facing a similar type of virus known as SARS (Severe Acute Respiratory Syndrome). In the present scenario SARS and Corona virus can be called as dizygotic twins. SARS coronavirus (SARS-CoV) - virus identified in 2003. SARS-CoV is thought to be an animal virus from an as-yet-uncertain animal reservoir, perhaps bats, that spread to other animals (civet cats) and first infected humans in the Guangdong province of southern China in 2002.An epidemic of SARS affected 26 countries and resulted in more than 8000 cases in 2003. Since then, a small number of cases have occurred as a result of laboratory accidents or, possibly, through animal-to-human transmission (Guangdong, China). Transmission of SARS-CoV is primarily from person to person. It appears to have occurred mainly during the second week of illness, which corresponds to the peak of virus excretion in respiratory secretions and stool, and when cases with severe disease start to deteriorate clinically. Most cases of human-to-human transmission occurred in the health care setting, in the absence of adequate infection control precautions. Implementation of appropriate infection control practices brought the global outbreak to an end. Symptoms are influenza-like and include fever, malaise, myalgia, headache, diarrhea, and shivering (rigors). No individual symptom or cluster of symptoms has proved to be specific for a diagnosis of SARS. Although fever is the most frequently reported symptom, it is sometimes absent on initial measurement, especially in elderly and immune suppressed patients. Cough (initially dry), shortness of breath, and diarrhea are present in the first and/or second week of illness. Severe cases often evolve rapidly, progressing to respiratory distress and requiring intensive care. Currently, no areas of the world are reporting transmission of SARS. Since the end of the global epidemic in July 2003, SARS has reappeared four times - three times from laboratory accidents (Singapore and Chinese Taipei), and once in southern China where the source of infection remains undetermined although there is circumstantial evidence of animal-to-human transmission. Should SARS re-emerge in epidemic form, WHO will provide guidance on the risk of travel to affected areas. Travelers should stay informed about current travel recommendations. However, even during the height of the 2003 epidemic, the overall risk of SARS-CoV transmission to travelers was low.
Severe acute respiratory syndrome (SARS) is a newly emerged infectious disease caused by SARS-associated corona virus (SARS-CoV). It originated in the Guangdong province of China in late 2002, spread rapidly around the world along international air-travel routes, and resulted in 8,450 cases and 810 deaths in 33 countries and areas on 5 continents. The global outbreak of SARS seriously threatened public health and socioeconomic stability worldwide. Although this outbreak was eventually brought under control in 2003, several isolated outbreaks of SARS subsequently occurred because of accidental releases of the SARS-CoV isolates from laboratories in Taiwan, Singapore, and mainland China. In late 2003 and early 2004, new infections in persons who had contact with animals infected with SARS-CoV strains significantly different from those predominating in the 2002-2003 outbreak were reported in Guangdong, China. These events indicate that a SARS epidemic may recur at any time in the future, either by the virus escaping from laboratory samples or by SARS-CoV isolates evolving from SARS-CoV-like virus in animal hosts.
An ideal SARS and COVID 19 vaccine should 1) elicit highly potent neutralizing antibody responses against a broad spectrum of viral strains; 2) induce protection against infection and transmission; and 3) be safe by not inducing any infection-enhancing antibodies or harmful immune or inflammatory responses. Currently, an inactivated SARS-CoV vaccine is in clinical trials in China. Safety is the major concern for this type of vaccine. The S protein is the major inducer of neutralizing antibodies. Recombinant vector-based vaccines expressing full-length S protein of the late SARS-CoV are under development. These vaccines can induce potent neutralizing and protective responses in immunized animals but may induce antibodies that enhance infection by early human SARS-CoV and animal SARS-CoV-like viruses. Recent studies have demonstrated that recombinant RBD consists of multiple conformational neutralizing epitopes that induce highly potent neutralizing antibodies against SARS-CoV . Unlike full-length S protein, RBD does not contain immune dominant sites that induce non neutralizing antibodies. RBD sequences are relatively conserved. Thus, recombinant RBD or vectors encoding RBD may be used as safe and efficacious vaccines for preventing infection by SARS-CoV with distinct genotypes. |
