Coronavirus disease 2019 (COVID-19) is an acute respiratory illness with a wide range of manifestations: from a simple cold to mild, moderate, or severe pneumonia, sepsis, septic shock, or death. This disease started in a live animal market in Wuhan City, Hubei Province, China, in December of 2019. Its aetiological name is severe acute respiratory syndrome coronavirus 2, and its origin has not yet been determined, but it is likely from wildlife and now has mutated into different coronavirus strains. Phylogenetic studies suggest but do not confirm that the virus may have originated in bats. So far in the 21st century, this is the third human disease caused by a highly pathogenic coronavirus. The first two were SARS and MERS.
Symptoms of COVID-19
People who suffer from COVID-19 disease have at least one of the following signs and symptoms:
It is accompanied by at least one of the following: sore or burning throat, red eyes, muscle or joint pain (malaise). The most serious symptoms are difficulty breathing or shortness of oxygen intake, which have to be treated immediately. It is a dangerous disease mainly for older adults and has affected more than 100 million people worldwide, killing more than 2 million.
Different Coronavirus Strains
Since the start of the covid-19 pandemic, it has been common to hear comments about the fear that SARS-CoV-2 could mutate into a more severe form. To many people, the virus was envisioned as an entity capable of making decisions to ensure that it remained with us. The reality is, viruses do not make the decisions. When they infect and attack a cell, they start to multiply almost automatically, and this includes copying their genetic information.
During the copying process, errors often occur, which, although they often have no effect, sometimes lead to changes in some of the amino acids that make up the virus’ proteins.
Thus, the structure of these macromolecules and the entire structure of the virus can be altered, and with it, the characteristics of the virus itself. Three new coronavirus strains (SARS-CoV-2) that cause coronavirus disease 2019 (COVID-19) are currently causing concern. These coronavirus strains have the power of transmitting the disease among people more easily and rapidly, causing more infections throughout the globe. The three coronavirus strains have already been identified in the United States as well as in many other countries.
British Strain (B.1.1.7): The British strain (B.1.1.7) was first detected in December in two people in the south-east of the UK but has already spread to 60 countries. The Ministry of Health explains that this strain, called VOC B.1.1.7, “belongs to the B.1.1.7 lineage and has 28 changes in its complete genome” compared to the original virus. A report found that this strain could be up to 74 percent more contagious in December, although subsequent studies have lowered this to 24 to 57 percent and even 19 to 53 percent. The opposite is true for lethality. Initially thought not to increase deaths, it may lead to an increase in the severity of the infection with an increased risk of death. The lethality of OCV B.1.1.7 compared to other coronavirus strains would be between 1.07 and 2.71 times greater according to studies, all adjusted for a date, location, age, and other variables.
South African strain (B.1.351): South Africa announced they had found a new strain called B.1.351, also due to the presence of the N501Y mutation. This same mutation is present in the B.1.1.7 strain, although phylogenetic analysis indicates that they are different coronavirus strains. This strain has displaced the other strains circulating in South Africa since November, indicating that it may have a higher transmission capacity without evidence of increased virulence.
Brazilian Strain (P.1): The new strain belongs to the B.184.108.40.206 or P.1. lineage and has three biologically significant mutations in the spicule protein, including the N501Y mutation (like the British and South African strains) and the E484K mutation (like the South African strain and previously described as an escape mutation to neutralization by monoclonal and polyclonal antibodies). Brazil has also reported the presence of this new strain in several sequences (13 out of 31) from the Manaus region (in Amazonia) collected in the second half of December 2020, so the direction of transmission is assumed to have been from Brazil to Japan. The effect of this combination on transmissibility and antibody neutralization capacity is currently being studied.
So far, the developers of the most advanced vaccines, such as Moderna and Pfizer/BionTech, and Sputnik V, Chinese and Cuban pharmaceuticals, have assured that there is no reason why the vaccine compounds should not be effective in combating the disease. However, scientists add that they remain vigilant in this regard, as the relatively recent emergence of these coronavirus strains means that their behavior has not been sufficiently studied to affirm vaccines’ efficacy against them categorically.