Abstract

Background: RNA viruses evolve very fast, with a mutation rate of 103 to 105 base substitution per nucleotides per copy. The mutation is a survival strategy for the viruses, which leads them to survive in the new host. Fitness is defined as the replication capacity of the virus in an experimental setup. Generally, the large population passage of the virus leads to fitness gain, but the world data of the coronavirus infection and death shows the flattened curve with time. It is contradictory to the principle of fitness gain due to large population passage. The coronavirus is losing its potency but remains infectious as it is passaging into millions that leads to a decline in the death of COVID patients and high recovery rates. Fitness loss of coronaviruses attributed to a high level of mutation in the RNA genome as well as host immune response. The current outbreak of SARS CoV-2 is surfaced in December 2019 in Hubei province of China and considered as bats/pangolin origin, spreading 235 countries of the world, infecting nearly 31,664,104 people, and claimed nearly 972,221 lives as of September 24, 2020 (Death rate approximately 3%). This coronavirus has passaged into 31,664,104 people from the beginning of this pandemic until September 24, 2020. Now the virus is losing potency rather than being monotonous and continuous in producing virusrelated complications. The population is still getting infected at the same rate, but the severity of the disease is reduced due to the potency of the virus diminished due to the passage effect as well as fitness loss of the virus due to high mutation rates. The death rate is reduced to 3% as compared to 6% in June 2020, when this paper was first submitted.

Objective: The purpose of the study is to prove the fact that the coronavirus loses its potency with time but, they remain infective. It becomes more infectious due to mutation of the gene but loses the capacity to kill the host.

Methods: Since the WHO announces the COVID-19 outbreak is an emergency of international concern, every country in the world is taking many measures to mitigate the viral load to their population. Simultaneously, the WHO, CDC USA, CDC Europe, and much other organization is updating the COVID cases and death online daily as reported by the respective country. With the help of the COVID-19 outbreak data published by the European CDC and ourworldindata.org, we correlate the total cases of coronavirus and total death in the top ten affected countries in the world. We also link the trends of total cases vs. total death and total new cases vs. total new death related to COVID-19 in Germany, Spain, the United Kingdom, Italy, and New Zealand from January 30, 2020, until September 24, 2020. The reason to select these countries for the study is that these countries updating the COVID cases and deaths regularly and said to achieve the peak of COVID related infections and recovering from the pandemic.

Results: We have tried to correlate the high mutation rate of the virus that leads to losing its potency to severe infection and death in the human. Viral extinction through high mutation could be considered as the new anti-viral strategies.

Conclusion: Coronavirus is losing its potency to causing death to the human. The new infection is still being reported from every corner of the world, but the death rate is significantly decreasing.

Keywords: SARS Coronavirus-2, COVID-19, mutation, fitness loss, flattened curve, coronaviridae family.

Graphical Abstract