According to the world covid tracker of Johns Hopkins University, SARS-CoV-2 has killed more than 3.7 million people, the number of infected has exceeded 174 million. And if all the particles of the virus circulating on the planet were gathered in one place, how much would they weigh? Israeli scientists have tried to answer this question.
In their study, scientists from the Weizmann Institute calculated the mass of coronaviruses that can be found in one infected person. To do this, they used data from counting the number of viruses in the tissues and various organs of infected rhesus monkeys. Based on these numbers, they calculated how much of the virus could be in human tissue. Previous calculations showed that each SARS-CoV-2 virus weighs 1 femtogram. Scientists estimate that each infected person at the peak of virus activity is a carrier of 10 to 100 billion particles of the pathogen, depending on the viral load. Based on the number of people who become infected worldwide – this is from 1 to 10 million cases at any given time – the authors of the study concluded that the total mass of all viral particles ranges from 100 grams to 10 kilograms. That is, it is heavier than one apple and lighter than a two-year-old child.
Scientists also calculated how many mutations can occur during infection of one patient and the entire population as a whole. To do this, they used previous estimates of the number of mutations of one nucleotide of other coronaviruses. They multiplied it by the number of nucleotides in the SARS-CoV-2 genome and took into account how many times the virus multiplies in the body.
Experts have found that during the infection of one person, the virus accumulates from 0.1 to 1 full-fledged mutation throughout the genome. Given that the average time it takes for one infected patient to infect another person with coronavirus is 4-5 days, one virus can collect up to three mutations per month, which is generally consistent with the established rate of evolution of SARS-CoV-2 …
The study authors noted that these calculations provide more insight into what happens in the body during infection, how many cells are infected, and how quickly the pathogen develops.