Remember asking yourself just how much corona would weigh? Well, ask no more as this group of researchers has found an answer for you. They have successfully calculated just how much all of the COVID-19 particles in the world right now would weigh if they were packed together in one place. They approximated that an infected individual carries around 10 billion to 100 billion SARS-CoV-2 particles when the disease is at its peak.
According to their study, if all of the SARS-CoV-2 particles in the world were gathered then they would weigh just as much as an apple or a young toddler. As each individual carries billions of these particles so given a range of 1 million to 10 million infections during the course of the pandemic, the collective weight of SARS-CoV-2 particles would be between 0.1 kg and 10 kg.
Ron Milo, a professor in the Department of Plant and Environmental Sciences at the Weizmann Institute of Science in Israel, tried to show the significance of that amount of weight by saying that “Taking a view from a larger historical context, from the standpoint of leverage, an atomic bomb is less than 100 kg [220 Ibs] of fissile material. And yet, look at the destruction that is wrought”.
He further said that “here we are talking about a super-tiny mass of viruses, and they are completely wreaking havoc on the world”. Milo is the senior author of the study and is working with co-lead author Ron Sender, a doctorate student in Milo’s lab. The researchers approximated the number of SARS-CoV-2 particles in one human by taking the previously known measurements from rhesus monkeys and multiplying the number of virus particles present per gram of tissue in rhesus monkeys with the mass of human tissues.
This gave them an estimate of the number of virus particles in human tissues. From previous calculations based on the virus’s diameter, they already knew that each viral particle has a mass of 1 femtogram (10 raised to the power -15 gram). Using the mass of each particle and the number of estimated particles, they calculated that each person, at peak infection, carries about 1 microgram to 10 micrograms of virus particles.
They also found out that during a single host infection the virus would gather around three mutations per month that is consistent with the known evolution rate of SARS-CoV-2. The duo concluded by saying that “We hope this research will initiate new thoughts and new experiments”. They published their findings in a study in the journal Proceedings of the National Academy of Sciences.