Is a new pandemic possible? Conclusions of US scientists

A scientific article by American virologists about the ability of variants close to the MERS-CoV coronavirus to use the same receptor for binding on the cell surface as SARS-CoV-2 does not indicate an impending pandemic. The authors experimented with artificially created proteins.

As reported by BAKU.WS, this was stated to TASS by Doctor of Biological Sciences, Professor of the Department of Virology at the Faculty of Biology of Lomonosov Moscow State University, Nikolai Nikitin.

"Statements about a new potential agent that will cause a pandemic are, to put it mildly, premature. The authors did not discover America in the article. There are coronaviruses that can cause a new pandemic. But 'catching' that particular one in advance is a very unlikely prospect," Nikitin clarified in a conversation with TASS.

Earlier, some media outlets, citing an article by American scientists in the journal Nature Communications, spread information about the discovery of a new coronavirus that could potentially cause a pandemic. Rospotrebnadzor on Sunday stated that this information does not correspond to reality and that the research concerns already known viruses. At the same time, the situation with coronavirus infection in the Russian Federation is stable and under control, the press service of the organization told journalists.

"The authors of this fundamental work created an artificial system based on the spike protein of the Middle East Respiratory Syndrome coronavirus (MERS, caused by the MERS-CoV virus), and the main receptor necessary for binding to molecules on the cell surface was replaced with sequences from other coronaviruses. Unlike the coronavirus we are familiar with, MERS-CoV uses a different receptor to enter human cells. The main conclusion of this work is that some coronaviruses belonging to the same subgenus as MERS-CoV can use the same receptor as SARS-CoV-2 - angiotensin-converting enzyme type 2. However, we cannot say that these variants will cause a pandemic tomorrow," noted the virologist.

He pointed out that the authors conducted experiments with artificially created "chimeric" proteins and recreated the infection mechanism in laboratory conditions far from natural ones.

Infection from camels

MERS-CoV caused an outbreak of coronavirus infection in Saudi Arabia in 2012. It was transmitted to humans from dromedary camels and had a high mortality rate (about 35%), the scientist recalled. The causative agent of this infection still circulates in the world and periodically appears in camel farm workers.

"Now the mortality rate from infection is approaching zero thanks to emergency response measures. Fundamental research in this area is very important: it provides information about the evolution of viruses and, most interestingly, about the probabilities of them overcoming the interspecies barrier," the researcher explained.

The MSU professor recalled that over the past decades, thousands of coronaviruses from various animals have been discovered and studied, including bats, which serve as natural reservoirs for this virus.

"For a coronavirus to cause a pandemic, many factors need to coincide. Some viruses can enter human cells but cannot replicate in them due to a number of reasons, such as the work of the cellular immune system. Patient survival and the ability to transmit infection are also important issues. For example, with MERS and SARS, mass spread was unlikely, in part due to the poor adaptation of viruses to human cells and high mortality. Therefore, so far we only see works based on the study of molecular mechanisms of virus interaction with cells," he concluded.