Researchers found that, for now, a possible vaccine would work universally, against all strains of SARS-CoV-2. Despite the fact that the SARS-CoV-2 Coronavirus has presented small mutations in different parts of the world, it would not affect the application of a possible vaccine in a universal way.
This was identified by researchers from the Walter Reed Army Institute of Research in the United States, a biomedical institute administered by the US armed forces. They published their findings on August 31 in the journal of the National Academy of Sciences of that country.
“Our results suggest that, to date, the limited diversity observed in SARS-CoV-2 should not prevent a single vaccine from providing global protection,” the study notes. The researchers analyzed 18,514 coronavirus genomes, which came from 84 different countries. In this way, the scientists tracked the mutations as they appeared: first in China, then Europe and the United States.
The virus, however, showed low genetic diversity, said one of the study’s authors, Morgane Rolland. According to her, mutations have been a problem for other diseases. “Viral diversity has challenged vaccine development efforts for other viruses such as HIV, influenza and dengue, but global samples show that SARS-CoV-2 is less diverse than these viruses,” said Rolland.
In general, Coronaviruses have more complex replication systems, the study notes. Because of this, mutations are less frequent and replication tends to have high fidelity. “We can be cautiously optimistic that viral diversity should not be an obstacle to the development of a broadly protective vaccine against COVID-19 infection,” Rolland added.
The researchers did identify mutations in the Coronavirus. In fact, they identified two of them that have become dominant; that is, they are more likely to appear when the virus replicates. One of these mutations is called D614G and it happens in a key protein of the virus, which allows it to open cells and infect them. When testing this mutation, however, the researchers found no advantage over the immune system. The virus mutations, therefore, appear to be more by chance than by any adaptive advantage. “Until now, SARS-CoV-2 has evolved through a noisy and non-deterministic process,” the research notes.
One of the most likely reasons, according to the study, is that most people are vulnerable to the Coronavirus, so it can reproduce easily. Adaptive mutations (which give the virus advantages) are usually seen when more people have immunity, something that pushes the virus to adapt.