A race against new tribes

Every virus mutates. The longer it is allowed to multiply, the more mutations it accumulates and the better the chance that it will learn to evade detection.

Therefore, especially in light of worrying new COVID-19 viral variants, a rapid and effective vaccination campaign is so essential.

“The message from home is that we’re really in a race right now, and it’s increasing our urgency to vaccinate the population en masse and protect the population before additional variants can develop and emerge,” said UC Dr Charles Chiu San said Francisco, whose lab is working with the Department of Public Health to look for viruses.

Scientists are particularly concerned about the mutation in a coronavirus variant called L452R, which comes on the heels of another strain from the UK that is now spreading rapidly in the US.

Why the concern? Location, location, location. As in real estate, the mutation of a virus can be the cause of it or break it.

The variant, which has been linked to multiple outbreaks in California, including major ones in Santa Clara County, has a significant change in the genetic instructions for the so-called “spike protein”, which the virus uses to enter our cells – and which the target of our only two vaccines.

It has not yet been proven that this new mutation makes the virus more transmissible, or that it avoids vaccines.

But it lives in a dangerous environment. And it causes the virus to act in suspicious ways. Only a month or so ago, this type of virus was quite uncommon. Now it represents about a quarter of all new cases undergoing genomic sequencing.

To find out, scientists are now growing the virus in a laboratory in San Francisco and watching them behave. Eight samples of the variant COVID-19 strain, from eight different people, are grown. Then these viruses will be injected into human blood samples from people being vaccinated or inoculated to see if they multiply.

It is well known that when a virus repeats, it sometimes makes random errors, called mutations, in its genetic code.

So far we have been happy. Unlike influenza viruses, the COVID-19 virus is usually fairly stable and accumulates only one or two mutations per month. This is because it contains a protein that serves as a proofreader, and corrects as many errors as it can find. And if it does change, most resulting variants are benign or even attenuated versions of the pathogen.

But there were several notable changes during the pandemic.

One of the first variants, a mutation called D614G. which increases infectivity and transmission appeared in China in March last year. It is now the dominant form of the virus, which is seen in 99% of all cases worldwide. This mutation – in the peak protein – is blamed for the explosion of the pandemic.

Another change in the virus, the removal of the genetic code, reduces the reliability of our tests. This is dangerous. Instead of testing positive, a sick person tests negative so that they do not realize their risk.

Another variant, first found in the UK, has 23 different differences compared to what is currently in circulation. One of these changes, a mutation in the vein protein called B117, makes it 50 to 74% more contagious.

Although this B117 virus is not more deadly than the existing strain, it can be more difficult to contain. In fact, more than 30 other countries have now noticed the variant, including the US. The good news is that it can be stopped by our vaccines. The ease of distribution suggests that we will have to vaccinate more people to bring about the so-called ‘herd immunity’.

A more alarming variant, called B1351 and announced by South Africa on 18 December, has eight to ten mutations for the ear protein. Based on the explosion of cases in South Africa, experts suspect that one of these mutations makes it more transmissible. According to the World Health Organization, it has been detected in 20 countries, but not yet in the US.

And what’s worse, another mutation in the strain seems to reduce the ability of antibodies to repel the virus – which can limit the effectiveness of vaccines.

“The lab data is very worrying for the possibility,” Chiu said.