The version of Coronavirus that surfaced in Britain late last year was shocking for several reasons. It came as vaccines offered a glimpse of the end of the epidemic, threatening to smash those hopes. It was far more contagious than the earlier variants, leading to a rapid increase in hospitalizations. And perhaps most surprising to scientists: it had sparked a large constellation of mutations overnight.
A coronovirus typically acquires mutations at a slow-but-steady rate of about two per month. But this variant named B.1.1.7 acquired 23 mutations that were not on the virus previously identified in China. And 17 of them had developed all at once, deviating from their most recent ancestor shortly thereafter.
Experts said there is only one good hypothesis for how this happened: at some point the virus may have infected someone with a weakened immune system, causing it to adapt and develop inside a person’s body for months before being transmitted to others. It is possible. “This seems to be the most likely explanation,” said a virologist at the University of Cambridge. Ravindra Gupta said.
If true, the idea has implications for vaccination programs, particularly in countries that have not yet begun to vaccinate their populations. A virologist and infectious disease physician at the University of Michigan, Drs. Adam Loring said that people with immune systems – such as cancer patients – should be vaccinated first. The faster the group is protected, the lower the risk of their next body coming into incubators for the next supercharged mutants.
Dr. “We must give the best shot to protect this population, to be used literally and figuratively,” said Loring.
He said that it can be complicated. For the same reason that these people do not mount a strong immune response to the virus, vaccines may not work well in them. So they may need to be treated with a cocktail of monoclonal antibodies, he said.
Like other viruses, the coronovirus collects mutations every time. The overwhelming majority of those genetic glitches are negligible and transient. In most people, an active infection lasts only about a week, not long enough for the virus to have more than one notable mutation, if any.
Researchers made coronoviruses more contagious or capable of dodging the immune system are extremely rare, researchers said Study published Last week in science. “But if they do happen, and if they can spread, it’s open season,” said Katrina Lithgow, an evolutionary biologist at the University of Oxford, who led the study.
From months to years, the virus can bind many such mutations together. Scientists can observe this slow evolution using molecular “clock” that capture changes over time. But in a person with a weakened immune system, this timeline can be very fast.
“If we look at multiple time points through that course of infection, and we look at the virus population in that patient, we see – every time – different variants popping up with a larger turnover rate , “Said Vincent Munster, a virologist at the National Institute of Allergy and Infectious Diseases who led one of the studies.
If one of these types of mutations that have acquired significant mutations is transmitted to someone else, it can quickly spread through the population and appear to have moved out of nowhere – as in variants Is the case that gave Britain the wall, and perhaps others identified in South Africa. And Brazil.
“It is a very good hypothesis that they have come from people with persistent infections,” Dr. Lithgow said of the variants. “By keeping the infection rate low, you’re going to reduce the number of infected people who are infected and reduce the likelihood of it happening.”
“Immunocompromised” is a vague term encompassing a wide range of conditions – from diabetes and rheumatism to leukemia and lymphoma – and experts disagree about which conditions may change.
Some say the list should include older people as well as those who take drugs that suppress the immune system and none that produce a strong set of antibodies.
“We learn from vaccines that talk about antibodies,” said Paul DuPreaux, director of the Vaccine Research Center at the University of Pittsburgh. “It is very important to keep an eye on those who are immune-suppressors, who do not have a fully functional immune system.”
Dr. Loring said he was most concerned about people with blood-related cancers such as leukemia, but did not have strong concerns about taking drugs such as Hamira or Enbrel, which are used to treat rheumatoid arthritis.
“It’s a different kind of immunosuppression that I’m not sure it would be, but no one knows for sure,” he said.
Some people with a weakened immune system are known to transmit Other viruses For a long time, Drs. Loring mentioned. A man is shed in england Poliovirus for at least 28 years. Others have had frequent infections with norovirus or influenza.
“We’ve been dealing with this for a long time,” he said. “But like everything with Kovid, we’re dealing with it extensively.”
He and other experts emphasized that regardless of the risks, it is important not to stigmatize or blame people who compromise the immune system. Instead, he said, their focus should be on limiting exposure to the virus.
“Let’s get people vaccinated, let’s do good distancing, let’s do good masking,” Dr. DuPreaux said. “Anything we can do to stop the virus from spreading is very important indeed.”