SAN DIEGO – From South Africa to Brazil to California, the list of sites associated with new strains of the coronavirus is growing, with fears that viral versions could disrupt the spread of the vaccine.
The concern comes at a time when most Americans have not yet received the COVID-19 vaccine. That could change in late May, when President Biden said there would be enough vaccines for all adults in the United States. But until then, newer, faster-spreading coronavirus strains are likely to account for almost all cases.
Does this mean that all this effort is in vain?
According to local researchers with insight into non-viral immune systems. They say there is ample evidence that current vaccines work well against several known variants, that immunity is never a matter of all or nothing.
The manufacturers և federal regulators have announced that updating current vaccines to keep up with new strains will be relatively straightforward. Some of that work is already underway.
“My concern with one to 10 scale options is two or three,” said Dr. Mark Sawyer, an infectious disease specialist at Radi Children’s Hospital, who served on billboards suggesting that the Food and Drug Administration allow Moderna, Pfizer. Johnson & Johnson vaccines.
“I am just worried about them. They could create problems – they could create big problems. But at the moment, as far as we know, most of them seem to be manageable. ”
The emergence of new strains means that the coronavirus does what all viruses do – mutate.
Each time a virus infects a cell, it replicates its genetic material. But it is not a perfect process. Giving enough time, some examples will have a few random errors or mutations. It’s a bit like how you would make multiple typos after copying the same document 20 times.
Many mutations do not help the virus. Some can hurt it. But occasional mutations allow the virus to spread more easily from cell to cell or from person to person. And competing virus variants will eventually outperform less successful strains.
It’s the best survival on a microscopic scale.
“Viruses are intelligent creatures,” said Dr. Douglas Richman, a UC virologist in San Diego. “They accelerate Darwinian evolution.”
So it was only a matter of time before the coronavirus mutated into ways to make it more contagious. Many of the newer versions have mutations that help the virus attach more tightly to cells before they slip into them. Others are less vulnerable to antibodies, such as Y-shaped proteins, which can travel globally to the surface of the virus to block infection.
But these mutations did not make the vaccines useless.
One of the first ways to ignite fear was discovered in the UK last fall. The variant, also known as B.1.1.7, has been observed in San Diego ever since, and researchers expect it to eventually account for almost all COVID-19 cases in the county.
In late January, scientists reported that antibodies made by humans receiving the Pfizer vaccine had blocked the British version of the original strain found in Wuhan, China, infecting laboratory-grown cells equally well. The same goes for the Moderna vaccine.
For comparison, the antibodies of people who received the Moderna և Pfizer vaccine were less effective against the so-called South African strain. This is most likely the case with the strain first discovered in Brazil, which shares several key mutations.
Real-world test vaccine data developed by pharmaceutical giant Johnson & Johnson tell a similar story. The company’s vaccine was 72 percent effective in the United States, or 66 percent և 57 percent in Latin America և South Africa.
It is probably no coincidence that the vaccine has been less effective in areas where there is more concern, says Erika Olman Safir, a researcher at La Jolla Immunology. But the findings also underline one important point. Immunity is not white or white.
“The immune response is not really like a simple light switch,” Sapphire said. “It’s like a whole panel of dimmers,” he said. You have a lot of options, a lot of lights, if one gets a little dark, the others can still light up. ”
This is because vaccines elicit immune responses against different regions of the virus և rather than a single point, launching an antibody larva to stop the infection և an army of T cells to kill the infected cells before they release more virus.
A varied, perennial attack allows a mutation (or several) to disrupt the immune response.
“Most of these antibodies, most of these T cells, are still working,” said Sapphire, who is leading an international effort to test more than 200 antibodies to different strains of the coronavirus.
A greenish-brown cell that is heavily infected with a coronavirus, officially called SARS-CoV-2, is a cell that causes COVID-19 disease.
The most interesting of all recent reports to date is that the AstraZeneca COVID-19 vaccine is 21 percent more effective in a group of 2,000 South Africans, and only 10 percent against a rapidly spreading viral strain found in that country.
But while the study prompted the South African government to stop distributing the AstraZeneca vaccine, the country simply focused on using doses of Johnson & Johnson.
It is helpful to understand what the “effectiveness” of the vaccine means when interpreting these numbers. When the FDA says that any coronavirus vaccine should be at least 50 percent effective, the agency notes how well the vaccine compares to a placebo, preventing all of the symptoms of COVID-19, even mild headaches or coughs.
But keeping people alive and staying out of hospitals is definitely the key to restoring some of the pre-epidemic normalcy. And to that extent, COVID-19 vaccines are very effective. V onson և John onson, no one vaccinated in the AstraZeneca, Pfizer or Moderna trials died of COVID-19.
“When I got my first shot, I got this incredible sense of relief knowing the data. “I know that even if I do get infected, it is very unlikely that I will get any more mild symptoms,” said Richman, a 78-year-old UCSD virologist.
“It’s quite a bit of a blow to death or being on a respirator.”
Although COVID-19 vaccine manufacturers continue to neutralize doses, they are resuming their designs against viral variants.
Subject example. On February 24, Moderna announced that it had changed its vaccine to target the South African strain. The National Institutes of Health intends to test the safety of the modified vaccine and its ability to elicit an immune response in small clinical trials.
The FDA said it would be easier for companies to adapt the vaccine, which the agency has already approved. The main requirement will be that the antibody responses work on the modified vaccine as well as against the newer version, as earlier vaccine antibodies were against the original strain.
Such surveys could be done quickly by hundreds to hundreds of participants, rather than by tens of thousands of volunteers over several months.
“Confirmation does not require these huge studies,” Richman said. “It just has to show that you are getting the right immune response (targets).”
Scientists update the flu vaccine every year. And like the flu, researchers expect the coronavirus to survive. Even if the vaccine is spread, health precautions will significantly slow the spread of the virus.
Current vaccines have been developed and deployed in record time, less than a year after scientists discovered the coronavirus. This is a good sign that scientists are successfully updating the vaccine. But Sawyer of Ryd Children’s Hospital says there is a simple way to prevent any future: vaccinate as many people as possible as quickly as possible.
“Then we will have fewer options; we will not have to worry so much about California strains, South African strains or any other place you want to guess.”