Professor of Biology and Entomology at Evan Pugh University, Eberley Professor of Biotechnology, Director of the Huck Institutes of Life Sciences, Pennsylvania
Assistant Professor of Biology, Pennsylvania State
Not new authors, not consulted, or no parts obtaining, or no information on the organism to research.
The first anti-HIV drug brought dying patients back from the brink. But as eager doctors raced to deliver the miracle drug to new patients, the miracle faded. In every patient, the drug only works for a short time.
It turned out that the drug was very good at killing the virus, but the virus was better at developing resistance to the drug. A spontaneous mutation in the genetic material of the virus prevented the drug from performing its function, and thus the mutated viruses were able to multiply violently in spite of the drug, making the patients sick again.. It took another decade before scientists found anti-evolution treatments.
Could the same thing happen to the COVID-19 vaccine? Could a safe and effective vaccine in initial trials fail because the virus is evolving out of trouble? As evolutionary microbiologists who have studied a poultry virus that has developed resistance to two different vaccines, we know that such an outcome is possible.. We also think we know what it takes to stop it. COVID-19 vaccines may fail – but if they had certain properties, they wouldn’t.
For the most part, humankind has been lucky: most human vaccines have not been undermined by microbial evolution.
For example, the smallpox virus was eradicated because it had never found a way to evolve around the smallpox vaccine, and no strain of the measles virus emerged that could overcome the immunity caused by the measles vaccine..
There is one exception. The bacteria that cause pneumonia have developed resistance to the vaccine. Developing this vaccine and replacing it with another was costly and time consuming, with seven years lapse between the initial emergence of resistant strains and the licensing of the new vaccine..
No further failures of human vaccines have occurred yet, but there are hints that viruses, bacteria, and parasites could or could develop in response to vaccination. Escape mutations that are able to evade vaccine-induced immunity are regularly seen in the microbes that cause hepatitis B and whooping cough..
For human diseases such as malaria, trypanosomiasis, influenza and AIDS, it was difficult or impossible to develop vaccines because the microbes that cause these diseases evolve so rapidly. In agricultural settings, animal vaccines are often undermined by viral evolution.
If SARS-CoV-2 develops in response to the COVID vaccine, there are several directions it could take. The most obvious thing is what happens with the influenza virus. Immunity works when antibodies or immune cells attach to particles on the surface of the virus. If the mutations in those particles change on the surface of the virus, the antibodies will not be able to hold it tightly and the virus can escape.. This process explains why the seasonal flu vaccine needs to be updated every year. If this happens, the COVID vaccine will need frequent updating.
However, development may go in other directions. It would be better for human health, for example, if the virus evolved into stealth mode, perhaps by slowly multiplying or hiding in organs where immunity is less active.. Many pathogens that cause chronic, barely noticeable infection have taken this path. They avoid detection because it does not cause severe disease.
The more dangerous path may be if the virus develops a way to reproduce more quickly than the immunity the vaccine generates.. Another strategy is for the virus to target the immune system and suppress the immunity caused by the vaccine.
Many microbes can live inside the human body due to their remarkable ability to interfere with our immune systems. If SARS-CoV-2 has ways to partially disable human immunity, the COVID vaccine may favor the mutants who do it better..
Before the emergence of COVID, we both compared vaccines that continue to work with those undermined by pathogen development.
It turns out that anti-evolution vaccines really have three advantages. First, it is very effective in suppressing virus reproduction. This stops further transmission. No repetition, no transmission, no evolution.
Second, anti-evolution vaccines stimulate immune responses that attack many different parts of the microbe at the same time.. It is easy for one part of the virus to mutate and run away from targeting. But if many sites are attacked simultaneously, immune escape requires many separate escape mutations to occur simultaneously, which is nearly impossible.. This has already been demonstrated in the laboratory for SARS-CoV-2. There, the virus quickly developed resistance to antibodies targeting a single site, but it struggled to develop resistance to a group of antibodies, each targeting several different sites.. .
Third, development-resistant vaccines protect against all the circulating strains, so that others cannot fill the void when competitors are removed.
There are about 200 COVID candidate vaccines in various stages of development. It’s too early to tell how many of them have these anti-evolution traits.
Fortunately, there is no need to wait for the licensed vaccine to be detected. A little extra effort during vaccine trials can go a long way to knowing if a vaccine will be resistant to evolution.. By scanning people who received the experimental vaccine, scientists can see how suppressing levels of the virus are. By analyzing the genome of any virus in vaccinated people, it might be possible to see an evolutionary escape in action. And by taking blood from the vaccines, we can determine in the laboratory the number of sites on the virus that are attacked by the immunity caused by the vaccine..
The world clearly needs COVID vaccines. We think it’s important to keep track of those who will continue to work. It is likely that many candidates in the current portfolio will. Let’s define the ones that are in clinical trials and go with them. Vaccines that provide only temporary relief leave people vulnerable and take time and money to replace. It may also cancel other vaccines if viruses that are resistant to many vaccines appear simultaneously.
The world today suffers from insect-resistant mosquitoes, crop pests, herbicide-resistant weeds, and the antibiotic resistance crisis. History does not need to repeat itself.
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Corona virus, severe acute respiratory syndrome
World News – African Union – The evolution of the virus could undermine the COVID-19 vaccine – but this can be stopped
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