Understanding Omicron – This is what scientists are doing now to understand the new coronavirus variants

Charlottesville, USA, December 10 (Conversation) The new SARS-CoV-2, first declared by the World Health Organization on November 26, 2021, as a “variant of concern” by scientists around the world. Competing to learn more about Omicron strains. Organization.

Authorities have asked whether recently emerging coronavirus variants are more contagious than Delta and other previous variants and cause more or less serious COVID-19, and whether current vaccines can prevent it. I warned that it would take a few weeks to find out.

Peter Kasson is a virologist and biophysicist at the University of Virginia, studying how viruses such as SARS-CoV-2 can invade cells and what they can do to stop them. Here he explains what lab-based scientists are doing to answer unanswered questions about Omicron.

Does previous immunity protect from Omicron?

These are the results of the important labs that everyone has been waiting for. How effective are the antibodies that people already have to fight Omicron? Are you protected if you get a booster shot? Or what if you were infected with COVID-19 and then vaccinated?

The goal is to see how well antibodies from real people infected with or vaccinated against COVID-19 can suppress the omicrons contained in the laboratory Petri dishes.

Scientists predict that antibodies from people exposed to other mutants will not work well against Omicron because of the mutation, but how bad it is to stop the virus, yet. You need to measure if it is enough.

To answer these questions, most researchers first create a version of the SARS-CoV-2 virus that can invade cells but not propagate. Some specialized laboratories with even higher levels of biosecurity use real viruses. Scientists add antibodies from the blood of people vaccinated with or recovered from COVID-19 to the virus. It is then mixed with human lung cells to see if the antibody can block the virus from infecting the cells.

In my laboratory, I am doing this kind of work with SARS-CoV-2 and other emergent viruses. Researchers have used these established techniques to test antibodies after COVID-19 recovery, as well as different vaccines and different mutants.

If antibodies made by people against previous variants cannot stop Omicron from infecting lung cells in the laboratory, those antibodies will probably not protect people around the world.

The initial early results are back, and antibodies against the early mutants appear to be less successful in blocking Omicron. The researchers collected antibodies from six people who were vaccinated twice each and another six who were vaccinated twice each and recovered from their previous COVID-19 infection.

Based on the amount of antibody needed to prevent infection, antibodies in both groups of people had about 40-fold worse omicron arrest than the original SARS-COV-2 strain. However, those whose immune system saw the virus three times, that is, those who received double vaccination and also recovered from COVID-19, had antibody levels high enough to stop the infection.

People who receive the booster vaccine will have a similar or higher level of immunity and will be at least moderately protected from Omicron. However, it should be tested. Pfizer states that the initial results are in line with this prediction, but the data has not yet been released. All of this work has not yet been peer reviewed and is still very preliminary.

Scientists say how good antibodies are in reducing “neutralizing titer” or blocking the virus in the laboratory, how to respond to the decrease in “vaccine efficacy”, or vaccination. It is necessary to determine how likely it is that the recipient will get COVID-19. Unvaccinated. Scientists know that better antibodies correspond to more effective vaccines, but accurate numerical relationships need to be determined.

How contagious is Omicron compared to Delta?

Past pandemic years have shown that infectivity, or infectivity, is an important factor in determining whether a variant of the coronavirus predominates. Delta’s transmissibility made it the predominant variant of the present, as it simply outperformed others. However, the situation can change over time.

The basic element of the virus’s “life” cycle is to invade cells, multiply the virus, and exit. Scientists can measure each of these stages in the lab and report which aspects of the mutant make it more or less contagious. With better binding to human cells, some mutations enhance the packaging of new viruses and the delivery of their genes when the virus invades the cells.

Laboratory-based science helps people understand the biology behind why mutants are more or less contagious, but nature is now conducting much larger real-world experiments. Disease surveillance data from the UK and other countries where Delta was dominant suggests that Omicron is gaining market share and may eventually replace Delta.

How this works depends on factors such as the number of vaccinated people and previously distributed variants, but this news is concerned about how good Omicron is. It has been.

Does Omicron make people more or less sick?

Again, this is a question that thousands of people infected with Omicron answer much faster than working in the lab. However, it is important to remember that natural experiments are not as carefully controlled as laboratory experiments. Working in the exact lab can help explain why Omicron is different, but the first answer here is from the hospital.

Laboratory-based scientists work with hospitals to analyze why patients infected with Omicron get more or less ill. Some early figures suggest that the first Omicron case is almost mild, but public health officials warn. Most cases of all COVID-19 variants are mild, and many of the cases infected with Omicron so far are young. The number of hospitalizations tends to increase somewhat after the initial increase in cases. Therefore, it will take some time to answer this question.

How are lab and public health data complemented?

The laboratory will provide the first results on immunoprotection against Omicron, which will be followed up with public health data that are likely to confirm the laboratory results. Public health data provide initial results regarding infectivity and disease severity, which are then explained by test results.

Even after the initial response from public health data is available, results that help understand why these changes have occurred and predict what future mutations will do are still important. How do authorities declare a variant of concern in the first place? It combines public health data with understanding from the lab.

What do we already know?

Variants of SARS-CoV-2 do not change the laws of physics and biology. They cannot jump over skyscrapers at once. Physical barriers such as premium masks and good ventilation block the virus. And perhaps the vaccine will continue to provide some protection. The question is, how much, does the world need to change the current vaccine, or does it need to provide more vaccines?

By Peter Casson, University of Virginia