Experience in the fight against COVID-19
Michael Saag: We have learned how to effectively treat patients
About a year ago, an outbreak of a mysterious disease was recorded in China. The COVID-19 pandemic has claimed more than a million lives and caused tremendous damage to the global economy. All this time, research on this infection was going on and methods of treatment were developed..
On the fight against COVID-19 Russian service «Voices of America» said Michael Saag, professor of medicine and infectious diseases at the University of Alabama at Birmingham.
For more than three decades, Michael Saag has been studying viruses and treating patients with COVID-19 (he also had it): «We know much more about the virus today than we knew when the first reports of infection in Wuhan appeared. We know more about the structure of the virus and how it triggers a response from the immune system. Thanks to this, it was possible to create many potential vaccines, some of which are now in the final stages of clinical trials..
We managed to better understand the mechanism of action of the coronavirus and the specific pathologies caused by it. We now know that the virus attacks the cells of the respiratory tract, turning them into “factories” for the production of their copies. Through the circulatory system, viruses spread throughout the body. The virus causes the formation of microthrombi, which lead to a number of problems even at the earliest stage of the disease..
We also now know a lot more about how the immune system responds to the virus and what symptoms of COVID-19 occur. When the immune system realizes that a person has been attacked by a virus, it tries to counterattack, but its response turns out to be excessive, which causes severe symptoms of the disease..
Margot Gontard: Have the methods of treating patients with COVID-19 changed during this time??
Michael Saag: Initially, we focused on the use of hydroxychloroquine – based on a small series of trials in France. There have been attempts to use it together with the antibiotic azithromycin. Some have talked about the benefits of using hydroxychloroquine with zinc. We now know that this is not the most effective treatment..
We also learned about the possibility of using remdesivir, a drug that blocks the multiplication of viruses in the body. This quality is extremely valuable and is also very close in action to the drugs that we usually use to fight HIV / AIDS and hepatitis C. Its mechanism of action is also similar to that of acyclovir, which we use against herpes. Remdesivir really works. So far, it has been mainly used in the treatment of hospitalized patients, since it must be administered intravenously, five days in a row twice a day, which is difficult to do if the person is not in the hospital..
Another major breakthrough was the use of dexamethasone steoride. Nowadays, it is often used in the treatment of hospitalized patients and it is perhaps our most effective weapon in the case of moderate to severe patients. Many hospitals use it together with remdesivir. They are most effective when used in the early stages of hospitalization..
We have also learned to use antithrombotic agents frequently and early in the treatment of hospitalized patients. We have noticed that approximately ten percent of patients with COVID-19 can develop blood clots in the leg and other parts of the body, which can lead to stroke or heart problems. Regular use of antithrombotic agents in treatment saves lives and helps people recover.
There are many other drugs emerging now. The most notable are the preparations based on monoclonal antibodies. These are antibodies created in a laboratory and converted into a drug that can be administered intravenously. The most famous use case – while treating the President of the United States. Then, in addition to remdesivir and dexamethasone, the drug company Regeneron was also used, which developed two different types of antibodies that attack the virus. This drug also works as an antiviral, prevents the virus from entering cells and infecting them..
At this stage, we can say that we have learned how to effectively treat patients. At the very beginning of the pandemic, we were in a hurry to quickly hospitalize patients and connect them to ventilators. But, as we gained experience, we realized that patients became much better in cases where we managed to avoid mechanical ventilation and alleviate their condition with the help of other methods and drugs..
M.G .: Will an effective vaccine be created??
M.S .: It is possible that the vaccine will never appear. People need hope, and the vaccine – it is, above all, hope. I am also full of hope. But I have been working with HIV / AIDS for decades. The epidemic began in the early 1980s and the US Secretary of Health announced in 1984 that we would have a vaccine by 1986. But there is still no vaccine, because sometimes viral infections are more complicated than they initially seem.
On the other hand, the structure of the coronavirus is simpler than that of the HIV / AIDS virus – it does not mutate so often, its strains have a more or less similar outer shell, which we can attack with a vaccine. We also have evidence that antibodies can stop the virus from attacking human cells and preliminary evidence that a vaccine can help generate such antibodies and the necessary immune response..
But even if we assume that we have an effective vaccine and we are able to vaccinate a large number of people, there are a number of possible difficulties. First, there may be people who, for various reasons, do not want to be vaccinated. People have the right to refuse vaccinations, which could set us back in the fight against the pandemic. Second, the vaccine is unlikely to protect everyone. Some people will not receive protection from the virus. This means that there will remain a risk that they could contract COVID-19, and that we will still need to find treatments and have the necessary drugs. It also means that we will still need to continue to wear masks, maintain social distance and wash our hands frequently..
We hope that herd immunity will develop over time. The virus has the ability to infect people while they are vulnerable to its effects. When enough people have acquired immunity and are no longer infected, the virus begins to subside. It’s like a fire that goes out when it runs out of fuel or oxygen. The more people who have immunity, the faster the fire will burn out.
But we must remember that the immunity that occurs after a natural disease with coronavirus does not last forever – six months or a year after recovery, people can get sick again. Vaccination, we hope, in addition to ensuring the formation of a one-time immunity, will also make it possible to strengthen it every, say, six months or a year with the help of re-vaccination. This will allow the immune system to remain and prevent the spread of the virus..
Collective immunity will not develop if we just let everyone get sick. First, to reach the 70% percent required for herd immunity, it will take 220-230 million people in the United States to get sick. And even in this case, herd immunity cannot be formed, because immunity from a natural disease does not last long enough. Not to mention that approximately six million people could die as a result..
M.G .: What treatments for COVID-19 do you consider promising?
M.S .: We will need to have at our disposal treatment options that can be applied in the earliest stages of the disease, as soon as symptoms appear. For example, like using oseltamivir to treat influenza. This drug works best when given to a person within 24 hours of the onset of symptoms. If we had such a remedy to fight COVID-19, the world would be very different, even without a vaccine. Work is currently underway on such drugs, and there are several drugs of this type that are under development. Another possible option – drugs based on artificially created antibodies, similar to the drug of the pharmaceutical company Regeneron.
M.G .: The possibility of using the plasma of people who have recovered from COVID-19 is widely discussed. You can tell about it?
M.S .: The idea is that blood is taken from a person who has had a coronavirus infection and recovered, and plasma is released from it, in which there are antibodies. Then this plasma can be administered to another. In the first month or two after recovering from the disease, I had a large number of such antibodies. The problem is that different people develop different amounts of antibodies, and they may react differently to the virus: some may develop very strong antibodies that aggressively attack the virus, while others may have weaker ones. This makes the use of plasma less effective treatment than the use of drugs created in the laboratory. Thus, when you give such a drug to different people, you can be sure what exactly you are giving, what dose of the substance and what properties it has. Such drugs are the future of immunotherapy.
M.G .: There are many and varied symptoms of COVID-19. How easy it is at an early stage to understand from the symptoms that a person has this particular disease?
M.S .: The symptoms of COVID-19 are indeed often not too specific. In many ways, symptoms are generated as a result of the response of the immune system, which fights the virus. It causes chills and fever, coughing, difficulty breathing, and diarrhea. However, similar symptoms are caused not only by COVID-19, but also by a number of other infections. How, then, to distinguish COVID from, say, flu? – So much with the test. Fortunately, tests have become better and more accessible. In our hospital, there were cases when it turned out that a person was sick with both the flu and COVID-19. Knowing the exact diagnosis is fundamental to determining exactly how a person should be treated. Testing plays a key role in this process..
M.G .: Can we quickly return to normal life after the vaccine arrives??
M.S .: We will have to wear masks, maintain social distance, avoid crowds, and wash our hands frequently – for at least a few months or even a year after a successful vaccine emerges. We don’t know how many people she can protect. It might be 70 percent, it might be 90 percent. In the case of vaccination, it is not known whether we will be among the 90 percent that will acquire immunity to the coronavirus, or 10 percent that the vaccine will not be able to protect. In addition, we do not yet know how long this immunity will last and how often it will be necessary to re-vaccinate. While we study this, we will need to take precautions. We still have a lot to learn.
Let’s not forget that the pandemic started less than a year ago. Less than a year! And we are already talking not only about successful treatment, but also about a vaccine. It’s incredibly fast! See how things were with HIV / AIDS. AIDS was first discovered in June 1981. The virus that causes it was not known until March 1983, the test was not available until May 1985, and the methods of treatment were not until 1987.…. We didn’t have a successful therapy until 1996, or rather 2000. And forty years later, we still don’t have a vaccine.