Is There A Cure Or Vaccine For The Coronavirus Soon?

2023 Author: Abraham Higgins | [email protected]. Last modified: 2023-11-27 23:16

Is there a cure or vaccine for the coronavirus soon?

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The new coronavirus infection COVID-19 (caused by the SARS-CoV-2 virus) is sweeping the world and spreading panic. A reasonable question arises: when will there be drugs and vaccines? And then there are two news. First (good): work is underway, a large number of trials of drugs and vaccines are registered. Second (slightly worse): everything takes time. What are the main difficulties and what is happening on the market? We understand our material.

Finding a cure

Epidemics of diseases caused by coronaviruses have already happened. Humanity has faced SARS (SARS, 2002-2003) and Middle East respiratory syndrome (MERS, 2015), so the knowledge and experience accumulated during these outbreaks may be useful this time too. In addition, we can draw on research and treatment options for other viral diseases.

In order for an effective drug for COVID-19 to appear, there are, globally speaking, two strategies. The first is to see what antiviral drugs are already available and try to use some against a new infection, the so-called "reprofiling". Some of them have a wide spectrum of action, and different types of viruses may have some similarities. This is why this strategy sometimes works. The results of the first attempts at repurposing known drugs are already being used in clinical practice.

Despite some lack of evidence, Remdesivir (originally developed for the treatment of Ebola) is already being used in the United States to treat COVID-19. It is also found in the clinical guidelines of some European countries, for example, in Spanish. Chloroquine, an old malaria drug, is showing efficacy in treating coronavirus and may be included in future versions of clinical guidelines, according to new Chinese research. However, the results of clinical trials of Kaletra (a cocktail of HIV protease inhibitors) were disappointing: in a study of 199 people, statistically significant differences were found between the control group with standard maintenance treatment and the drug. In addition, the use of this drug caused more side effects.

In parallel, other drugs are being tested around the world, including the popular Oseltamivir, which is already used to treat influenza. All drugs that can affect one or another stage of the life cycle of the SARS-CoV-2 virus (for example, block entry into the host cell or prevent the virus from multiplying) have a chance to be useful in the fight against a new infection.

The second strategy is the development of a new drug. Here everything is more complicated, since first you need to do screenings, which at the first stage are carried out on computers using mathematical modeling, and then promising molecules are examined in the laboratory, on isolated viruses and cell cultures. After that, preclinical testing is carried out, which includes animal models, which is also associated with problems. It is not always possible to find a suitable model, because not every human virus infects animals, and the course of the disease in different organisms may differ. Then scientists need to conduct several phases of clinical trials, that is, to test the drug in different conditions and dosages on groups of people and see the dynamics. Normally, the development of a new drug takes at least 7-10 years, and sometimes even longer. Due to the urgency, some stages can be skipped or shortened, but everything has a price: this increases the risk of getting an ineffective drug with many side effects.

The journal Nature recently published an article looking at new drugs for the treatment of COVID-19 that are now in development around the world. Preparations based on monoclonal antibodies (antibodies produced by immune cells belonging to the same cell clone, that is, originating from one plasma progenitor cell - ed.), As well as proteins that can bind to the virus and prevent its penetration into cage.

Finding a vaccine

One of the most effective ways to fight epidemics is vaccination. This is how smallpox and polio (type 2 strain) were defeated and the spread of many other diseases was reduced. The vaccine is also important because, according to some reports, in the US and Europe, the number of people aged 30-50 who are sick with COVID-19 in a severe form is increasing - thus, it is better not to hope to “get sick easily”, but to protect yourself with the help of vaccination.

To create a vaccine, it is important to know how the virus enters the cell, which protein of the virus creates an immune response, and how antibodies will be formed. In addition, scientists expect what will be the basis of the vaccine: an attenuated virus, an isolated protein or its fragments, a recombinant protein engineered by genetic engineering methods. There are many questions, and not all of them have answers, although new publications and data appear daily.

Almost all vaccines that are currently being developed are in preclinical trials. The main goal of vaccines is to select a protein specific for this virus or a fragment of it, to which the immune system can efficiently produce antibodies that help to quickly recognize and destroy a real virus when faced with it. Of the approximately 20 candidate proteins in phase I (human safety studies) clinical trials, two potential vaccines have emerged so far:

MRNA-1273 Vaccine Candidate: The vaccine builds on previous developments in SARS and MERS. The study included 45 healthy volunteers 18–45 years old. The recruitment of participants ended on March 19. The developer is Moderna (USA), and the research is supported by the National Institute of Allergy and Infectious Diseases NIAID.

Vaccine candidate Ad5-nCoV: a recombinant (hybrid, i.e., genetically engineered) coronavirus vaccine that includes a type 5 adenoviral vector (Ad5). Sample: 108 participants 18-60 years old who will receive 3 different doses (low, medium and high). The recruitment of research participants is still ongoing. The vaccine developer is CanSino Biologics (China).

In addition, it is possible that repurposed monoclonal antibodies developed against previous coronaviruses (SARS severe acute respiratory syndrome virus and MERS virus of the Middle East respiratory syndrome) could provide passive immunity until the advent of a vaccine specifically against COVID-19.

Scientists at the State Research Center of Virology and Biotechnology "Vector" have also begun testing a vaccine against Covid-19, according to Russian news sources. But we are talking, again, about preclinical tests on cell cultures and laboratory animals.

How long can it take for a full cycle of vaccine production, from the first tests to the actual vaccination of the population?

The development and testing of a vaccine takes as much time as the development of a drug, because it is very dangerous to release an incompletely studied drug. The vaccine may cause an overly strong immune response or allergic reactions, or it may not be effective enough. All of this is being studied before regulatory authorities agree to register a vaccine and begin widespread use. If we talk about examples when a vaccine was created faster than in the usual 8-10 years, you can recall the story of Ebola. The vaccine was developed in about 3 years, but on the other hand, this virus has been studied for a long time and there was more data on it than on SARS-CoV-2.

Vaccines, like drugs, are also routinely tested on animals to make initial safety and efficacy checks. Most often, mice and primates are used for this. However, changes in the rules for vaccines against COVID-19 are now being discussed, perhaps some preclinical tests can be significantly reduced. As we said above, animals do not always get infected and get sick in the same way as humans, and finding a suitable model also takes time, otherwise the data obtained will not bring any practical benefit.

After preclinical tests, you need to move on to clinical ones. They usually take place in three stages (phases): in the first phase, safety is studied and the maximum allowable doses are determined, in the second, the final effective dose is selected and the effectiveness is confirmed, and in the third, the effectiveness is already finally proven. Even if the vaccine has passed all the research and entered the market, then you still need to establish and scale up mass production: it will take millions of doses! It all takes time. Therefore, the promises that a vaccine will be released somewhere in a few months and it will really help are rather big words than reality, especially if you do not neglect the necessary stages, do high-quality research and comply with the requirements of regulators.

In the context of the rapid spread of the pathogen, the International Coalition of Medicines Regulators (ICMRA) held a workshop and put on the agenda the reduction of preclinical stages in a number of cases, as well as special control over informing volunteers participating in vaccine research, and the need to monitor their condition as closely as possible. … All of these measures are designed to shorten vaccine development time while minimizing potential harm to human safety.