There is a global push to develop a vaccine to slow the spread of Kovid-19, and experts expect that many will be ready in 2021. Yet with one, coronovirus is likely to remain with us for years, demanding long efforts to find a cure for those who still fall ill.
In humanity’s millennium-long struggle against the virus, prevention from vaccines has been far more successful than treatment with drugs. In fact, modern medicine has come up with only one true cure for a viral infection. For many serious infections, the best approach is a cocktail of drugs that throw motion bumps in front of the infection.
It is a weak medical arsenal, which seems to be at ease with our viral enemies.
“They cannot survive, they are not independent, they cannot process food, take in oxygen, reproduce themselves without a master support system being parasitic inside a living cell , “Said Paula Cannon, a professor at the KK School of Medicine at the University of Southern California.
So why do viruses hurt humans so much? Outside the body, a vigorous hand wash is enough to kill many. Inside, the immune system’s long memory is enough to make most of it work.
This is when we run into a new virus that starts causing problems.
The coronovirus, SARS-CoV-2, is the latest in a procession of new infectious diseases that have surprised the world in recent years. The best hope against this is a vaccine, which can catch them before they prevent infection.
A vaccine is, essentially, a shortcut to immunity. But if we do not have immunity and get sick, then things get more complicated. Because viruses cannot survive on their own, they hijack our cells to multiply. This parasitic dependence makes them harder to treat with most conventional medicines. A virus is so interrelated with its host that it is difficult to hurt the other without hurting one. SARS-CoV-2 infects the airways and lungs – the things we need to breathe.
This leaves an inappropriate option according to Cannon. “I can kill the virus, but I have to kill you to do it.”
For some vaccines, such as measles, sufficient herd immunity has been created that the virus can no longer catch and spread in populations. In the best case, as with smallpox, shots have driven the disease out of the human host population and into extinction.
Treating an active infection is another matter. There is one drug treatment for only one virus: Hepatitis C. Because of the “kill the virus, kill the host” problem, the best bet is often to slow down the viruses that the body’s own defenses can do their job.
“When we can’t kill a virus, the best thing we can do is prevent it from replicating,” said Raid Dweck, chairman of the Cleveland Clinic Respiratory Institute in Ohio. “All we can do is that the duration of the infection is short, not a cure. Even when the infection is over, the patient recovers more than he cured.”
Remedisvir, the only drug of widespread use that targets SARS-COV-2, works by messing with the ability to replicate the virus. This causes errors when the virus tries to copy itself. It was also a product of luck: the drug was originally developed as a treatment for Ebola, but was not very effective and the outbreak in Africa made it difficult to study for its manufacturer, Gilead Sciences Inc. made.
Clinical trials have shown that Remedisvir can help hospitalized Kovid-19 patients recover more quickly. But this is not a cure, and it is unlikely that there will be any time soon.
“It’s powerful and specific drugs to do that can stop coronovirus in its tracks,” Cannon said. “Most drug candidates fail.”
In the future, patients will likely receive a cocktail of treatments attacking viruses and others that help keep them stable. Currently, Remedisvir is part of a cocoon of care that includes only other clear therapies, steroid dexamethasone, as well as fluid-like standard fare, and invasive approaches when required to include patients on ventilators. Other drugs layered topically: blood thinners and experimental approaches to calm a potentially hyperactive immune system.
As new approaches reach the market, they will be added to the mix. But for most people, an already formidable and current approach to any viral treatment would have to be improved: the human immune system.
Greatest save of all time
It is not a coincidence that many infections lasted about two weeks, Cannon said. How long does it take for the immune system to kick into gear.
“Our immune system is the best drug maker in the world,” she said. “Whether you had measles as a 5-year-old or Kovid as a 50-year-old, our immune system includes this vast library of potential antiviral approaches that provide protection.”
Cannons said that there are anti-infection proteins, biological drugs, produced to drive away foreign invaders. The body has the ability to make millions and millions, activating just one when a virus is bound – then producing it over a period of about 14 days.
“This is when the immune system gets the upper hand,” Cannon said. “The blood contains a lot of antibodies, coating the virus. They do a good job of neutralizing the virus. Ultimately, antibodies win the day.”
Those antibodies do not completely fall to their initial low levels. Instead, they remain on reserve and patrol for years, in case of endangerment. If this happens, the response does not take 14 days.
“If you get the same virus, the infection doesn’t go away because antibodies kick in,” Cannon said. “You don’t even get sick. That’s why, as with most viruses, you get them once and you’re immune in the future.”
It is this process that mimics the vaccine. Man-made vaccinations provide the immune system with a piece of the virus, providing enough for the body to activate against a potential threat without making the body truly ill. The immune system is thus alert and capable of preventing infection, rather than fighting one.
This is the approach behind another wave of therapies in development for even more serious Kovid-19 patients. Drugmakers have figured out how to develop antibodies that mimic the natural substances the body produces, and experimental drugs based on them are coming from Resigneron Pharmaceuticals Inc., Roach Holding AG and Eli Lilly & Company.
But those treatments are likely to be reserved for the sickest, hospitalized patients. And those types of treatments are expensive – thousands of dollars for a course. Gilead’s hepatitis C drug, for example, cost $ 84,000, since it was approved for US sale in 2013. The development of Kovid-19 costs biotechnology medicines, such as thousands of dollars per course. Vaccines, on the other hand, are cheaper – and keep people away from more expensive care.
“Because we can’t treat them very well, the Cleveland Clinic’s Dweck said, the important thing is always prevention.” “Once you are infected, there is very little that we can support you through it or maybe shorten it a little bit. That’s why getting vaccinated is so important.”
There are hundreds of viruses that cause respiratory infections and are usually lumped together under the “common cold” banner. There are many coronations. The reasons we do not have treatment are because each is individual to individual and drug development is so expensive, often topping $ 1 billion per therapeutic. Each treatment must be tailored to a specific pathogen, following a tailor-made path so narrow that it would be nearly impossible. Already, thousands have failed.
And a cold? It usually goes on its own.
Comprehensive economics has historically worked against drugs for viral infections, leaving a gap in the type of innovation that has occurred, along with other profitable conditions such as cancer and heart disease. The most recent viral outbreak, which includes both SARS and MERS, both novel coronaviruses, as well as zika, led everyone to gain a foothold before new treatments.
“Think about it from the point of view of the Dallas company,” said James Cutrell, director of the Infectious Diseases Fellowship Program at the University of Texas Southwestern Medical Center, Dallas. “Infection is usually an acute disease that you are going to treat for a short period of time. If it is a rare infection, it may not be that many people who take it. When these other viruses start “There was a lot of interest in developing therapies. But once they died there was not enough for clinical trials.”
The economic impetus for drug manufacturers changed with the Kovid-19 epidemic, which is so widespread and so disruptive that a vaccine is seen as a social necessity. The US government, as part of its Operation Tana Momentum program, has entered into deals of about $ 10 billion with drug manufacturers to develop and manufacture several vaccines. The shots that come with him, and his successor, can be used worldwide for years.
It will also definitely not be the last new virus in the world.
“Science tells us that this virus is not unique, it is one of the many animals that roam in animals,” said Dweck. “There is no reason to think it won’t happen again.”
(Except for the headline, this story has not been edited by NDTV employees and published from a syndicated feed.)