Coronavirus vaccine: What if I already have a coronavirus vaccine?

Melinda Wener Moyer


As the world is waiting Coronavirus vaccine, Tens of thousands can die. However, some scientists suspect that the vaccine may already exist.

An astonishing new study in a niche area of ​​immunology suggests that certain live vaccines, which have been around for decades, are probably able to protect against coronaviruses. The theory is that these vaccines can reduce the likelihood that people will experience serious, and even any, symptoms if they catch it.

At more than 25 universities and clinical centers around the world, researchers have begun clinical trials targeting primarily healthcare professionals to determine if the live TB vaccine used for 99 years is called the Calmette-Guerin (BCG) vaccine. Is being tested and can reduce the risks associated with coronaviruses.

Another small but respected group of scientists is raising funds to test the potential protective effects of the 60-year-old live polio vaccine O.P.V.

It’s counterintuitive to think that old vaccines created to fight very different pathogens can protect against coronaviruses. The idea is partly controversial, as it challenges the doctrine of how vaccines work.

However, scientists’ understanding of the field of immunology, called innate immunity, has changed in recent years. Live vaccines made from live but attenuated pathogens (as opposed to killed vaccines using dead pathogens) suggest broad protection against infection in a way no one expected The number of studies to do is increasing.

“We don’t know what the outcome will be, but I think it affects the coronavirus,” said Jeffrey Siriro, a microbiologist and immunologist at Texas A & M University, who heads one of BCG. . trial. “The question is, how big is it?”

Scientists emphasize that these vaccines are not panacea. They may alleviate symptoms, but they probably do not eliminate them. And if that happens, protection will probably last only for a few years.

Still, “these could be the first steps,” said Dr. Mihinetea, an immunologist at the University of Radobud, the Netherlands, who is leading another clinical trial. “They can be bridges until we have the time to develop a particular vaccine.”

The first evidence suggests that a live vaccine may have been widely protected almost a century ago, but no one knew what to do with it. 1927, B.C.G. Immediately after, the Swedish Tuberculosis Association’s Karl Naslund found that children vaccinated with a live tuberculosis vaccine were three times less likely to die from the cause than children who were not.

“People cause this very low mortality rate among vaccinated children, B.C.G. vaccines cause nonspecific immunity,” he wrote in 1932.

Later, in clinical trials conducted in the 1940s and 1950s in the United States and the United Kingdom, researchers reduced non-accidental deaths by causes other than B.C.G. tuberculosis by an average of 25%.

Also, in the 1950s, Russian researchers, including Marina Borosirova of the Academy of Medical Sciences in Moscow, found that people who received the live polio vaccine had seasonal illnesses compared to those who did not. I have noticed that the odds are much lower that influenza and other respiratory infections. She and other scientists conducted clinical trials on 32,000 Russians to test their mysterious effects more carefully.

Among the individuals who received the live polio vaccine, they said, “the incidence of seasonal flu was reduced by 75%,” and is the son of Mr. Boroshirova, currently vice director of research for the US Food and Drug Administration. Said Konstantin Chumakov. Vaccine research And reviews.

Recent studies have shown similar results. In a 2016 review, World Health Organization, A team of researchers, B.C.G. Concludes, along with other live vaccines, “reduces overall mortality more than might be expected through its impact on the disease being prevented.”

WHO. I have long been skeptical of these “non-specific effects” because many of them have been involved in observational studies that do not establish cause and effect. However, in a recent report incorporating new results from several clinical trials, tissues described the effects of non-specific vaccines as “likely and common”.

Dr Stanley Protokin, a veterinary professor and emeritus professor at the University of Pennsylvania who developed the rubella vaccine but is not involved in the current study, agreed. “Vaccines can affect the immune system beyond its response to certain pathogens,” he said.

Peter Aaby, a Danish anthropologist who has been criticized for finding the vaccine’s nonspecific effects for 40 years in Guinea-Bissau, West Africa, said the findings would be a turning point in the field. I’m looking forward to it. . “It’s a kind of golden moment in terms of actually taking this seriously,” he said.

The potential for vaccines to have non-specific effects is partly widespread, as we believed they work by stimulating the body’s highly specific adaptive immune system.

For example, after receiving a vaccine against polio, the human body creates an army of polio-specific antibodies that recognize and attack the virus before it catches it. However, antibodies to polio cannot fight off infections caused by other pathogens. Therefore, based on this framework, polio vaccines cannot reduce the risk associated with other viruses such as coronavirus.

But over the last decade, immunologists have discovered that live vaccines stimulate the innate immune system. They found that the innate immune system was trained by live vaccines to better repel various types of pathogens.

For example, in a 2018 study, Dr. Netea and his colleagues used B.C.G. or placebo to infect volunteers with a harmless version of the yellow fever virus. People who were given B.C.G. were able to repel yellow fever.

According to studies by Dr. Netea, live vaccines train the body’s immune system by initiating some stem cell changes. Among other things, the vaccine initiates the creation of small marks that help cells turn on genes involved in immune protection against multiple pathogens.

This area of ​​innate immunity is “one of the hottest areas of basic immunology today,” Dr. Robert Gallo Human Institute Co-founder of Virology at the University of Maryland School of Medicine Global virus network, A coalition of virologists from more than 30 countries. In the 1980s, Dr. Gallo as the cause of H.I.V.AIDS.

Dr. Gallo is a live polio vaccine as a treatment for O.P.V. coronavirus. He and his colleagues want to start a clinical trial in New York City and Maryland within six weeks.

O.P.V. is used daily in 143 countries, but not in the United States. The inactivated polio vaccine was reintroduced here in 1997 because one in 2.7 million live vaccines could actually develop polio.

However, OPV Americans who have previously been vaccinated against polio do not have this risk. “We believe this is very, very, very safe,” said Dr. Gallo. It is inexpensive, at a single dose of 12 cents, and does not require a needle because it is taken orally.

Some scientists have expressed concerns about whether these vaccines increase the risk of a “cytokine storm,” a fatal inflammatory response observed in a few people weeks after being infected with coronavirus. I am. Dr. Netea and others take these concerns seriously, but said they didn’t anticipate the problem. For one thing, the vaccine is given only to healthy people, not those already infected.

Also, B.C.G. It may actually be possible to increase the body’s initial immune response in a way that reduces the viral load in the body so that an inflammatory response does not occur. “It may help reduce infections from the start,” said Dr. Moshe Arditi, director of the Center for Infectious and Immune Disease Research at Cedars-Sinai Medical Center in Los Angeles, which heads one of the trial departments. Said.

The science on this is still in its infancy. Some preprints (scientific papers not yet peer-reviewed) published over the past few months have been published by B.C.G. You can protect from coronavirus. For example, B.C.G. Mortality is reported to be low in countries that regularly vaccinate children in the United States. However, these studies can be biased and difficult to interpret. It is impossible to know if vaccination or anything else provided protection.

Such research “is at the bottom of the hierarchy of evidence,” said Dr. Christine Stabberben, who is raising funds for the B.C.G. trial in Denmark. She added that the protective effect of doses of BCG given to adults decades ago on infants might be significantly different from the protective effect the vaccine could provide when given to adults during outbreaks. .

“In the end, only clinical trials will give the answer,” said Dr. Netea.

Thankfully, the answer will come soon. Initial results from ongoing trials may be available within the next few months. If these researchers are right, these old vaccines can spend us time and save thousands of lives, but we are working on the development of new vaccines.