How do scientists create vaccines for new viruses?Comments
As concern about the COVID-19 coronavirus outbreak spreads across the world, scientists are working to develop a vaccine.
Over 3,800 worldwide have died of the virus, which first appeared in the Chinese city of Wuhan in December. The World Health Organization (WHO) has flagged the outbreak as an international emergency.
When the virus began, Chinese experts unravelled its DNA in record time.
Now, hundreds of scientists around the world have begun to create a vaccine, which, according to WHO estimates, could take a year and a half to produce.
The development of a vaccine can take years, with no certainty of result. Some diseases, such as HIV, have been studied by scientists for decades without a vaccine to be found.
Vaccines vary in composition, method of production, purpose and methods of application. Attenuated vaccines, in use since the 1950s, are considered traditional. The virus is weakened for months or even years under laboratory conditions until it is deprived of pathogenicity - the ability to cause an infectious process.
Vaccines for measles, rotavirus, or polio are attenuated. The creation of such a vaccine takes about 12 years on average.
"This is a time-consuming method because you need to be able to prove that the virus is indeed inactivated," Frederic Tanguy, professor at the French Pasteur Institute, told Euronews.
"In a crisis situation, there is no time to use such methods."
Attempts to accelerate this process led to the creation of the so-called recombinant vaccines. Scientists, using genetic engineering, transfer the antigens of a new disease into an already existing and tested one. The hepatitis B vaccine, for example, is recombinant.
Specialists from the Pasteur Institute, one of the world's leading epidemiological institutions, are using the already well-studied measles virus in their studies on COVID-19, Tanguy said.
"This is a relatively quick way, because we can create a measles vaccine and reproduce it in a million copies every year. This is a well-established production process," Tanguy explained.
In addition to well-established methods for creating a vaccine, experts identify methods that have not proved their effectiveness. For example, creating a vaccine based on DNA or RNA virus.
"These methods are very attractive, because with their help the vaccine can be made in three months. But so far they have not proved their effectiveness," Tanguy said.
"We cannot cut the path"
Before getting to pharmacy shelves, vaccines must go through several stages of development and testing in animals and humans.
"The vaccine needs to undergo fairly sophisticated regulatory compliance tests so that we can really guarantee that it is a safe, good quality product that has proved effective," said Dr. Dina Pfeifer, head of the WHO's Europe disease prevention program.
Any medicine, both for humans and for animals, must comply with a set of rules for pharmaceutical manufacturers called Good Manufacturing Practice or GMP.
"This is a long process that runs counter to the need to fight new diseases," Dr. Pfeifer admits.
"But we cannot cut the path. Vaccine development should be consistent with national and international regulations. There are good reasons for this."
Polio and GMP
GMP was developed by the World Health Organization in 1967 to prevent a recurrence of a situation similar to the one that occurred with the polio vaccine of American developers Cutter Laboratories in 1955. Without waiting for a license, the laboratory produced a batch of the drug that did not pass the necessary control.
This batch of vaccinations contained a live polio virus and out of 120,000 vaccinated children, 40,000 developed a mild form of polio. In 56 children, the vaccine caused paralysis. This polio outbreak due to medical error led to the death of five people.
Although the certification process can take a long time, some coronavirus vaccine developers believe that they will be able to set up the production of an active vaccine in a few years.
The Pasteur Institute hopes that their COVID-19 vaccine will be available next winter. The vaccine is expected to be tested in humans as early as September.
Scientists are also working on a universal vaccine against coronaviruses, which can be modified as a seasonal flu shot.
"We don’t know if we can do it. We do not have evidence yet, but we think it is possible," Tanguy said.
According to experts, every year 570 billion dollars are spent on stopping outbreaks of dangerous diseases.
According to Professor Tanguy, the most difficult part in developing a vaccine, which costs an average of $2.8 billion, is the search for funding.
"It is very expensive... and such things are difficult to fund, because we are dependent on manufacturers. Manufacturers have their own strategy, it is not always beneficial for them to introduce new technologies," Tanguy explained.
WHO estimates that up to 650,000 people die each year from respiratory illnesses associated with the usual seasonal flu. Among the most dangerous viruses for which there is no vaccine yet, the Middle East Respiratory Syndrome (MERS) has a mortality rate of 30 to 40%.
"Although all attention is now focused on the new virus, there are other diseases that should be controlled and which need to be addressed more effectively," Dr. Pfeifer believes.
In total, the WHO list of diseases that need to be defeated as a matter of priority is 11 items long.
"Scientists are working on a variety of vaccines", Dr. Pfeiffer said. "There is news on the HIV vaccine, which, unfortunately, did not produce the necessary results. There are diseases that cause a lot of problems, for example, malaria, Zika virus, dengue fever. They spread rapidly and kill many people in some parts of the world. These are the vaccines that we would like to pay more attention to."