Sunday, September 26

Covid-19: how long did it take to find the vaccine for some diseases (and why this coronavirus is a historical case)


  • Camilla Costa and Cecilia Tombesi *
  • BBC World News

Caption,

Technology has been key in the development of vaccines in the last century, and covid-19 has written a new chapter in that history

The COVID-19 vaccine developed by Pfizer and BioNtech (one of the phase 3 vaccines) went from concept to reality in just 10 months.

It is an unprecedented span of time in history.

But how does it compare to other vaccines, and why has a vaccine never been so fast before?

The University of Oxford in the United Kingdom compared the time elapsed between the identification of the bacteria or viruses that cause 16 diseases and the year a vaccine to combat that particular disease was approved in the United States.

They chose this country because it is where most immunizations were authorized for the first time.

In addition to covid-19, the graph shows diseases that have a high mortality, according to the World Health Organization (WHO), and for which vaccination is recommended.

Some ailments have vaccines in testing but are not yet licensed.

The comparison shows how the process of creating vaccines can take decades and how the current pandemic has been an exception to this paradigm.

Why are some vaccines developed and approved faster than others?

At one extreme is the malaria, for example, that although its relationship with the parasite was discovered 140 years ago Plasmodium, there is still no definitive vaccine.

In 2015, the European Medicines Agency approved the use of the RTS, S vaccine to fight infection in children in Africa, but its use is still limited to pilot projects in some countries.

“The case of malaria is complicated. The life cycle of Plasmodium It is difficult to find a specific target for the vaccine, “researcher Samantha Vanderslott, one of the authors of the Oxford study, explained to BBC Mundo.

This is because the parasite infects human red blood cells and that makes it less detectable to the immune system.

At the other end of the graph is messenger RNA vaccine (MRNA) against covid-19, manufactured by the companies Pfizer and BioNTech.

This was recently approved in the UK and is under review by the FDA, the US regulatory agency.

However, Russia was the first country in the world to register a COVID-19 vaccine.

Self-produced, the Sputnik V it was approved in August and began to be administered in December in the capital, Moscow.

The results of the studies to verify its efficacy and safety are still incomplete and have not been submitted for review by the international scientific community.

“Some people may wonder if the speed of approval of the vaccine means that they have skipped stages. But it is important to keep in mind that the research that has been done since the SARS and MERS epidemics has contributed to those results. Furthermore, they have been obtained. more resources, more funding and more support from governments and pharmaceutical companies due to the pandemic, “says Vanderslott.

In addition to malaria, there are diseases such as dengue, Zika, Ebola, infection by cytomegalovirus (CMV) or AIDS that still do not have a definitive vaccine.

“With the exception of CMV infection and AIDS, which are global problems, most of these diseases are insect-borneThey also depend on sanitary measures for their eradication and affect poorer countries, “Cristina Bonorino, professor at the Federal University of Health Sciences of Porto Alegre and member of the Brazilian Society of Immunology (SBI), tells BBC Mundo.

“However, the vaccine is a product made by pharmaceutical companies that are expensive to develop. They are not investing in vaccines because they believe they are not profitable.”

According to Bonorino, if the countries that most need vaccines cannot invest resources, the decision to produce them or not ends up being up to the companies themselves. For this reason, many of these diseases do not have priority, although the technology to combat them already exists.

“HIV, for example, is a complex virus but we know how to create immunity. We do not have a vaccine because companies have products that control the problem and that sell very well, such as antiretrovirals. Why are they going to invest in one? vaccine that costs hundreds of millions of dollars? “

How technological innovations play a key role

According to the Oxford University study, the decrease in time to develop vaccines can be attributed to technological advances of the last century.

For example, bacterial cultivation techniques in the laboratory led to the creation of vaccines against diphtheria and tetanus in the early 1900s.

Similarly, advances in virus culture in the laboratory made vaccines against polio, measles, rubella, and smallpox possible in the 1950s and, recently, discoveries in molecular biology and chemistry led to vaccines against hepatitis B, flu, pneumonia and meningitis.

Caption,

The Pfizer / BioNTech vaccine took just 10 months to develop.

Covid-19 vaccines are expected to write a new chapter in this story, according to the two experts.

“The most promising of these vaccines are the technologies used, especially in those of mRNA and in those of viral vectors. They could be used as platforms to develop immunization for other diseases. It is very encouraging”, says the Oxford researcher.

SBI’s Cristina Bonorino agrees, but believes more results are still needed.

“The mRNA vaccine was a great achievement, but you have to see its effectiveness in the population as a whole. But this method can be revolutionary because it is much simpler than the ones currently used. I usually say that if this vaccine works, it could even be done in space “, he concludes.

*With the collaboration of Analía Llorente.

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