Respiratory syncytial virus (RSV) is one of the last remaining childhood diseases without an approved vaccine. nonetheless, in recent years, the siege of this virus (the main cause of bronchiolitis) closed and some of the biggest pharmaceutical companies in the world struggle to dominate a potential market. multimillionaire that for at least six decades added one failure after another.
In the last months and, especially, after the arrival of the Covid whose hygiene measures (masks, isolation) disturb the normal and natural model of infection-vaccination, which gives rise to a greater incidence, the laboratories are working against the clock. first get this inoculation and fight against a virus that kills about 100,000 babies every year and it infects almost all minors in their second year of life.
Sanofi, Janssen o In us Vaccination three of the nine laboratories that are part of this race have achieved it first pediatric RSV vaccine. Three were cited, together with Advaccine Biotechnology Companyis the only company with clinical trials in phase 2. Codagenix, Intravacc, Moderna, British hospital SIIPL, St. Jude and scientists at the Pontifical Catholic University of Chile are still working on phase 1. None of the drug companies have phase three trials (PATH, May 2023), so the arrival of what is already considered one of the most successful and profitable vaccines in recent decades – after the SARS-CoV-2 vaccine – could still take several years and pharmaceutical companies in the middle of a war to open a new era. in the fight against this virus.
nonetheless, after decades and little progress, this year there was big news in relation to this shot. On May 22, the Food and Drug Administration (FDA) recommended full approval for Pfizer’s respiratory syncytial virus (RSV) vaccine. for women in the last trimester of pregnancy. If approved, Pfizer’s jab would come The world’s first vaccine that protects infants against RSV but only from birth to the first six months of life, The company was informed in a statement. Minors from half a year on would continue unprotected. Last year, 2022, GSK voluntarily halted development of another vaccine in pregnant women. nonetheless, on May 4, the FDA gave Arexvy the green light (GSK), the world’s first vaccine against VRS for the elderlys.
Six decades of vaccine research
The road to achieving a pediatric RSV vaccine is a “long and winding” road. It was abruptly stopped by the event of 1966, when 31 infants were vaccinated with a formalin-inactivated virus vaccine (Kim HW, Am J Epidemiol 1969). Although the infants developed antibodies against RSV, 23 of the vaccinated became infected and the disease was more severe in them than in the unvaccinated children, since 18 of them were hospitalized and two died. All this, together with the poor immune response against RSV in infants under 6 months, has led to the fact that, until now, this age group has been excluded from developing vaccines against this virus.
It was not until 2013 when researchers Barney Grahan and Jason McLellan –which would later play a key role in the development of the vaccine against SARS-CoV-2– determined the structure and spatial conformation of the S1 protein of this virus and managed to create, by introducing mutations, different stabilized versions of the prefusion F protein. , which induced potent neutralizing antibodies. This important fact was the weapon that started the race to achieve an effective vaccine. But so far, only four clinical trials are in phase two of development and with different platforms: 1) live attenuated nasal vaccine for children between 6 and 24 months; and 2) non-virus vectored recombinant vaccines, such as adenovirus 26, for children between 12 and 24 months of age, as shown in the previous quadrant.
In Spain, it is estimated that RSV infections each year cause between 15,000 and 20,000 pediatric emergency visits and 7,000 to 14,000 hospitalizations. The number of children who die from RSV infection in our country is between 70 and 250 per year, according to data from the Spanish Association of Pediatrics.
Last fall, hospitals experienced another critical moment due to this childhood epidemic. In some communities, such as Galicia and Madrid, visits to the Emergency Department for this cause doubled, and in November there was a peak of 540 per 100,000 people, with a worrying incidence rate in children. from 0 to 4 years of 70.8%according to the comprehensive surveillance report on acute respiratory infections in Spain (SiVIRA).
This situation generated some alarm and, as a result, some autonomous communities took the decision, “at their own expense”, to announce the vaccine in the coming season, “because they heard that a vaccine would already be ready”, report reliable sources. in the sector.
The Community of Madrid anticipated in March 2023 that it will incorporate vaccines to prevent childhood bronchiolitis next fall, Catalonia announced the same although it did not foresee a date, and Galicia went further and promised in a statement that “Galician Health will be the first in the world to incorporate the respiratory syncytial virus (RSV) vaccine into its vaccination schedule”. “It’s going to start pouring in autumn in the same year, before the time of the greatest impact of the respiratory syncytial virus,” added the letter.
Faced with this situation, the experts consulted ensure that “a bubble of information has been created with this problem when no more vaccineseven if we are close.” In addition, it is seen as very unlikely that next fall we will have one of them. It must be remembered that Beyfortus (nirsevimab), from Astrazeneca, approved last week by the Interministerial Commission on Price Medicine, is not a vaccine but an antibody that provides defense against the virus, “but does not generate them in the child ».