At a recent meeting between the Cuban president and health experts and scientists, the progress made in our country's pneumococcal conjugate vaccine development program was presented.
To learn more about this promising line of research led by the Finlay Vaccine Institute (IFV), part of the BioCubaFarma Business Group, Granma spoke with Dr. Darielys Santana Medero, head of the project linked to this topic, which the entity has been working on for more than 20 years.
Pneumococcal disease is caused by the bacterium Streptococcus pneumoniae (pneumococcus) and can lead to serious invasive diseases, such as acute meningitis and pneumonia complicated by pleural effusion, as well as sinusitis, bacterial otitis media, and bloodstream infections, Santana Medero said.
"These conditions occur more frequently and severely in children under five years of age and also in the elderly. In particular, the first two mentioned and sepsis can have a severe course and cause death.
"Thus, invasive pneumococcal disease usually reaches a mortality rate of around 8% in children with meningitis and 5% in cases of pneumonia, figures that are higher in elderly people."
According to estimates by the World Health Organization (WHO), despite high vaccination coverage worldwide, these diseases cause approximately 1.6 million deaths annually across the globe, including nearly 800,000 children under five years of age. The highest number occurs in developing countries.
In Cuba, pneumonia and influenza are the fourth leading cause of death. A significant proportion of these deaths are due to the bacterium Streptococcus pneumoniae.
Dr. Darielys Santana pointed out that pneumococcus is transmitted through respiratory droplets and secretions, especially when coughing or sneezing. Many people, mainly children, can be carriers of the bacterium without showing symptoms, which facilitates its spread.
Pneumococcus is the second leading cause of community-acquired pneumonia requiring hospitalization (after respiratory syncytial virus), both in adults and infants.
"Today, there are more than 100 different serotypes of this bacterium, of which 20 to 30 are the most relevant in the onset of the aforementioned diseases. Hence the importance of developing multivalent vaccines that guarantee greater protection for the most exposed population groups."
MERITORIOUS TECHNOLOGICAL COMMITMENT
Under the premise of being a research, development, and production center, the IFV was founded in 1991 and currently supplies eight vaccines to the National Health System and several active pharmaceutical ingredients necessary for the manufacture of other products of this type manufactured in Cuba.
Among its main lines of work, the Program for the Development of Multivalent Conjugate Vaccines against Pneumococci, launched more than two decades ago, stands out. Its most prominent result is the creation of the Quimi-Vio® (heptavalent) pneumococcal vaccine, registered in 2024 by the Center for State Control of Medicines, Equipment, and Medical Devices (Cecmed).
According to Dr. Darielys Santana, the vaccine protects against seven of the most common serotypes worldwide and those most prevalent in the country.
"The process of obtaining it faced a high degree of scientific, chemical, analytical, and technological complexity, factors that highlight the relevance of this result of Cuban biotechnology.
"The evidence observed demonstrates the favorable impacts reported with its application. Suffice it to say that between 2017 and 2019, 93% of children between the ages of one and five were vaccinated in the province of Cienfuegos.
"Whereas previously the mortality rates from meningitis and other invasive diseases caused by pneumococcus were around 3.1 and 9.1 per 10,000 infants in that age group, after vaccination was completed, and despite the subsequent impact of COVID-19, the rates fell to zero and have remained so to date.
In the case of children admitted to intensive care due to severe pneumonia, the incidence rate among those vaccinated is 3.14, compared to 123.67 among those not vaccinated, he stressed.
Yury Valdés Balbín, PhD in Chemical Sciences and director general of the IFV, told this newspaper that the greatest effort in the pneumococcal conjugate vaccine program is currently focused on achieving, during 2026, the health registration of the Quimi-Vio 11 vaccine candidate, which incorporates four new serotypes with a significant incidence in the onset of diseases caused by the bacterium.
"It is unique in that it targets older adults as well as infants. Phase II-III clinical trials are currently being conducted in both age groups, with adults in health institutions in Havana and children in the provinces of Cienfuegos, Santiago de Cuba, and soon in the capital as well.
"This vaccine candidate is undergoing accelerated development, based on the same conjugation and carrier protein technology platform as the Quimi-Vio® (heptavalent) vaccine. This approach has made it possible to move forward rapidly with the clinical evaluation strategy, following the demonstration of the safety and immunogenicity of the latter."
In older adults, the schedule is a single dose, while in infants it is three doses at two, four, and 11 months of age, said Dr. Valdés Balbín.
He emphasized that the IFV is also working on another vaccine candidate against 16 serotypes (Quimi-Vio 16), which adds five more in terms of epidemiological relevance compared to its immediate predecessor. It is currently undergoing evaluation in laboratory animals.
All trials of pneumococcal conjugate vaccines take place in primary health care, and this poses a huge challenge that only a social system like ours is capable of taking on, stressed the Director General of the entity.
The name Quimi-Vio pays well-deserved tribute to the memory of scientist Violeta Fernández Santana, one of the main researchers and promoters of this project, who died in November 2011.
