A group of researchers from the National Influenza Center, located in Valladolid, has detected which population groups are most unprotected against the monkeypox virus, whose outbreak in 2022 triggered alarms, and, therefore, They provide which would be the priority segments when taking public health measures and prioritizing vaccination.
The work, published in the American scientific journal ‘Emerging infectious diseases’, one of the journals with the greatest impact that crosses European borders, has studied by age groups the possible protection against mpox (monkey pox) among the population vaccinated against smallpox. Specifically, it has focused on a cohort of 162 people over 50 years of age, with a control group of ten people under 40 and unvaccinated, to detect the presence of residual antibodies from the Smallpox vaccine, which was the serum that was supplied. in Spain until the year 1980.
Attending cases
The director of the center, José María Eiros Bouza, and the scientific and Virological Surveillance manager, Iván Sanz Muñoz, explained this to Ical, who specified that this study, to the extent that cases continue to be treated and that a vaccine still exists, would allow delimit the target population in possible vaccination campaigns and, also, refine the health professionals to whom it could be addressed, since its transmission is by contact.
The unprecedented study in Spain concludes that in people over 50 years of age the amount of antibodies is notable and their presence increases with age. It also shows that protection falls at 80 years of age, which indicates that, in potential vaccination campaigns, this population group should also be included as a target group.
Antibodies and seroprevalence
“We have seen that more than 57 percent of the population studied had antibodies and the seroprevalence varied by age group,” with a greater presence in people between 71 and 80 years of age, where the percentage shoots above 78 percent, although it decreases gradually if you go back to 50 years, says Sanz.
A possible explanation, beyond the fact that the immunological memory had disappeared, is that the vaccination was not identical throughout the 30 years in which vaccination was carried out with greater intensity in Spain, and also in Europe. It slowed down as the incidence of smallpox fell, to the point that, if six million vaccines were administered in Europe in 1961, in the 1970s, “when very few cases were reported and people lost interest in vaccination”, the annual doses decreased to 725,000, at the beginning of the decade; 500,000 in the middle, and barely 100,000 in 1979, which was when the disease was considered eradicated.
historical reflection
As a result of the monkeypox outbreak last year, this hypothesis was raised by a group of researchers from the National Influenza Center, one of the three centers that exist in Spain designated by the World Health Organization. Some publications commented that the smallpox vaccine induced a cross protection of approximately 85 percent, and it was observed that the highest incidence occurred in the young population. However, national records showed that 813 cases, about 12.5 percent, occurred in people over 50 years of age, a population for which the vaccine was once indicated.
The group relied on its experience in seroprevalence studies to find out if a certain infectious agent, which emerges as new or reappears after a period of silence, has immunized the population; aware of its capacity and track record in monitoring infectious diseases subject to vaccination, where it is a “pioneer” in certain historical zoonoses such as hydatidosis, brucellosis and francisella. He also addressed research taking advantage of his work in the evaluation, for 40 years, of the response to vaccination in institutionalized people in Castilla y León.
Reflection on vaccines
“What we did was reflect historically on what had happened at the end of the 18th century, when Edward Jenner discovered vaccines in the United Kingdom. He did a conceptual exercise, which is useful to us, but which is an inverse phenomenon. He sees that milking cows were immunized against human smallpox, and what we have seen is that the circulation of a human virus could protect against an animal virus », summarizes Eiros to Ical.
The work is signed by ten researchers, all from the National Influenza Center and doctors at the Clínico Universitario and Universitario Río Hortega hospitals in Valladolid. In addition to José María Eiros and Iván Sanz, the head of the Clinic’s Preventive Medicine and Public Health Service, José Javier Castrodeza Sanz; Silvia Rojo Rello, Laura Sánchez de Prada and Marta Domínguez-Gil González, associates of Mircobiology; Virginia Fernández Espinilla, head of the Preventive Medicine and Public Health Section; Cristina Hernán García, assistant in Preventive Medicine and Public Health; Javier Sánchez Martínez, Senior Technician of the Clinical Diagnostic Laboratory, and Raúl Ortiz de Lejarazu, Scientific Advisor.
A group of researchers from the National Influenza Center, located in Valladolid, has detected which population groups are most unprotected against the monkeypox virus, whose outbreak in 2022 triggered alarms, and, therefore, They provide which would be the priority segments when taking public health measures and prioritizing vaccination.
The work, published in the American scientific journal ‘Emerging infectious diseases’, one of the journals with the greatest impact that crosses European borders, has studied by age groups the possible protection against mpox (monkey pox) among the population vaccinated against smallpox. Specifically, it has focused on a cohort of 162 people over 50 years of age, with a control group of ten people under 40 and unvaccinated, to detect the presence of residual antibodies from the Smallpox vaccine, which was the serum that was supplied. in Spain until the year 1980.
Attending cases
The director of the center, José María Eiros Bouza, and the scientific and Virological Surveillance manager, Iván Sanz Muñoz, explained this to Ical, who specified that this study, to the extent that cases continue to be treated and that a vaccine still exists, would allow delimit the target population in possible vaccination campaigns and, also, refine the health professionals to whom it could be addressed, since its transmission is by contact.
The unprecedented study in Spain concludes that in people over 50 years of age the amount of antibodies is notable and their presence increases with age. It also shows that protection falls at 80 years of age, which indicates that, in potential vaccination campaigns, this population group should also be included as a target group.
Antibodies and seroprevalence
“We have seen that more than 57 percent of the population studied had antibodies and the seroprevalence varied by age group,” with a greater presence in people between 71 and 80 years of age, where the percentage shoots above 78 percent, although it decreases gradually if you go back to 50 years, says Sanz.
A possible explanation, beyond the fact that the immunological memory had disappeared, is that the vaccination was not identical throughout the 30 years in which vaccination was carried out with greater intensity in Spain, and also in Europe. It slowed down as the incidence of smallpox fell, to the point that, if six million vaccines were administered in Europe in 1961, in the 1970s, “when very few cases were reported and people lost interest in vaccination”, the annual doses decreased to 725,000, at the beginning of the decade; 500,000 in the middle, and barely 100,000 in 1979, which was when the disease was considered eradicated.
historical reflection
As a result of the monkeypox outbreak last year, this hypothesis was raised by a group of researchers from the National Influenza Center, one of the three centers that exist in Spain designated by the World Health Organization. Some publications commented that the smallpox vaccine induced a cross protection of approximately 85 percent, and it was observed that the highest incidence occurred in the young population. However, national records showed that 813 cases, about 12.5 percent, occurred in people over 50 years of age, a population for which the vaccine was once indicated.
The group relied on its experience in seroprevalence studies to find out if a certain infectious agent, which emerges as new or reappears after a period of silence, has immunized the population; aware of its capacity and track record in monitoring infectious diseases subject to vaccination, where it is a “pioneer” in certain historical zoonoses such as hydatidosis, brucellosis and francisella. He also addressed research taking advantage of his work in the evaluation, for 40 years, of the response to vaccination in institutionalized people in Castilla y León.
Reflection on vaccines
“What we did was reflect historically on what had happened at the end of the 18th century, when Edward Jenner discovered vaccines in the United Kingdom. He did a conceptual exercise, which is useful to us, but which is an inverse phenomenon. He sees that milking cows were immunized against human smallpox, and what we have seen is that the circulation of a human virus could protect against an animal virus », summarizes Eiros to Ical.
The work is signed by ten researchers, all from the National Influenza Center and doctors at the Clínico Universitario and Universitario Río Hortega hospitals in Valladolid. In addition to José María Eiros and Iván Sanz, the head of the Clinic’s Preventive Medicine and Public Health Service, José Javier Castrodeza Sanz; Silvia Rojo Rello, Laura Sánchez de Prada and Marta Domínguez-Gil González, associates of Mircobiology; Virginia Fernández Espinilla, Head of the Preventive Medicine and Public Health Section; Cristina Hernán García, assistant in Preventive Medicine and Public Health; Javier Sánchez Martínez, Senior Technician of the Clinical Diagnostic Laboratory, and Raúl Ortiz de Lejarazu, Scientific Advisor.
