Freshly squeezed vaccines

4 06 2015

Microfluidic cell-squeezing device opens new possibilities for cell-based vaccines.

MIT researchers have shown that they can use a microfluidic cell-squeezing device to introduce specific antigens inside the immune system’s B cells, providing a new approach to developing and implementing antigen-presenting cell vaccines.

Such vaccines, created by reprogramming a patient’s own immune cells to fight invaders, hold great promise for treating cancer and other diseases. However, several inefficiencies have limited their translation to the clinic, and only one therapy has been approved by the Food and Drug Administration.

While most of these vaccines are created with dendritic cells, a class of antigen-presenting cells with broad functionality in the immune system, the researchers demonstrate in a study published in Scientific Reports that B cells can be engineered to serve as an alternative.

“We wanted to remove an important barrier in using B cells as an antigen-presenting cell population, helping them complement or replace dendritic cells,” says Gregory Szeto, a postdoc at MIT’s Koch Institute for Integrative Cancer Research and the paper’s lead author.

Darrell Irvine, a member of the Koch Institute and a professor of biological engineering and of materials sciences and engineering, is the paper’s senior author.


As cells pass through the CellSqueeze device at high speed, narrowing microfluidic channels apply a squeeze that opens small, temporary holes in the cells’ membranes. As a result, large molecules — antigens, in the case of this study — can enter before the membrane reseals. Courtesy of SQZ Biotech

A new vaccine-preparation approach

Dendritic cells are the most naturally versatile antigen-presenting cells. In the body, they continuously sample antigens from potential invaders, which they process and present on their cell surface. The cells then migrate to the spleen or the lymph nodes, where they prime T cells to mount an attack against cells that are cancerous or infected, targeting the specific antigens that are ingested and presented.

Despite their critical role in the immune system, dendritic cells have drawbacks when used for cell-based vaccines: They have a short lifespan, they do not divide when activated, and they are relatively sparse in the bloodstream.

B cells are also antigen-presenting cells, but in contrast to dendritic cells, they can proliferate when activated and are abundant in the bloodstream. However, their functionality is more limited: Whereas dendritic cells constantly sample antigens they encounter, a B cell is genetically programmed only to bind to a specific antigen that matches the receptor on its surface. As such, a B cell generally will not ingest and display an antigen if it does not match its receptor.

Using a microfluidic device, MIT researchers were able to overcome this genetically programmed barrier to antigen uptake — by squeezing the B cells.

Through “CellSqueeze,” the device platform originally developed at MIT, the researchers pass a suspension of B cells and target antigen through tiny, parallel channels etched on a chip. A positive-pressure system moves the suspension through these channels, which gradually narrow, applying a gentle pressure to the B cells. This “squeeze” opens small, temporary holes in their membranes, allowing the target antigen to enter by diffusion.

This process effectively loads the cells with antigens to prime a response of CD8 — or “killer” — T cells, which can then kill cancer cells or other target cells.

The researchers studied the squeezed B cells in culture and found that they could expand antigen-specific T cells at least as well as existing methods using antibody-coated beads. As proof of concept, the researchers then transferred squeezed B cells and antigen-specific T cells into mice, observing that the squeezed B cells could expand T cells in the spleen and in lymph nodes.

The researchers also say that this is the first method that decouples antigen delivery from B-cell activation. A B cell becomes activated when ingesting its antigen or when encountering a foreign stimulus that forces it to ingest nearby antigen. This activation causes B cells to carry out very specific functions, which has limited options for B-cell-based vaccine programming. Using CellSqueeze circumvents this problem, and by being able to separately configure delivery and activation, researchers have greater control over vaccine design.

Gail Bishop, a professor of microbiology at the University of Iowa Carver School of Medicine and director of the school’s Center for Immunology and Immune-Based Diseases, says that this paper presents a “creative new approach with considerable potential in the development of antigen-presenting cell vaccines.”

“The antigen-presenting capabilities of B cells have often been underestimated, but they are being increasingly appreciated for their practical advantages in therapies,” says Bishop, who was not involved in this research. “This new technical approach permits loading B cells effectively with virtually any antigen and has the additional benefit of targeting the antigens to the CD8 T-cell presentation pathway, thus facilitating the activation of the killer T cells desired in many clinical applications.”


Main squeeze

Armon Sharei, now a visiting scientist at the Koch Institute, developed CellSqueeze while he was a graduate student in the laboratories of Klavs Jensen, the Warren K. Lewis Professor of Chemical Engineering and a professor of materials science and engineering, and Robert Langer, the David H. Koch Institute Professor and a member of the Koch Institute. Sharei, Jensen, and Langer are also authors of this paper.

In a separate study published last month in the journal PLoS ONE, Sharei and his colleagues first demonstrated that CellSqueeze can deliver functional macromolecules into immune cells. The platform has benefits over existing delivery methods, including electroporation and genetically engineered viruses, which are limited to delivering nucleic acids. While nucleic acids can code a cell for a target antigen, these indirect methods have drawbacks: They have limited ability in coding for difficult-to-identify antigens, and using nucleic acids bears a risk for accidental genome editing. These methods are also toxic, and can cause cell damage and death. By delivering proteins directly into cells with minimal toxicity, CellSqueeze avoids these shortcomings and, in this new study, demonstrates promise as a versatile platform for creating more effective cell-based vaccines.

“Our dream is to spawn out a whole class of therapies which involve taking out your own cells, telling them what to do, and putting them back into your body to fight your disease, whatever that may be,” Sharei says.

After developing CellSqueeze at MIT, Sharei co-founded SQZ Biotech in 2013 to further develop and commercialize the platform. Just as the company has grown since then — now up to 13 employees — the device has also evolved. Sharei, now the company’s CEO, says that by improving the design and increasing the number of channels, the current generation has a throughput of 1 million cells per second.


Future steps

The researchers say they now plan to refine their B-cell-based vaccine to optimize distribution and function of the immune cells in the body. A B-cell-based approach could also reduce the amount of patient blood required to prepare a vaccine. At present, patients receiving cell-based vaccines must have blood drawn over several hours each time a new dose must be prepared.

Meanwhile, SQZ Biotech aims to reduce the footprint of its device, which could potentially lower the time and cost required to engineer cell-based vaccines.

“We envision a future system, if we can take advantage of its microfluidic nature, as a bedside or field-deployable device,” Sharei says. “Instead of shipping your cells off to this big, centralized facility, you could do it in your hospital or your doctor’s office.”

As the biology and technology become further refined, the authors say that their approach could potentially be a more efficient, more effective, and less expensive method for developing cell-based therapies for patients.

“Down the road, you could potentially get enough cells from just a normal syringe-based blood draw, run it through a bedside device that has the antigen you want to vaccinate against, and then you’d have the vaccine,” Szeto says.

This research was funded by the Kathy and Curt Marble Cancer Research Fund through the Koch Institute Frontier Research Program, the National Cancer Institute, the National Institute of General Medicine Sciences, and the Howard Hughes Medical Institute.


By Kevin Leonardi [en línea] Cambridge, MA (USA):, 04 de junio de 2015 [ref. 22 de mayo de 2015] Disponible en Internet:

Breast cancer vaccine shows promise in small clinical trial

29 12 2014

A breast cancer vaccine developed at Washington University School of Medicine in St. Louis is safe in patients with metastatic breast cancer, results of an early clinical trial indicate. Preliminary evidence also suggests that the vaccine primed the patients’ immune systems to attack tumor cells and helped slow the cancer’s progression.


A breast cancer vaccine designed by researchers at Washington University School of Medicine in St. Louis is safe in patients with metastatic breast cancer. Preliminary evidence from the small clinical trial, led by William Gillanders, MD, also suggests the vaccine helped slow the cancer’s progression.

The study appears Dec. 1 in Clinical Cancer Research.

The new vaccine causes the body’s immune system to home in on a protein called mammaglobin-A, found almost exclusively in breast tissue. The protein’s role in healthy tissue is unclear, but breast tumors express it at abnormally high levels, past research has shown.

“Being able to target mammaglobin is exciting because it is expressed broadly in up to 80 percent of breast cancers, but not at meaningful levels in other tissues,” said breast cancer surgeon and senior author William E. Gillanders, MD, professor of surgery. “In theory, this means we could treat a large number of breast cancer patients with potentially fewer side effects.

“It’s also exciting to see this work progress from identifying the importance of mammaglobin-A, to designing a therapeutic agent, manufacturing it and giving it to patients, all by investigators at Washington University,” he added.

The vaccine primes a type of white blood cell, part of the body’s adaptive immune system, to seek out and destroy cells with the mammaglobin-A protein. In the smaller proportion of breast cancer patients whose tumors do not produce mammaglobin-A, this vaccine would not be effective.

In the new study, 14 patients with metastatic breast cancer that expressed mammaglobin-A were vaccinated. The Phase 1 trial was designed mainly to assess the vaccine’s safety. According to the authors, patients experienced few side effects, reporting eight events classified as mild or moderate, including rash, tenderness at the vaccination site and mild flu-like symptoms. No severe or life-threatening side effects occurred.

Although the trial was designed to test vaccine safety, preliminary evidence indicated the vaccine slowed the cancer’s progression, even in patients who tend to have less potent immune systems because of their advanced disease and exposure to chemotherapy.

“Despite the weakened immune systems in these patients, we did observe a biologic response to the vaccine while analyzing immune cells in their blood samples,” said Gillanders, who treats patients at Siteman Cancer Center at Barnes-Jewish Hospital and Washington University. “That’s very encouraging. We also saw preliminary evidence of improved outcome, with modestly longer progression-free survival.”

Of the 14 patients who received the vaccine, about half showed no progression of their cancer one year after receiving the vaccine. In a similar control group of 12 patients who were not vaccinated, about one-fifth showed no cancer progression at the one-year follow-up. Despite the small sample size, this difference is statistically significant.

Based on results of this study, Gillanders and his colleagues are planning a larger clinical trial to test the vaccine in newly diagnosed breast cancer patients, who, in theory, should have more robust immune systems than patients who already have undergone extensive cancer therapy.

“If we give the vaccine to patients at the beginning of treatment, the immune systems should not be compromised like in patients with metastatic disease,” Gillanders said. “We also will be able to do more informative immune monitoring than we did in this preliminary trial. Now that we have good evidence that the vaccine is safe, we think testing it in newly diagnosed patients will give us a better idea of the effectiveness of the therapy.”



This work was supported by the Breast Cancer Research Program (BCRP) of the Department of Defense Congressionally Directed Medical Research Programs (DOD/CDMRP), grant number W81XWH-61-0677; Gateway for Cancer Research, P-06-016; The Foundation for Barnes-Jewish Hospital; the National Cancer Institute (NCI) of the National Institutes of Health (NIH), T32 CA009621; the NCI Cancer Center Support Grant, P30 CA91842; and George and Diana Holway.

Tiriveedhi V, Tucker N, Herndon J, Li L, Sturmoski M, Ellis M, Ma C, Naughton M, Lockhart AC, Gao F, Fleming T, Goedegebuure P, Mohanakumar T, Gillanders WE. Safety and preliminary evidence of biological efficacy of a mammaglobin-A DNA vaccine in patients with stable metastatic breast cancer. Clinical Cancer Research. Dec. 1, 2014.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.


By Julia Evangelou Strait [en línea] St Louis, MO (USA):, 29 de diciembre de 2014 [ref. 01 de diciembre de 2014] Disponible en Internet:

Typhoid gene unravelled

20 11 2014

People who carry a particular type of gene have natural resistance against typhoid fever according to new research published in Nature Genetics.

Lead researcher, Dr Sarah Dunstan from the Nossal Institute of Global Health at the University of Melbourne said the study is the first large-scale, unbiased search for human genes that affect a person’s risk of typhoid.

Typhoid is a health burden to lower income countries-

Enteric fever, or typhoid fever as it more commonly known, is a considerable health burden to lower-income countries.

This finding is important because this natural resistance represents one of the largest human gene effects on an infectious disease.

“We screened the human genome to look for genes associated with susceptibility to, or resistance from typhoid.,” Dr Dunstan said.

“We found that carrying a particular form of the HLA-DRB1 gene provides natural resistance against typhoid fever.  This gene codes for a receptor that is important in the immune response, by recognising proteins from invading bacteria.”

Typhoid is contracted, by consuming food or water contaminated with the bacteria, Salmonella Typhi or Paratyphi. It has been estimated that typhoid causes 200,000 deaths a year globally, and infects 26.9 million people per year.

“If we can understand this natural mechanism of disease resistance, then we can use this knowledge to help develop improved vaccines for typhoid fever, but also potentially for other invasive bacterial disease,”

Better treatments and vaccines are needed for typhoid fever as the infecting bacteria are getting increasingly more resistant to antibiotic treatment, and the current vaccine is only moderately effective and does not protect against paratyphoid fever, which is increasing within Asia.

This work was conducted in patients from Vietnam with findings then replicated in independent patient cohorts from Vietnam and Nepal

The research collaboration was between the Genome Institute of Singapore and Oxford University Clinical Research Units in Vietnam and Nepal. [en línea] Melbourne (AUS):, 20 de noviembre de 2014 [ref. 10 de noviembre de 2014] Disponible en Internet:

Why live vaccines may be most effective for preventing Salmonella infections

9 10 2014

Vaccines against Salmonella that use a live, but weakened, form of the bacteria are more effective than those that use only dead fragments because of the particular way in which they stimulate the immune system, according to research from the University of Cambridge published today.


The BBSRC-funded researchers used a new technique that they have developed where several populations of bacteria, each of which has been individually tagged with a unique DNA sequence, are administered to the same host (in this case, a mouse). This allows the researchers to track how each bacterial population replicates and spreads between organs or is killed by the immune system. Combined with mathematical modelling, this provides a powerful tool to study infections within the host. The findings are published today in the journal PLOS Pathogens


“We effectively ‘barcode’ the bacteria so that we can see where in the body they go and how they fare against the immune system,” explains Dr Pietro Mastroeni from the Department of Veterinary Medicine at the University of Cambridge, who led the study. “This has provided us with some important insights into why some vaccines are more effective than others.”


The multidisciplinary research team led by Dr Mastroeni used the new technique to look at the effectiveness of vaccines against infection by the bacterium Salmonella enterica, which causes diseases including typhoid fever, non-typhoidal septicaemia and gastroenteritis in humans and animals world-wide. Current measures to control S. enterica infections are limited and the emergence of multi-drug resistant strains has reduced the usefulness of many antibiotics. Vaccination remains the most feasible means to counteract S. enterica infections.


There are two main classes of vaccine: live attenuated vaccines and non-living vaccines. Live attenuated vaccines use a weakened form of the bacteria or virus to stimulate an immune response – however, there are some concerns that the weakened pathogen may become more virulent when used in patients with compromised immune systems, for example people infected with HIV, malaria or TB. Non-living vaccines, on the other hand, are safer as they usually use inactive bacteria or viruses, or their fragments – but these vaccines are often less effective. Both vaccines work by stimulating the immune system to recognise a particular bacterium or virus and initiate the fight back in the event of future infection.


Using their new technique, Dr Mastroeni and colleagues showed that live Salmonella vaccines enhance the ability of the immune system to prevent the bacteria from replicating and spreading to other organs. They can also prevent the spread of the bacteria into the bloodstream, which causes a condition known as bacteraemia, a major killer of children in Africa.


They also found that the antibody response induced by live vaccines enhances the ability of immune cells known as phagocytes to kill bacteria in the very early stages of infection, but that a further type of immune cell known as the T-cell – again stimulated by the live vaccine – is subsequently necessary for control and clearance of the bacteria from the blood and tissues. The killed vaccine, whilst able to boost the phagocyte response via the production of antibodies, did not stimulate a protective form of T-cell immunity and was unable to prevent the subsequent bacterial growth in infected organs or the development of bacteraemia, and was unable to control the spread of the bacteria in the body.


Dr Chris Coward, first author on the study, says: “We have used a collaboration between experimental science and mathematical modelling to examine how vaccines help the immune system control infection. We found that, for Salmonella infections, the immune response induced by a killed vaccine initially kills a proportion of the invading bacteria but the surviving bacteria then replicate resulting in disease. The live vaccine appears superior because it induces a response that both kills the bacteria and restrains their growth, leading to elimination of the infection.”


Dr Mastroeni adds: “There is a big push towards the use of non-living vaccines, which are safer, particularly in people with compromised immune systems – and many of the infections such as Salmonella are more prevalent and dangerous in countries blighted by diseases such as HIV, malaria and TB. But our research shows that non-living vaccines against Salmonella may be of limited use only and are not as effective as live vaccines. Therefore more efforts are needed to improve the formulation and delivery of non-living vaccines if these are to be broadly and effectively used to combat systemic bacterial infections. We have used Salmonella infections as a model, but our research approaches can be extended to many pathogens of humans and domestic animals.”


The research was carried out Dr Mastroeni, Dr Coward and colleagues Dr Andrew Grant, Dr Oliver Restif, Dr Richard Dybowski and Professor Duncan Maskell. It was funded by the Biotechnology and Biological Sciences Research Council, which has recently awarded Dr Mastroeni funding  to extend this research to the study of how antibiotics work. The new research aims to optimise treatments and reduce the appearance of antibiotic resistance.


Professor Melanie Welham, BBSRC’s Science Director, said: “To protect our health and the health of animals we rely on, such as livestock, effective vaccines are needed against disease. This new technique provides unique insights that will help us compare vaccines produced in different ways to ensure the best disease prevention strategies.”



Coward, C et al. The Effects of Vaccination and Immunity on Bacterial Infection Dynamics In Vivo. PLOS Pathogens; 18 Sept 2014 [en línea] Cambridge (UK):, 09 de octubre de 2014 [ref. 18 de septiembre de 2014] Disponible en Internet:

La Fe trata las alergias con vacunas personalizadas más efectivas

2 06 2014

Las técnicas de análisis de biología molecular facilitan la elaboración de vacunas personalizadas que han beneficiado ya a 800 pacientes

  • El Hospital Universitari i Politècnic La Fe ha acogido un curso de “Diagnóstico Molecular en el Paciente Polínico”
  • 1 de cada 4 españoles sufre algún tipo de alergia, según la Sociedad Española de Alergología e Inmunología Clínica.


El Hospital Universitari i Politècnic La Fe mejora el diagnóstico de las alergias con nuevas técnicas de biología molecular más eficaces que permiten la elaboración de vacunas personalizadas para el paciente.

El análisis de la alergia a nivel molecular se introdujo como técnica en el Hospital Universitari i Politècnic La Fe en 2009, después de que investigadores del Instituto de Investigación Sanitaria La Fe (IIS La Fe) la testaran en pacientes con anafilaxia alimentaria y propusieran extenderla a las alergias respiratorias.

Hasta el momento más de 800 pacientes se han beneficiado de esta nueva técnica.


Combinar las clásicas pruebas cutáneas de detección de alergias con el análisis molecular, sin olvidar la historia clínica del paciente, permite determinar con más exactitud la causa de la enfermedad alérgica. “Las pruebas cutáneas identifican el agente causante, y la biología molecular, las proteínas exactas de ese agente que desencadenan la reacción alérgica” ha explicado la Doctora Hernández Fernández de Rojas.

Esta precisión diagnóstica, ha añadido el Doctor Ramón López Salgueiro, investigador del IIS La Fe en el Servicio de Alergia de La Fe, permite desarrollar vacunas (en el caso de las alergias respiratorias) que inciden específicamente en la sensibilización de cada paciente, aumentando la eficacia terapéutica y la adhesión al tratamiento.

“Hay estudios que demuestran que el diagnóstico molecular modifica la composición del extracto alergénico seleccionado para la vacuna a partir de las pruebas cutáneas en un 55% de pacientes”, advierte el Doctor López Salgueiro, por lo que insiste en la efectividad de la técnica.


El análisis de la alergia a nivel molecular se hace a partir de una muestra de sangre y se puede realizar molécula a molécula o mediante microarrays que, por nanotecnología, se consigue identificar hasta 112 componentes potencialmente alergénicos en una sola gota de sangre.

Estas técnicas de biología molecular se aplican a la Alergología también en la Clínica Universidad de Navarra y en el Hospital Universitari Vall D’Hebrón de Barcelona.



Curso de Diagnostico Molecular en el paciente Policlínico

El Hospital ha acogido un curso de “Diagnóstico Molecular en el Paciente Polínico” dirigido a especialistas, centrado en la Salsolakali (planta característica de las dunas de playa) y coorganizado por la Doctora Dolores Hernández Fernández de Rojas, responsable del Grupo Acreditado del IIS La Fe en Alergia y Enfermedades Respiratorias, y jefe del Servicio de Alergología del Hospital La Fe.

Actualmente, uno de cada cuatro españoles sufre algún tipo de alergia, según el último estudio Alergológica de la Sociedad Española de Alergología e Inmunología Clínica(SEAIC). [en línea] Valencia (ESP):, 02 de junio de 2014 [ref. 22 de mayo de 2014] Disponible en Internet:

Un pediatra catalán, entre los diez jóvenes más sobresalientes del mundo 2012

12 11 2012

Barcelona, 30 oct (EFE).- El pediatra catalán Quique Bassat ha sido escogido como uno de los diez jóvenes más sobresalientes del mundo este año por la Joven Cámara Internacional en la categoría de innovación médica por su “extraordinario trabajo en pediatría y en investigación médica en los países en desarrollo”.


Un pediatra catalán, entre los diez jóvenes más sobresalientes del mundo 2012

Un pediatra catalán, entre los diez jóvenes más sobresalientes del mundo 2012

Barcelona, 30 oct (EFE).- El pediatra catalán Quique Bassat ha sido escogido como uno de los diez jóvenes más sobresalientes del mundo este año por la Joven Cámara Internacional en la categoría de innovación médica por su “extraordinario trabajo en pediatría y en investigación médica en los países en desarrollo”.

La Joven Cámara Internacional (JCI) es una organización internacional fundada en 1944 que participa en el sistema de las Naciones Unidas (ONU) y cada año selecciona a los jóvenes que más han destacado en el campo de la innovación e investigación para mejorar la calidad de vida de las personas.

Quique Bassat, que ha destacado por sus trabajos contra la malaria, recogerá su distinción el próximo 20 de noviembre en el Congreso Mundial de la JCI, que este año se celebrará en Taipei (Taiwán).

“Es muy importante que la JCI se fije en el trabajo que se hace en torno a las enfermedades olvidadas, especialmente en el campo de la malaria, ya que supone un empujón a la investigación médica en los países donde más se necesita”, ha declarado Quique Bassat al conocer la noticia.

“Además, este premio supone un reconocimiento a la investigación como motor de la innovación y del desarrollo de los países pobres”.

Doctor en medicina por la Universidad de Barcelona, Quique Bassat es un médico pediatra especializado en medicina tropical y en epidemiología.

Posee una amplia experiencia en la realización de ensayos clínicos en países en vías de desarrollo, entre los que se encuentra los ensayos de la primera vacuna candidata contra la malaria, la RTS,S.

En la actualidad trabaja como investigador en el CRESIB, el centro de investigación del Instituto de Salud Global de Barcelona (ISGlobal), donde coordina la implementación de varios proyectos relacionados con la malaria en países como Mozambique, Brasil, India o Papúa Nueva Guinea.

La JCI premia cada año a diez jóvenes menores de 40 años que, a través de su trabajo y de la innovación, desarrollan cambios positivos que contribuyen a crear un mundo mejor.

Además del doctor Bassat, entre los diez premiados en 2012 se encuentran los filipinos Benigno “Bam” Aquino y Maurice Edsel Salvana, premiados por su trabajo en microfinanzas y en VIH/SIDA respectivamente; el abogado inglés Bobby Kensah por su trabajo social con jóvenes pandilleros en Inglaterra; Fela Mijoro Razafinjato de las islas Maldivas por su trabajo con las personas con discapacidad y la líder ambiental Keneilwe Mosekis de Botswana, entre otros. [en línea] Madrid (ESP):, 12 de noviembre de 2012 [ref. 30 de octubre de 2012] Disponible en Internet:

Se confirma la eficacia de la vacuna contra el VPH también en mujeres adultas

2 06 2011

La vacuna contra las variantes 6, 11, 16 y 18 del virus del papiloma humano (VPH) también es segura y eficaz en mujeres entre 24 y 45 años. Así lo concluye un estudio internacional realizado a cerca de 4.000 mujeres que se publica en British Journal of Cancer.

Hasta ahora existían muchos estudios que confirmaban la eficacia de la vacuna en chicas de 14 a 26 años. Éste es el primer estudio que lo demuestra en mujeres mayores de 26 años.

En el estudio, encabezado por Xavier Castellsagué, investigador de la Unidad de Infecciones y Cáncer del ICO-IDIBELL, han participado 3819 mujeres sanas con edades comprendidas entre los 24 y 45 años. La mitad recibieron la vacuna y la otra mitad un placebo. A partir de aquí, se les realizó un seguimiento en el que se monitorizó la cantidad de anticuerpos desarrollados, las infecciones por VPH, las lesiones preneoplásicas y las verrugas genitales durante los 4 años posteriores. Los datos del estudio confirman no sólo la seguridad de la vacuna, sino también su elevada eficacia en la prevención de estas infecciones y lesiones vinculadas al VPH.

El virus y las vacunas

El virus del papiloma humano es el responsable de todos los tumores de cuello de útero y de las verrugas genitales. Este tumor es la segunda causa de muerte por cáncer en las mujeres, por detrás del de mama. Cada año se diagnostican 500.000 casos en todo el mundo, la mitad de los cuales fallecen por dicha causa. En España, se producen alrededor de 2.100 casos de cáncer y unas 700 muertes al año.

En los últimos años se han producido importantes avances en el desarrollo de vacunas preventivas. El Instituto Catalán de Oncología ha sido el único centro español que ha participado en los ensayos clínicos de las dos vacunas existentes hasta el momento: una tetravalente, contra las variantes 6 / 11 / 16 y 18 del virus, y una bivalente, contra las variantes 16 y 18. Alrededor del 70% de todos los tumores de cérvix son causados per estos dos subtipos de VPH.

Actualmente, ya se están desarrollando nuevas generaciones de vacunas que protegen contra un abanico más amplio de virus.

Butlletí digital de l’Institut Català d’Oncologia [en línea] Barcelona (España):, 02 de junio de 2011, [ref. 02 junio de 2011] Disponible en Internet: