Do you remember having chickenpox? Herpes zoster (HZ), popularly known as shingles, is a rash that is caused by the reactivation of the chickenpox virus.
After passing this disease, the pathogen remains inactive in the nervous tissue, but, over the years, it can reactivate and give rise to herpes zoster . In addition, the appearance of HZ can cause postherpetic neuralgia, a chronic neuropathic pain that inflames the nerves and that does not go away with the usual painkillers. Although this is the most common complication, HZ also causes skin infections or muscle paralysis.
Regarding prevention, in 2006 the first vaccine to deal with this infection , Zostavax, was approved, to which Shingrix joined in 2017. The first is made from the attenuated virus and is administered in a single dose, while the second is made from a protein present on the surface of the viral agent and requires two pricks.
The main difference between the two is the degree of immunization they generate: Zostavax reaches around 60% -70%, and Shingrix, around 90%. This greater efficiency has opened up new possibilities in the approach to HZ, an idea in which Javier Díez Domingo, head of the Vaccine Research Department of the Foundation for the Promotion of Health and Biomedical Research of the Valencian Community (Fisabio), and Javier López Jiménez, head of the Hematology and Hemotherapy Service at Hospital Ramón y Cajal, in Madrid.
After the administration of the vaccine, patients may feel discomfort in the area where it has been injected or even a low-grade fever. However, and according to specialists, these adverse effects cannot be compared to those caused by herpes zoster.
In this sense, Shingrix has meant “a before and after in the quality of life of patients,” says Dr. Díez Domingo, who has participated in the research studies of the vaccine. This expert points out that approximately half of the people who reach the age of eighty will have suffered an HZ infection. It is estimated that 200,000 cases occur annually in Spain, especially in people over fifty years of age and people with a weakened immune system.
Precisely, according to Dr. Díez Domingo, “immunosuppressed people have a higher incidence of HZ, because the lowering of their defenses facilitates the reactivation of the virus.” For this reason, access to an effective vaccine is of special relevance to them.
Despite the fact that immunization is indicated for those over fifty years of age – the age at which the incidence begins to increase – the decision of who should be vaccinated corresponds to the health authorities. And taking into account that immunocompromised people are those who express the greatest urgency to receive the drug, the Public Health Commission, in which all the autonomous communities and the Ministry of Health are represented, has recently approved the recommendation to click patients with hematopoietic stem cell transplantation –immature cells that produce blood– and solid organ transplantation , people infected with HIV and those who receive certain treatments for rheumatological and non-rheumatological diseases and who are in a situation of greater immunosuppression.
In this sense, Dr. López Jiménez explains that being able to count on the Shingrix vaccine for patients who have received transplants of hematopoietic progenitors is very important, since the incidence of herpes zoster in this type of patients is approximately ten times higher than that of the general population . In fact, specialists systematically provide them with antivirals to prevent the appearance of HZ; the moment its administration is stopped, the risk of the painful rash appears.
The expert also indicates that in these patients a high incidence of neuralgia due to herpes zoster is observed, which “may have significant complications.” On the other hand, Dr. Díez Domingo points out that it would be convenient to start vaccinating a healthy population over 65 years of age.
In conclusion, vaccination against herpes zoster should be a priority in adults suffering from immunity problems and, over time, it should be administered to the entire healthy population from 60-65 years of age. This is advised by the Fisabio expert, who highlights the need to have enough vaccines available to carry out this type of public health action, as well as to have the corresponding budget.
Maximum efficiency
“With the new inactivated vaccine we achieve greater immunization power and that the response lasts longer,” says Dr. López Jiménez on the effectiveness of Shingrix. In general terms, the drug achieves up to a 90% immune response in patients over fifty years of age , but, in addition, the expert highlights the durability of the antibodies in the medium and long term.
This greater immunity is also reflected in the more immunocompromised population. For example, in patients with autologous hematopoietic stem cell transplantation, the immune response is around 70%, while in people with hematological neoplasms it is 80% -85%.
In addition to achieving a longer period of immunity in these patients, Dr. López Jiménez explained that vaccination against herpes zoster “does not interfere with the antineoplastic treatment followed by these patients, which should not be delayed or paralyzed.”
This fact would also contribute to the vaccine being well accepted by patients.
