With this video we are launching a new themed channel, Your Pharmacist Informs, focused on the world of vaccines. This is a monthly initiative to publish video-advice on different topics related to vaccination.

The purpose of this video-advice channel is to provide robust, quality health information, backed by professional pharmacists. Consequently, you can educate people, especially given misinformation circulates on the Internet and in social networks.

Vaccines are drugs that generate an immune response to the causative agent of an infectious disease (virus or bacteria), so that the immune system reacts quickly and powerfully to prevent the disease in the event of subsequent contact with the microorganism.

There is currently a wide variety of types of vaccines, with different compositions.

Generally speaking, it can be said that a vaccine always contains an antigen of the microorganism or, in the case of messenger RNA vaccines, the instructions for our cells to produce that antigen. The antigen is the active ingredient of the vaccine, i.e. the compound that is recognized by the immune system and triggers a response.

This antigen can be presented in different forms depending on the method of vaccine manufacturing. Thus, a distinction is made between:

o live attenuated vaccines, which will include whole microorganisms deprived of their ability to cause disease
o inactivated vaccines, with whole killed or inactivated microorganisms;
o toxoid vaccines, which are inactivated toxins;
o capsular polysaccharide vaccines, whose antigen is the sugar present in the capsule of a bacterial species;
o recombinant protein vaccines produced by genetic engineering;
o and the messenger RNA vaccines.

However, the major component of vaccines, especially those administered by intramuscular injection, which are the most common, is water. Thus, high quality sterile water is usually used for injectable preparations.

In addition, it is important to ensure that the quality of the preparation is maintained over time and to avoid contamination. For this reason, vaccines also usually contain a preservative. The most used preservative for years has been 2-phenoxyethanol, which is considered very safe due to its low toxicity.

Stabilizers can also be used in the manufacture of a vaccine. They prevent reactions from occurring in the drug that could degrade the active ingredient or reduce its efficacy. Some of the most used are sugars such as sucrose and some proteins or amino acids.

In vaccines it is also possible to find surfactants, which favor an adequate mixture of all the components.

And although not in all vaccines, some vaccines use adjuvants, which are substances that contribute to improve the immune response produced by the vaccine. The most used are some aluminum salts (such as aluminum phosphate or aluminum hydroxide), whose safety has been widely proven.

Remember, always ask your trusted pharmacist. We will help you and answer any questions you may have about vaccines and their composition.


Referencias

1. ¿Cómo se desarrollan las vacunas? [Internet]. Organización Mundial de la Salud [Acceso septiembre 2023]. Disponible en: https://www.who.int/es/emergencies/diseases/novel-coronavirus-2019/covid-19-vaccines/how-are-vaccines-developed.

2. Dévora Figueroa C, Díaz García Ó, Díez González LM, Fernández del Pozo de Salamanca MB. Fundamentos de la vacunación. En: Vacunación frente a rotavirus. Consejo General de Colegios Oficiales de Farmacéuticos. 2019