The vaccine is a preparation of antigens to promote the formation of antibodies and generate an immune response.
Vaccine is a term with different uses and applications. On the one hand, it refers to anything belonging to or related to bovine cattle , that is, to cows . For example: "This jacket has been made with the best cowhide" , "The agricultural activity suffers from the fall in the price of cattle, which has reached its lowest level in fifteen years" .
On the other hand, a vaccine is an organic principle or a virus that, prepared in a certain way, is inoculated into a person or animal to protect it against a specific disease .
The vaccine in medicine
A vaccine is a preparation of antigens , which is a substance that allows the formation of antibodies and has the capacity to generate an immune response within the body. This attack response allows the development of an immunological memory that generally produces permanent immunity against the disease.
Every human being needs certain vaccines to avoid being infected with diseases or pathologies of various kinds; however, the people who require them the most are newborns. Thus, it is common that in the first months of life they have to undergo vaccine injections to avoid being infected with measles , meningitis , mumps or poliomyelitis , among other problems.
The COVID-19 vaccine was key to reducing the effects of the pandemic .
Requirement for travel
It should also be noted that, on many occasions, when travelling to certain areas of the globe, it is necessary to undergo certain vaccinations to avoid being infected with diseases that are common in those places.
For example, any Spanish citizen who decides to travel to South Africa will need to be vaccinated against yellow fever and malaria. Whereas if the destination is Thailand , where the traveller will be practising sport or temporarily residing in rural areas, it is recommended that travellers be vaccinated against malaria and also receive the anti-tetanus and anti-rabies vaccines.
Historical development of vaccines
The first vaccine in history would have been the one created by the English country doctor Edward Jenner in 1796 , who discovered that cowpox immunized people from suffering from human smallpox , which was much more serious and deadly.
Over time, various vaccines emerged to counteract diseases such as rabies (1882), plague (1897), tuberculosis (1927), yellow fever (1935), influenza (1945), measles (1964), rubella (1970), chickenpox ( 1974), meningitis (1978) and hepatitis A (1992), among many others.
All this without overlooking that among the most recent vaccines, those of the 21st century , there is the human papillomavirus vaccine that appeared in 2005; a first vaccine to end cocaine and heroin addiction that was released in 2008; in 2009 the first vaccine against the famous flu A appeared; and more recently, the vaccine against COVID-19 .
A distinction can be made between the inactivated virus vaccine (made up of harmful microorganisms that, when treated with chemicals or heat, lose their ability to cause damage), the attenuated live virus vaccine (with microorganisms grown under conditions that make them lose their harmful properties), the toxoid vaccine (which has inactivated toxic components from microorganisms) and the subunit vaccine (includes fragments of microorganisms), among others.
The effectiveness of the vaccine depends on each case.
Other considerations
It is important to note that immunization can have different characteristics. Acquired immunity occurs when the immune system reacts to the presence of a foreign substance. If the subject receives the antibodies directly (through breast milk, for example), we speak of passive immunity ; on the other hand, active immunity is developed by the body after exposure to the substance or microorganism. A vaccine, therefore, promotes active immunity.
The vaccination schedule is the scheme planned by the State to take care of public health through mass vaccination of the population. Sometimes, booster doses may be included to improve the effectiveness of the vaccine: therefore, a distinction can be made between a single-dose vaccine and a multi-dose vaccine .
This vaccination scheme promoted by governments refers to compulsory vaccination . Vaccines such as COVID-19, on the other hand, are part of voluntary vaccination campaigns .
It is always important to consider the contraindications of the vaccine . Health authorities usually carry out extensive research to determine whether there may be an adverse reaction to the vaccine and which population groups are most susceptible to them.
Regardless of this issue, certain precautions must be taken with all vaccines to protect the health of citizens. One of them is the care of the cold chain when refrigeration of vaccines is essential.