Duration of effect of a flu vaccination
After an influenza vaccination, the immune system forms antibodies against the specific strain of influenza virus that was included in the vaccination. In principle, these antibodies remain in the body for years, but their number decreases over time. Nevertheless, the body is usually immune to the specific influenza strains for several years.
However, since the flu virus is constantly changing, the vaccination must be repeated every year. However, one is vaccinated against the new flu strains. The time until one is immune against the flu virus after the vaccination is usually a few days. The immune system needs this time to form the first effective antibodies against the flu viruses.
Pathogen
Influenza, also called influenza, is transmitted by the influenza viruses. They can be divided into A, B and C types. For humans, however, only types A and B are relevant in case of illness.
The most important characteristic of these viruses is their surface structure. The characteristic structures for these viruses are the so-called haemagglutinin (HA abbreviated) and neuraminidase (NA abbreviated). Haemagglutinin and neuraminidase are specific protein molecules that are located on the surface of the viruses.
The interesting or rather the complicated thing about these structures is that these two proteins still have a number of subgroups. It is precisely these subgroups that make the development of a vaccine considerably more difficult. Due to a multitude of different mechanisms, the composition of the surface structures is constantly changing. However, since the antibodies that the human body forms are only ever directed against very specific structures, a single vaccination with the influenza vaccine cannot prevent every subgroup of influenza viruses.Therefore, the flu vaccine is adapted each year to the current composition of the subgroups of influenza viruses.
What is the difference between the triple and quadruple vaccination?
Influenza viruses can be divided into different strains of bacteria. These are divided into A and B strains. Often the A strains of the flu are predominant, therefore a so-called trivalent vaccine (triple vaccine) exists, which is supposed to work against the two most important representatives of the A flu as well as a B flu virus strain.
The tetravalent vaccine (quadruple vaccine), on the other hand, contains an additional component that is intended to help against another B strain. Therefore, this vaccine is of particular importance in a season in which the B flu is also widespread. As a rule, however, it is difficult to predict which influenza viruses will circulate more frequently.
The influenza strains that were addressed in the trivalent vaccine 2017/2018 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2) and B/Brisbane/60/2008 or strains closely related to the three mentioned. For the tetravalent vaccine, B/Phuket/3073/2013 (or similar strains) is also covered. As a rule, the triple vaccine is less expensive, which is why health insurance companies conclude discount contracts mainly for this.
The quadruple vaccine, on the other hand, is often not covered by health insurance companies. Whether the triple or the quadruple vaccination is more sensible cannot usually be determined before the flu season. It depends very much on which flu strains are in circulation the most.
For normally healthy people, the trivalent vaccine is usually sufficient. This covers the flu strains that are most likely to dominate the flu season. Who would like to go on the safe side can also decide for the trivalent vaccine, however one must pay for it in many cases the vaccine itself and should contact therefore before the inoculation its health insurance company.
