Before proceeding with the vaccination, several important questions must be answered, writes the German public broadcaster ARD in an extensive publication on the subject.
Why is there a new flu vaccine every year?
Flu viruses are constantly changing – to overcome the immune system. Even in healthy people who have built up a strong immunity against different flu viruses thanks to multiple infections and vaccinations, new viruses can bypass the immune system and cause infection. The already created immunity does not always succeed in preventing the infection, but it protects us from a severe course of the disease.
About two-thirds of flu infections pass mildly or even without symptoms, but in one-third of cases it is true flu with severe symptoms. This can be dangerous and even deadly, especially for older people or people with pre-existing medical conditions. Therefore, the immunization of these groups of people is particularly important and recommended, explains ARD.
How is it decided which variants to immunize against?
Laboratories around the world are constantly researching which groups of viruses are currently circulating and trying to gauge which variants are the most aggressive. The data is then sent to the World Health Organization.
From there, in February, it comes out with a forecast of which four virus strains are likely to dominate the Northern Hemisphere during the next flu season. Thus, vaccine manufacturers have time to adapt their preparations.
As a rule, they have already received approval and no further in-depth research is required. However, the safety and effectiveness of vaccines are constantly being studied -- even after approval.
Who is recommended to be vaccinated?
In Germany, the Vaccination Commission recommends that the risk groups be immunized this year as well. These are people over 60, pregnant women and people with certain underlying diseases, as well as those who – official or private – have many contacts with such high-risk patients. In addition, people who are at increased risk of infections should be vaccinated – for example if they come into contact with many people at their workplace.
The fact that no special recommendation was made to the others does not mean that the commission would like to prevent them from getting immunized. In healthy children, young people and adults, the infection is usually so mild that there is no risk of serious illness. Therefore, there are no recommendations for them, but nevertheless they can be immunized and thus reduce the probability of becoming infected, as well as infecting others.
What proportion of Europeans are vaccinated?
In Germany, the proportion of people who get vaccinated against the flu is relatively low. During the pandemic, the numbers increased, but then decreased again. In almost all the age groups studied, the proportion of the vaccinated is on average below 50 percent.
For people over 65, the EU has recommended 75 percent vaccination. According to Eurostat data, Germany is 43 percent far from this goal – only Denmark, Portugal and Ireland achieve the target quota.
How effective are vaccines?
Because viruses and vaccines are constantly changing, the effectiveness of immunizations can be very difficult to determine. It is based mainly on how good the WHO prognosis is, but also on individual factors. For example, in older people, the effect of vaccines is weaker – therefore, it is advisable to give them higher doses.
According to data from the "Robert Koch" between 2010 and 2019, the effectiveness of flu vaccines in Germany was between 20 and 60 percent. But it should be borne in mind that immunization mitigates the course of the disease, even if it cannot prevent it.
What side effects are there?
As a rule, there are no problems with the tolerance of vaccines – there are rarely very mild side effects, such as cold-like symptoms or pain at the injection site. The flu vaccine also has good compatibility with other vaccines, for example against the coronavirus.
Most flu vaccines are produced in incubated chicken eggs. And although there should be no remains of eggs in the finished preparations, people with an allergy to egg whites should be careful and discuss the matter with their doctor.
In rare cases, severe allergic reactions may occur. There are also vaccines that are made in cell cultures. There is no risk of an allergic reaction caused by eggs.
Do vaccines continue to be improved?
For several years, vaccines have also been available in the form of a nasal spray. They are mostly recommended for children. RNA and DNA vaccines are also new – on the example of preparations for immunization against the coronavirus. They are currently under development and could be on the market in a few years.
Their decisive advantage is that they can adapt very quickly to current flu variants, and their production is easier. At the same time, scientists are trying to create a universal vaccine that would be effective against all influenza viruses and would not need to be constantly adjusted. For now, however, it is not clear whether it will become a fact at all.