Vaccination with various active ingredients: “Doctors are worried that the side effects could be too high”

In autumn, vaccination can be carried out after vaccination: Immunization against herpes zoster is now also recommended for risk groups under 50 years of age. In addition, many people need protection against flu and corona due to the season. This begs the question: What are you actually asking the immune system to do? Can the body handle it?

Is there a maximum number of simultaneous vaccinations?

The Standing Commission on Vaccination (Stiko), which develops scientific recommendations for vaccination in Germany, does not specify how many vaccinations can be given at once. Those affected should make such decisions with their doctors, according to the Robert Koch Institute (RKI), where Stiko is headquartered.

Some family doctors may be hesitant to give multiple vaccinations at once, said Dortmund immunologist Carsten Watzl. “Not because they don’t know Stiko’s recommendations, but because they are afraid that the vaccination reaction could be too high if several vaccinations are given at the same time.” In addition, if serious reactions or side effects do occur, it is easier to prescribe specific medications.

Is there a specific waiting time between vaccinations?

According to Stiko, several live vaccines can often be given at once. This drug consists of weakened and reproducible viruses or bacteria and is used against measles, mumps, rubella, or chicken pox.

However, if live vaccines are not administered at the same time, at least four weeks must elapse as typical reactions such as pain at the injection site may occur over a period of time.

According to Stiko, in many cases it is not necessary to maintain a time gap between several inactivated vaccines or between inactivated and live vaccines. Preparations with dead pathogens that are no longer capable of reproduction are used against shingles, hepatitis B, diphtheria or tetanus, as well as in most flu vaccines.

The gene-based product, which rose to fame with its mRNA shots against the coronavirus, can also be classified as an inactivated vaccine because it does not contain any pathogen that can reproduce.

Flu and corona vaccination at the same time?

These two immunizations can be given simultaneously. “Both work just as well as if you managed them,” Watzl said. As recommended by Stiko, sutures should be placed on different parts of the body – for example on different upper arms. According to Stiko, so far no serious intolerance has been described as a result of administering the mRNA vaccine to the Covid and influenza vaccines simultaneously.

Is a combination vaccine better?

This preparation is as safe as a single dose, but has the advantage of reducing the number of injections required. So you are protected from several diseases at once with just one bite. This means: fewer doctor visits, less stress, and less risk of unwanted reactions such as pain at the injection site. Stiko even recommends using a combination product.

There are six types of vaccines that are effective against diphtheria, tetanus, polio, Haemophilus influenzae type b (Hib), whooping cough and hepatitis B, or four types of vaccines for measles, mumps, rubella and chicken pox. According to the Federal Institute for Public Health, the active ingredients are coordinated in such a way that they do not overload the immune system – even in infants and young children.

“If I received six times the vaccine, I would not get a six times stronger vaccination reaction,” Watzl assured, but only to the same extent as the component with the strongest reaction.

What is recommended for children?

It is true that today’s children are immunized against more diseases than ever before. However, fewer pathogenic components that trigger an immune response in the body are transmitted than at that time. Current preparations are very pure and usually contain only certain parts of the pathogen.

“Certain infections can cause much more severe disease in babies and young children than in older children, for example because babies’ airways are still very narrow or because their still-developing immune systems cannot fight certain infections effectively,” wrote the RKI. “Vaccination at the recommended vaccination times will protect infants and young children from infection and potentially serious consequences.” They are also tolerated in infancy.

So there’s no concern about multiple vaccinations?

Yes, said RKI. The body is not overwhelmed by parallel administration. “The immune system is so strong that it can react to a large number of vaccines at the same time,” said RKI. A harmless or partial version of the pathogen is injected into the body via a syringe. The body then produces antibodies and memory cells that can react immediately upon contact with the actual pathogen.

What exceptions are there?

Currently, for the live vaccine Ixchiq (Valneva), approved in Germany against chikungunya fever, which is transmitted by mosquitoes, simultaneous immunization against other diseases is not recommended due to lack of data. Such information can be found in the specialist information or package inserts for each product.

However, in tropical medicine, repeated administration is commonplace, simply because those affected are under a certain amount of time pressure before a planned long-distance journey. Watzl: “Travel doctors know how to give multiple vaccinations at once.”