Booster vaccination – 5 reasons for the booster

Experts from Sweden examined the effectiveness of the  corona vaccines  over a longer period of time. The results of the unpublished study are already available as a preprint in the specialist journal “The Lancet”. But other analyzes also show a decreasing vaccination protection.

While the effectiveness of the Corona vaccines from BioNTech/Pfizer is 92 percent two weeks to one month after vaccination, the vaccine only achieves an effectiveness of 47 percent 121 to 180 days after vaccination. After 211 days, i.e. after about seven months, the vaccine should no longer reliably protect against symptomatic infections, and the risk of a severe course can also increase again.

Moderna ‘s  mRNA vaccine is said  to   still protect up to 59 percent against symptomatic disease after six months. AstraZenca’s vector vaccine, on the other hand, loses its effectiveness much faster – population data shows that as little as 121 days after immunization there may be no effect against symptomatic infections. With a heterologous vaccination, i.e. a mix of mRNA and vector vaccine, the effectiveness also slowly decreased – however, the vaccine combination still protects against a course with symptoms even after four months.

A booster vaccination increases the effectiveness of the vaccination. Experts assume that this will persist for a longer period of time. After the third vaccination dose, the antibody level increases much more than after the primary immunization. There is also an increase in B and T cells, which recognize the virus’s spike protein and destroy already infected cells to prevent infection in the body.

2. Less effective against virus variants

The virus variants are still on the rise – after the dominant alpha variant was replaced by the currently dominant delta variant, another dangerous mutation is already on the rise with the omicron variant.

Due to their structural changes, the variants are more infectious and therefore pose a higher risk. They can also trick the antibodies and thus evade the immune response. In order to reduce the risk of vaccination breakthroughs and to prevent the rapid spread of the virus variants, a vaccination booster can also be very useful.

3. Strong protection against severe gradients

Initial data from Israel shows that people who have already received a booster vaccination have a lower risk of developing a severe course. This is particularly evident when compared to the unvaccinated. The number of  corona patients per 100,000 inhabitants who  had to be treated in the hospital differed significantly in Israel:

• Unvaccinated: 6.4
• Basic immunization: 1.62
• Booster vaccination: 0.28

In order to protect high-risk patients from a severe course and not to strain the capacities of the health system, booster vaccinations are recommended in addition to basic immunization.

4. Lower risk of infection

In addition to severe courses, the booster vaccination can also reduce the risk of infection. The path of the viruses into the human body usually starts via the mucous membrane cells in the nose and throat – these mucous membranes, however, have their own  immune system : the IgA antibodies of the mucous membranes react immediately to the entry of the viruses, fight  SARS-CoV-2  and can completely prevent infection.

Since the IgA antibodies usually decrease more quickly after the primary immunization, a third vaccination is necessary to maintain protection. As with other vaccinations, the corona vaccination is particularly effective 14 days after the booster.

5. Booster vaccination stops further corona waves

In order to prevent vaccination breakthroughs and the rapid spread of the Delta variant or other virus variants, Israel started the third vaccination in risk patients and people over 60 years of age as early as the summer. People under the age of 60 followed in early autumn – at the same time there was  progress in vaccination  in the 12 to 18 age group. The result: the overload of the health system, high incidences and a fourth wave could be greatly reduced.

Both an increase in fully vaccinated people and the number of booster vaccinations can help contain the  pandemic  and prevent further waves. In order to further accelerate vaccination progress in Germany, some vaccination centers have reopened, local vaccination campaigns are offered and general practitioners continue to vaccinate against SARS-CoV-2.