That’s how effective the heterologous booster at Johnson & Johnson is
Since June, the American National Institute of Allergy and Infectious Diseases has been analyzing the effectiveness of the booster vaccination with all 9 possible combinations of the corona vaccines from BioNTech/Pfizer, Moderna  and Johnson  & Johnson approved in the USA.
Heterologous booster vaccination achieves high efficacy
A total of 50 people who had already been fully vaccinated received a booster of their previous vaccination protection. In most cases, switching vaccines resulted in a better antibody response. The antibody titer increased by a factor of 6.2 to 76. When boosted with the same vaccine, the titer increased by a factor of 4.2 to 20.
The titer is generally a measure of the number of antibodies against SARS-CoV-2  or other diseases in the blood. A blood sample  is diluted until antibodies can just be detected. The dilution level is called the titer and is used to prove the vaccination protection of a vaccination.
In particular, the heterologous vaccination scheme, i.e. the change from a vector vaccine to an mRNA vaccine , shows a significant increase in the antibody titer:
- Booster with a Moderna vaccine: Â The number of neutralizing antibodies increases from an initial 8.9 on the day of vaccination to 676.1 two weeks after the booster.
- Booster with BioNTech/Pfizer: Â The original vaccination protection rose to 341.3 from the day of vaccination two weeks later.
- Booster with Johnson & Johnson: Â The second vaccination with the vaccine from Johnson & Johnson achieved a titer of 31.42.
The higher antibody titer after the booster with Moderna could be due to a higher dose of vaccine.
Third vaccination of the mRNA vaccines effective
The vaccine combinations of the mRNA vaccines are also found to be particularly effective. Re-dosing with BioNTech/Pfizer yields an antibody level of 446. If the BioNTech vaccination is boosted with Moderna, the titer can increase up to 785. The most effective is a third vaccination with Moderna, which reaches a titer of 901.
All booster vaccinations are well tolerated, the most common side effects were pain at the injection site, as well as fatigue and headaches or muscle pain.
