It is suggested that the possibility of using different vaccines in the second booster is three different studies. These studies have verified the immune response of Pfizer BioNTech after the initial dose of AstraZeneca: “There are few side effects and strong antibody response”.
Considering that rare cases of thrombosis associated with platelet deficiency under the age of 60 may not be vaccinated with AstraZeneca, in Italy, some hypothesis Change vaccination strategy For those who have already received the first dose of Enswiss serum with the mRNA booster vaccine. Canada has decided to change the possibility of vaccination plans, and some European countries have also recommended the use of different vaccines for certain patients for a second vaccination.
Pfizer’s second dose after AstraZeneca
The first data, report one Review Published in the magazine science, It is suggested that the method can be Actually beneficialSpecifically, in three recent studies, researchers found that using Pfizer’s vaccine to vaccinate a single dose of AstraZeneca vaccine and booster “Produce a strong immune response“. Two of the studies also show that, “The response to the vaccine mixture is at least as protective as two doses of Pfizer’s BioNTech product“.
These tests only cover some of the potential combinations of Covid vaccines available today. But experts believe that if this combination proves to be safe and effective, it may accelerate the possibility of immunization to protect billions of people. “This possibility opens up new prospects for many countries“Cristóbal Belda-Iniesta, a clinical research expert at the Carlos III Health Institute in Madrid, said. For example, the government can immediately distribute new doses Don’t worry about shelving A second dose of the specific vaccine will be given a few weeks or months later.
In detail, in Belda-Iniesta’s Spanish study of 448 people who received an 8-week dose of Pfizer’s BioNTech vaccine After the first dose of AstraZeneca, Two weeks after the second injection, there were almost no side effects and strong antibody reactions. “All 129 blood samples tested can neutralize Spike protein —— The key to Sars-CoV-2 coronavirus used to bind and infect human cellsThe researchers reported in a study published in a preprint Lancet.
Similarly, Leif Erik Sander, an infectious disease expert at the Charité University Hospital in Berlin, and his colleagues observed that 61 medical staff were receiving the first dose of AstraZeneca and the second dose of Pfizer-BioNTech Antibodies are produced after an interval of 10-12 weeks.Anti-spike protein Comparable to the level found in the control group They received two doses of Pfizer BioNTech at a standard 3-week interval and showed no increase in side effects.
They are more encouraging result Regarding the cell-mediated immune response (T lymphocytes), it can increase the antibody response and help Eliminate infected cells: Analysis showed that people who received the first dose of AstraZeneca and the second dose of Pfizer BioNTech responded slightly better to Spike protein than those who were fully vaccinated with Pfizer.The third research group he led A study The smaller German Ulm achieved comparable results.Both surveys are preprinted on MedRXiv.
“There can be two different vaccines More effective than any vaccine aloneDan Baruch of the Beth Israel Deaconess Medical Center in Boston, USA, said he helped develop the single-dose vaccine produced by Johnson & Johnson. This serum, like the two doses of AstraZeneca vaccine, uses a non-replicating adenovirus as a viral vector to introduce DNA encoding the Sars-CoV-2 Spike protein into the cell. Pfizer-BioNTech and Moderna’s vaccines use messenger RNA (mRNA) encoding the Spike protein.
According to the researchers, Combination of two different vaccines It can provide a different way for the immune system to recognize pathogens. “mRNA vaccines are really good at inducing antibody responses, while carrier-based vaccines are better at triggering T cell responsesSander added.
Oxford University vaccine expert Matthew Snape agreed with the effectiveness of the combination after obtaining more data in the coming weeks, and warned that the improvement in T cell response may come from Dosage range Longer than the combination of two serums.