The CombivacS study will measure the level of antibodies produced by people receiving Pfizer vaccine for the second time after receiving the first dose of AstraZeneca. In Spain, 2 million Spaniards received an English-style injection.
Vaccination restrictions AstraZeneca People under the age of 60 in Spain cause many people to receive only one dose of this vaccine. Therefore, the Carlos III Institute of Health (ISCIII)Promoted Clinical Trials This will assess the possibility of a second dose Pfizer In these situations.
This research is called Combination,will be 600 patients The possible protective effect and safety of taking the vaccine from the following locations Messenger RNA in order to Coronavirus disease It has taken at least 8 weeks since the first injection to thank people who have received treatment from a British laboratory for the first time.
During the presentation of the paper, the person in charge of ISCIII Raquel Yotti, Has stated that it will “generate scientific evidence” to verify the safety of combining other vaccines with the British drug, and “provide support for decision-making on alternatives to vaccines that have been immunized with a certain dose of AstraZeneca.”
During the clinical development of Comirnaty (Pfizer) and Vaxzevria (AstraZeneca) vaccines, different studies have been carried out to determine the dosage, efficacy, safety and conditions of use of each vaccine. Although the two have been in Europe for some time, so far, there is no clinical data about their possible combined use.
Combination seems to be possible and even desirable because they are vaccines with different mechanisms of action, and there is evidence that this approach to other diseases may be beneficial, but clinical trials like this one are needed to verify this. .
In fact, CombivacS is one of the first clinical trials to study the safety and immunogenicity of such a combination therapy.the study Will expand Five hospitals: La Paz and Clínico San Carlos in Madrid; Vall d’Hebron and Clinic in Barcelona and Cruces in Vizcaya. National Center for Microbiology (CNM) Will serve as the central laboratory for the test, which has been approved by the Spanish Agency for Medicines and Healthcare Products (Emergency action plan).
Quantitative antibody quantity
This is a phase 2 comparative, randomized and adaptive clinical trial designed to evaluate the safety and immunogenicity (the ability of the immune system to successfully respond to infection) in people who have previously been vaccinated with Coirnaty (Pfizer) vaccine. The amount of Vaxcevria vaccine (AstraZeneca).
The study analyzed the possible combinations of more than one vaccine (heterologous vaccination protocol) with different mechanisms of action to complete the required immunization. The initial hypothesis was that the immunogenicity was higher in people who received two different doses of the vaccine compared to a single dose of the vaccine.
Therefore, the main purpose of the test is to verify whether people who have received a certain dose of AstraZeneca vaccine have a significant increase in their anti-SARS-CoV-2 antibody levels at 14 days after receiving the vaccine dose.Pfizer
For logistical reasons, only those who live in the provinces where the five participating hospitals are located are eligible. The expected results will be obtained within 5 weeks after the start of the trial. If these results are beneficial to the safety and effectiveness of the sequential vaccination regimen, a certain dose of Pfizer will be provided to all participants in the control group.
Volunteers divided into two groups will participate in the trial, and they will be randomly assigned to the trial. On the one hand, the first group or intervention group consisting of 400 people will receive a certain dose of the Comirnaty vaccine (Pfizer), followed by 28 days of clinical observation and antibody analysis for one year.
For its part, the second group, which will consist of 200 people, will not receive any vaccines initially. The second group will serve as the control group, and all monitoring, safety and analysis procedures are the same as the experimental group. The comparison of the immune response between the two groups will be analyzed 14 days after each volunteer is enrolled, and will not affect other very detailed analyses that will be performed within a year.
Considering that participants will take at least 7 days to enter the study and thousands of samples must be analyzed, it is expected that no results will be obtained until 4 weeks after the first person receives the dose of Comirnaty (Pfizer). In any case, if the results indicate recommendations, Pfizer vaccine (Group 2) will be provided to all patients who did not initially receive the vaccine 28 days after the start of the study.
Finally, the researchers also sought to gain knowledge about the immune response conferred by the sequential combination of the two vaccines within one year, and the protective effect of SARS-CoV-2 variants 14 and 28 days after full vaccination.