AstraZeneca is already used in more than 180 countries and Pfizer in more than 145 countries. Undoubtedly the two best-studied types of vaccines, their combination was the subject of research for the first time on heterogeneous and booster vaccines – readable on the gate.
Previous research has also shown that two doses of AstraZeneca provide 70 percent and two doses of Pfizer provide 90 percent protection against hospitalization 6 months after vaccination — but we also know that protection decreases over time, and it now appears certain that a booster dose is needed.
The COV-BOOST study looked at the third dose based on the immune response and safety of the booster doses, ie the frequency and severity of side effects. The researchers examined AstraZeneca, a Pfizer, a Novavax, a Janssen, a modern, a Valniva and the korevac Vaccinations as a booster after two AstraZeneca or two Pfizer vaccines.
All seven vaccines were safe for side effects, most commonly for local inflammatory reactions (injection site pain, muscle aches, and fatigue). Each vaccine elicited an adequate immune response to the spike protein when administered after AstraZeneca, but only six said after Pfizer, and Valneva did not perform well at the time. It is important to note that the immune response is limited to the number of antibodies and T-cell immunity in the research.
However, studies measuring the efficacy and safety of booster doses 7-8 months after the first series of vaccines will be required, as in the current phase II study, participants received a booster dose 10-12 weeks after the first two vaccines.
A total of 2,878 people, over the age of 30, participated in the research, and half of the team members were over the age of 70. After 28 days, the antibody response to the booster vaccines was robust regardless of age.
