The immune response that is generated after the inoculation of two doses of the anti-Covid vaccine, developed by AstraZeneca, is lower than that observed with the vaccine mix consisting of the first dose of Astrazeneca and the second dose of mRna. And, moreover, even compared to two doses of mRna vaccine. This was specified by the World Health Organization in the context of the new recommendations on AstraZeneca’s anti-Covid vaccine, developed on the basis of the assessments released by the Strategic Advisory Group of Experts on Immunization (SAGE).
The use of a mix of vaccines
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The experts, according to which the heterologous regimen does not seem to have the same efficacy, however, if the first dose is at mRna and the second with AstraZeneca, have explained that resorting to the mix of vaccines, may be necessary only in particular situations of interruption in supplies. , also because these studies are related to a limited sample of patients.
Caution in interpreting data
Furthermore, WHO experts explained that with the mixed regimen of anti-Covid vaccines there was also a greater, albeit acceptable, reactogenicity, i.e. local and systemic reactions following the inoculation of the drug. “Even if the data are encouraging at the moment, caution is needed in interpreting them”, the scholars have stressed in updating the recommendations regarding the AstraZeneca vaccine. Especially considering, as mentioned, “the limited sample examined and the lack of follow up, especially on safety data”. Currently, in fact, no studies have been produced on the efficacy of the vaccine in a heterologous regimen. “The more data coming soon, the more new recommendations,” the scientists confirmed. The heterologous regimen, concluded the WHO, “is to be considered off-label and there are currently no data to prefer the heterologous regimen over other vaccines”.