The European Medicines Agency (Ema) and the European Center for Disease Control and Prevention (Ecdc) have authorized heterologous vaccination, the use of two types of anti-Covid vaccines, both for the first vaccination and for the booster dose.
“Evidence from heterologous vaccination studies suggests that the combination of viral vector vaccines and mRna vaccines produces good levels of antibodies against Sars-CoV-2 virus and a higher T-cell response than using the same vaccine (vaccination homologous), both in primary and booster regimens. The heterologous regimens were generally well tolerated “, reads the Ecdc-Ema recommendation.
Third dose Covid vaccine, which boosters work the most?
by Noemi Penna
“The use of a viral vector vaccine as a second dose in primary vaccination schemes, or the use of two different mRNA vaccines, is less studied,” it continues.
“The currently available evidence consistently points towards acceptable tolerability and improved immune responses with the sequential heterologous vector vaccine / mRNA vaccine regimen compared to the homologous vector vaccine regimen,” the two European agencies’ reports write. “Some studies have reported greater reactogenicity (pain, fever, headache, fatigue) of heterologous vaccination, but the results are not consistent.
Covid, third dose: “No advantage in alternating Moderna and Pfizer”
by Cinzia Lucchelli
Regarding the rarely occurring adverse reactions, there are insufficient data to draw conclusions “, they write again.” Regarding immunogenicity, the studies are consistent in demonstrating that the heterologous regimen is capable of significantly inducing immune responses. increased, including enhanced memory B cells, compared to a homologous viral vector regimen. A slight increase in humoral immune responses is sometimes observed compared to homologous mRNA vaccination, but not consistently, in support of a similar antibody response, “the recommendations also read.
Covid vaccine, Locatelli: “Fourth dose as a concrete possibility”
.