The third dose of vaccine for a further reminder in winter it is still a puzzle. But among the United States and the UK Trials have started to study them, even with a different serum than the first anti-Covid vaccination cycle. The hope – confirmed by the first experimental results – is that even a different dose can counteract the evolution of the virus through the variants of the coronavirus. The need for a third recall is still under study and has not been made known by the authorities at the moment, but it could only concern some sections of the population, the weakest. Also on the “mix“of vaccines (between the first and second dose) there are no official communications, despite the governments pushing for a response from the EMA. In fact, some studies, including a Spanish published in Nature and another English, demonstrate the efficacy of a second different dose: this would allow the body to produce more antibodies, albeit with side effects slightly higher. For this reason, even a possible third dose could have the same positive effects.
Covid, vaccine mix for first and second dose: the EMA may not have enough data for the ok
THE USA STUDIO – The experimentation is in the early stage, but the National Institute of Health he explained that he wanted to understand what happens when an adult who has already completed his vaccination cycle with one of those approved by the EMA, receives a different third dose. The program will involve 150 men and women who have already been administered one of Johnson&Johnson, Pfizer or Moderna, that is, one of the vaccines authorized by the FDA (and among which there is no longer AstraZeneca). The booster will come 12-20 weeks after the second dose. “We must prepare for the eventuality of a further recall to avoid the spread of the virus and variants – explained the American virologist Anthony Fauci -. This study will guarantee information on the mix of vaccines, whose eventual program will then be established by the authorities ».
THE UK TRIAL – In UK instead the program that will study the booster with third dose is called Cov-Boost and will start in June: it will involve about three thousand adults (over 30 years old) who received the first dose between December and January and who have already exceeded 84 days from the recall. Not only third doses will be tested with AstraZeneca, Moderna and Pfizer but also Johnson & Jonhson, Valneva, Novavavax and CureVac. The researchers explained that “variants of the Sars-Cov-2 virus can make the immune response to vaccination less effective. The recalls for some groups, particularly those at high risk, could provide additional protection ».