How are the three leading Covid-19 vaccine candidates different?

Moderna, Pfizer / BioNtech and AstraZeneca, Although there are hundreds of projects underway, it is these three vaccine candidates that have taken the lead offering hope to the world

MADRID.- The announcements of the pharmaceutical companies Moderna, Pfizer / BioNtech and AstraZeneca, those of the latter in collaboration with the University of Oxford, place the use of vaccines against covid-19 one step closer, but how are they different? these projects in phase III? What are your strengths and weaknesses?

Although there are hundreds of projects underway, it is these three vaccine candidates that have taken the lead. Its efficacy results offer hope, but the scientific community agrees that we still have to be prudent and cautious because it is provisional data and there are many details to be revealed.

The vaccine developed by the English University of Oxford and this company has an average efficacy of 70.4% (depending on the doses, the effectiveness ranges between 62% and 90%), according to the preliminary results released this Monday by the consortium .

These data differ from the 94.5 and 95% effectiveness reported by Moderna and Pfizer, respectively. These are all results of clinical trials in phase III, the last of the stages.

Clinical trials have three phases plus a fourth review phase, applicable only when the drug or vaccine already has the approval of regulatory agencies and is on the market. Each of the stages of an essay is designed to answer a few questions.

In this case, it is being verified whether immunization truly protects the population against exposure to the pathogen. Regulatory agencies have begun reviewing phase III results, although none have been published in scientific journals.