Other COVID-19 vaccines

Strengths and weaknesses of the different most advanced candidates

How Would COVID Vaccines Work in Your Body

Oxford University and AstraZeneca

Name: AZD1222

  • It belongs to the team of non-replicating viral vector vaccines.
  • It was built from an adenovirus, a type of virus that does not harm our health. Inside it, the scientists inserted some Sars-CoV-2 genes to provoke an immune system reaction.
  • According to the analysis of 131 cases of covid-19, this vaccine proved to be 70.4% effective when combining data obtained from a regimen of two administered doses. Researchers estimate, however, that this efficacy can reach 90% if the dose is adjusted.
  • As of yet, no approved vaccine uses this type of methodology. On the one hand, this can work and revolutionize knowledge in the field. On the other, it is necessary to wait patiently for the definitive results on the effectiveness and safety of the product.
  • An advantage of the University of Oxford and AstraZeneca vaccine is in its availability
  • Another advantage of this compound is that it can be stored between 2 and 8 ° C, so it can be distributed and preserved with existing logistics capabilities.


Name: CoronaVac

  • Sinovac is also betting on the inactivated virus strategy.
  • The scientists used some method, such as heat or chemicals, to deactivate Sars-CoV-2 to not cause infection or reproduce within the body. Even so, when applied in a vaccine, the virus is recognized by the immune system, creating a protective response
  • The strong point here is reliability. Science has been working with inactivated virus vaccines for almost seven decades. The weak point is the delay. Manufacturing requires too high rigor and a very well equipped industrial plant.
  • The formulation also does not yield much in doses per liter. The product is in Phase III testing and soon expects to complete the minimum number of events (volunteers infected with covid-19) to calculate its effectiveness rate.

Gamalaya Center for Research in Epidemiology and Microbiology

Name: Sputnik V

  • The Sputnik V researchers announced effectiveness of 92%, based on 20 recorded events.
  • We have to wait for the study to evolve a little more for this rhythm to consolidate.
  • It is speculated that the immunizer does not require freezing, but that information has yet to be confirmed


Name: NVX-CoV2373

  • This is the most advanced representative of the class of protein subunit vaccines. Instead of using the whole virus, it was developed from a small fragment of Sars-CoV-2 capable of activating an immune response.
  • Part of the Phase III studies are being carried out in the UK with 15,000 volunteers, with preliminary results expected in January or February 2021.
  • The Novavax product is part of Covax (WHO consortium for the purchasing and distributing doses to less developed countries).


Name: Ad5-nCoV

  • Made from a non-replicating viral vector (such as Oxford University / AstraZeneca candidates Sputnik V and Johnson & Johnson), it was emergency approved for use by Chinese military personnel, even before major security studies. and efficiency.
  • In Phase III trials, Ad5-nCoV is currently applied to more than 40,000 volunteers from Pakistan, Saudi Arabia, and Mexico.
  • There is little information on this vaccine.

Bharat Biotech

Name: Covaxin

  • Developed in India, it is one of the latest candidates to enter Phase III clinical trials. Like CoronaVac, it also uses inactivated viruses in its formulation.
  • There is a great deal of world experience in using this technology, although it is expensive and time consuming compared to more modern methods.