What do you know about COVID-19 vaccines?
My name is Jonathan Makassa. I have a master degree in biotechnology and nanotechnology and today I want to talk to you about COVID-19 vaccines. As you all know the pandemic is still out there and all people are wondering whether our lives will ever get back to where they were before. Are we all obliged to get vaccinated and if yes which vaccine is the most appropriate and the safest? If you are one of them this video is for you.
According to Gavi, the Vaccines Alliance, vaccines are regrouped into four groups: whole viruses vaccines, protein subunit vaccines, nucleic acid vaccines and viral vector vaccines. Whole viruses vaccines use two main approaches. The first one is life attenuated vaccines where the virus is used to trigger the immune response. The virus still can replicate but cannot cause the illness. The second approach is the inactivated vaccines where the virus is inactivated and cannot replicate in the cell but can increase the immune response.
The second type of vaccines is protein subunit. Here we don’t use the full virus we just use one part of it. Usually, we use the protein that causes the disease as an antigen to create immune response. These vaccines have fewer side effects but sometimes they create a weak immune response that is why we usually add adjuvants to them.
The third type is nucleic acid vaccines. They use the nucleic and genetic information to communicate or deliver this information to the cell so the cell will produce its own antigens, then will let it be recognized and be killed. This type of vaccines is usually easy and cheap to make.
The fourth form of vaccines is the viral vector. They are a bit similar to the nucleic acid vaccines. Only they use a virus. A different virus from the one the vaccine is targeting to deliver the genetic information.
For the COVID-19 it was used ChAdOx1 which is a chimpanzee adenovirus that was inactivated genetically. So that it will not replicate in the cell. After the virus falls in the cell there is endocytosis, then the virus containing the DNA of COVID-19 SARS-2 goes into nucleus where it releases that information in the nucleus for the messenger RNA to be sensitized from the DNA. That messenger RNA will later move to the cytoplasm where we will have a translation. The spike proteins of SARS-2 can be sensitized by the cell and those proteins will later migrate to the surface of the cell. Then the cell that was vaccinated can be recognized be B-cells and killer T-cells.
In this video I want to tell you about 5 types of vaccines: Pfizer, Moderna, Johnson&Johnson, Astrazeneca and Sputnik. Pfizer and Moderna use the technology of a messenger RNA, they are nucleic acid vaccines that trigger the immune response. Johnson & Johnson, Astrazeneca and Sputnik V at the reverse use a viral vector for instance the adenovirus to deliver the DNA of the COVID-19 into our cells to produce the immune response. Clinical trials have showed the different level of efficiency. According the official sources Pfizer has showed 95% efficiency, Moderna has showed 94%. But after second dose it was not very efficient for people who are over 65 years old. Johnson & Johnson shows 85% of efficiency and most particularly for different hard forms the virus infection. Sputnik V has shown more than 90% efficiency. Astrozeneca has showed 90% at first dose and only 62% at second dose.
I hope this was useful and thanks for watching