Pfizer's vaccine is a messenger RNA vaccine, which involves injecting the genetic material of the virus into human cells. The immune system then recognises the material as foreign and produces effective antibodies against the virus.It was the first vaccine to be approved by the World Health Organisation (WHO). Tunisia granted it marketing authorisation (WMA) in January 2021, but the first doses only arrived in mid-March via COVAX (a WHO initiative), as well as through direct purchase from Pfizer.

Like Sputnik V, the AstraZeneca/Oxford's vaccine is a viral vector vaccine. After several cases of serious side effects among relatively young people, many countries, such as France and Belgium, have decided to administer the vaccine only to those over 55 years of age. Tunisia received the first doses of this vaccine in early April 2021. The scientific council subsequently recommended that it be used only for people over 60 years of age.

The Sputnik V vaccine is a viral vector vaccine. As with the messenger RNA vaccine, it is based on the genetic material of the virus, the only difference being that it is injected into human cells via a harmless virus. The virus then replicates and spreads, triggering the body's immune response. The 30,000 doses received at the beginning of March enabled Tunisia to commence its vaccination campaign. The Russian vaccine was therefore the first to arrive and be distributed on Tunisian soil.

The CoronaVac vaccine from the Chinese company Sinovac is an inactivated virus vaccine. As the most conventional method, it involves injecting a chemically inactivated form of the virus into the cells. The human body then identifies the virus and produces antibodies to neutralise it. The overall efficiency rate of CoronaVac is 50.38% following the second dose, which is one of the lowest rates among the vaccines obtained by Tunisia. Tunisia obtained the vaccine as a donation from China. After Sputnik V, CoronaVac was the second vaccine to be administered throughout the country.

Like Sputnik V and AstraZeneca/Oxford, the Johnson & Johnson vaccine is also a viral vector vaccine. What separates it from the other two vaccines is that it only requires one dose instead of two. There have been reports of serious side effects in the US. However, the European Medicines Agency decided to still distribute the vaccine in Europe as these side effects are considered to be very rare. The first doses of the vaccine were received at the end of July 2021, and were donated by France.

Comme Coronavac, le vaccin Sinopharm est un vaccin à virus inactivé. Cette méthode traditionnelle consiste à injecter une forme inactivée chimiquement du virus à l’intérieur des cellules. Le corps humain identifie alors le virus et produit des anticorps pour le neutraliser. Le taux d’efficacité global de CoronaVac est de 79%, une fois la seconde dose injectée.

Like Pfizer, the Moderna vaccine is a messenger RNA vaccine, and consists of injecting the genetic material of the virus into human cells. The immune system recognises it as foreign material and produces effective antibodies against the virus. On July 30, 2021, the United States delivered one million doses to Tunisia as part of the Covax initiative.