Disclosure of the secret mixture of Johnson & Johnson vaccine

The Johnson & Johnson single-dose vaccine is now the fourth authorized by the European Union to fight COVID-19.

AFP spoke to Johnson & Johnson's scientific director, Paul Stoffels, about what that means for the battle against the pandemic.

The interview has been edited for greater clarity.

AP: What makes the Johnson & Johnson vaccine so important?

Stoveles: The vaccination process is with the vaccine that the European authorities have just licensed, with a single dose, and it is the first vaccine that has been studied on a large scale (about 40,000 people), including the mutated versions.

We found it to be very effective against severe illness and those requiring hospitalization and death.

In addition, it is composed of a single dose that can be charged at a temperature between two to eight degrees Celsius, which is a normal cooling temperature, which will facilitate its widespread use in the world.

AP: What is your response to the criticism that the Johnson & Johnson vaccine does not protect like vaccines using the "messenger DNA" (RNA) technology made by Pfizer and Moderna?

Stoffels: We conducted our study globally in three continents: the United States, South America and South Africa, but also in very difficult conditions in terms of the spread of the epidemic.

We now know how effective the vaccine is on the mutated versions and it can be shown that independently of the mutated region, version, or age, it protects against severe disease, death, and the need to transfer (the patient) to the hospital.

That means 85 percent protection from severe disease, but also 100 percent so far.

After the 28th day (that is), we have not seen people who are hospitalized or die, which is the most important challenge in this disease.

AP: The Johnson & Johnson vaccine uses the adenovirus that causes the common cold, in a genetically modified form that prevents it from reproducing, as a "vector" to carry the gene in a part of the Corona virus to human cells in order to train the immune system.

What is the biological advantage of this approach?

Stoveles: We have a good response with respect to antibodies, but it's cellular immunity that makes it sustainable and broad in scope as well.

We already learned that as we developed an Ebola vaccine, a Zika vaccine, and are working on an HIV vaccine.

The secret mixture for such a vaccine is a mixture of the two.

AP: Can you explain in simple terms what cellular immunity is?

Stoveles: When you get a graft as a child, you get vaccines that will protect you throughout your life.

So your body memory preserves this disease factor.

Although many will not need to measure the antibodies anymore, the body remains able to respond because it immediately recognizes the causative agent of the disease that it tested before.

Hence the importance of cellular immunity, both for immediate efficacy and for long-term memory.

AP: What is the status of your studies with regard to children and pregnant women?

Stoffels: At the moment, we're studying vaccination for teenagers, and it's continuing, from 12 to 17 years old.

Phases 2 and 3 (when efficacy studies begin) for children under 12 years of age begin in April.

Studies in pregnant women will begin now.

AP: Are you going to develop specific vaccines for the mutated versions?

Stoffels: Just in case, we have already started manufacturing a vaccine based on the metamorphic version in South Africa.

We don't know if we will need it, but if we need it, it is on the way and we are currently in the early stages of development.

AP: Some scientists have raised concerns about the issue that replicating the vaccine will be a problem given that the immune system will remember the virus that was used as a vector and will attack it, which reduces the effectiveness.

Would that be a problem for reinforcers?

Stoffels: In our work related to HIV, we exposed people to the vector four times over a year.

Although we have seen small changes, we have not seen that we cannot use it as a reinforcer.

Adenovirus 26 was chosen as a vector, which we have, because it has low immunogenicity and low human presence.

We are reasonably comfortable that the vaccine can be enhanced without problems.

AP: Is there anything else we should know?

Stoffels: We have a very comprehensive network in the world to make sure that we can serve the entire world, and we are also cooperating with Kovacs (the UN mechanism for ensuring equitable access to vaccines).

We hope that after what we do in the United States and Europe, we can vaccinate the entire world quickly.

And we have a significant commitment at Johnson & Johnson to do this at a non-profit rate.