The Slatest

Johnson & Johnson Starts Phase 3 Trial for Single-Dose Coronavirus Vaccine

A patient is given a shot during a vaccine trial.
Multiple vaccines will likely be required to vaccinate billions of people to sufficiently suppress the virus. David Greedy/Getty Images

American pharmaceutical giant Johnson & Johnson announced it has begun Phase 3 trials of a coronavirus vaccine after promising signs in earlier phases of development. The company’s vaccine candidate is the fourth potential vaccine to go into the crucial third phase of testing in the U.S., but, if successful, the Johnson & Johnson vaccine would carry significant benefits over the other treatments currently being tested. The biggest advantage is that it would only require a single jab, rather than a repeat visit to the doctor for multiple injections over several weeks, and it could be stored more easily, as it only requires refrigeration-level storage to be kept up to three months. The other front-runners need to be frozen in order to be stored long term.

Phase 3 trials greatly expand the pool of participants to gauge a drug’s effectiveness—comparing it with a placebo—after the preliminary phases explore whether there is any glaring safety issue in a far smaller sample of volunteers. The Johnson & Johnson vaccine candidate prompted the body to produce an encouraging level of antibodies, which, if effective, would then be expected to ward off the virus. “The J&J vaccine is the second to use a viral-vector approach, taking a harmless virus and inserting into it a gene that contains the blueprint for a distinctive part of the novel coronavirus,” the Washington Post notes. “In a monkey study published in Nature in July, [the J&J vaccine candidate] showed [its] approach successfully taught the immune system to protect against a real infection.”

Now comes the international trial, which aims to involve 60,000 participants from the U.S., as well as from a handful of countries in the Americas—Argentina, Brazil, Chile, Colombia, Mexico, Peru—and South Africa. The number of participants in the trial is higher than normal Phase 3 trials, which could help the company accrue enough data on the drug to determine its safety and efficacy more quickly in order to get it to market faster.

The simplified logistics of a single-dose vaccine that is easily stored and administered will be of paramount importance as the country and the world embark on a mass vaccination campaign once vaccinations become available. Simply producing enough doses will be a mammoth undertaking, though the U.S. has already invested billions to secure doses of a variety of vaccine candidates whether or not they ultimately work or ever get used. The aim is to speed up the process by underwriting different leading pharma companies’ vaccination development, essentially writing off the loses of companies’ failed attempts to incentivize lots of drugmakers to take lots of shots at a vaccine. The U.S. government has, for instance, already invested $1.5 billion in Johnson & Johnson’s vaccination drive and secured 100 million doses.

At a news conference on Tuesday, Dr. Paul Stoffels, chief scientific officer of Johnson & Johnson, said the company could determine by the end of the year whether the drug is safe and effective, and that the company plans on manufacturing 1 billion doses next year. The race to create a vaccine is not a zero-sum game, however, and the thinking in the public health world is that multiple vaccines, using different types of designs to combat the virus in different types of people, will be required to vaccinate billions of people to sufficiently suppress the virus.