J&J’s Vaccine Results Are In. So What’s the Verdict?

Sam Fazeli, a Bloomberg Opinion contributor who covers the pharmaceutical industry for Bloomberg Intelligence, answered questions about Johnson & Johnson’s Covid-19 vaccine after the drugmaker released results from a large, late-stage trial. The conversation has been edited and condensed.

Johnson & Johnson’s vaccine — a single-shot dose that’s easy to store, unlike others now in use — has been seen as a potential game-changer in the Covid-19 fight, and so these trial results were eagerly anticipated. Are they as good as people were hoping? 

Yes and no. The overall efficacy of 66% is not as good as what’s been shown in the shots developed by Pfizer Inc.-BioNTech SE, Moderna Inc. and Novavax Inc., but this was skewed by the inclusion of data from trials in Latin America and South Africa. When you just look at the U.S., the efficacy was 72%, which is better, but even this perhaps falls short of the hope of 80% or so. J&J suggested that its U.S. efficacy may be lower because of new and unknown variants circulating in the country,  but that seems far-fetched given that Novavax managed an 86% efficacy in the U.K. even in those infected with the B.1.1.7 variant that emerged there.  Still, the vaccine did have 85% efficacy against severe disease and 100% efficacy against hospitalization or death. So it’s a valuable addition — especially when you also consider J&J’s manufacturing might.

Is there something in how the vaccine is made that may make it more or less effective than other types?

Well, this trial is looking at only one dose, so there is no booster like the others now in use, which may explain the lower efficacy. Still, those others had close to 90% efficacy 15 days after the first dose and before the second dose, so on the surface it doesn’t quite match up to those. But we simply don’t know what would have happened to the efficacy of the other vaccines if they had not included a second booster dose. J&J is conducting a two-dose trial with a 57-day interval between the two doses. We will have the results of that trial later in 2021.

What do the findings means for the vaccination effort and rollout?

It’s a positive development despite the slightly disappointing efficacy results. J&J has pledged to sell the vaccine at cost, at least during the pandemic. This means that the vaccine will be more affordable for many lower-income countries. It’s also much easier to ship, store and use because it can be kept under normal refrigeration for at least three months. So all in all its a much easier vaccine to get into people’s arms. Bottom line, we need as many tools as possible in the pandemic fight, and this vaccine has the potential to do a lot of good, even with the unknowns.

What's new in this data that wasn't in other trials?

The critical new piece of information is the data from other geographies, especially South Africa, where the B.1.351 variant has emerged. The efficacy was much lower in that region, at only 57% (as a reminder, 50% is the minimum efficacy level regulators would like to see before considering emergency use approval). Nearly all of the South African participants were infected with that B.1.351 variant, which has already been shown to be less responsive to treatments using plasma from convalescent patients. The lower efficacy related to the variant corroborates with what Novavax found in its own South African trial. Also, J&J’s South African trial included just more than 1,200 subjects with HIV, while Novavax’s had 245 with the virus that causes AIDS. There is a chance that the variant virus may have evolved in these HIV patients, although this isn’t yet proved. Taken together, though, these findings — along with J&J’s comments about possible variants effecting overall efficacy in the U.S. — suggest we need to be working on next-generation vaccines, and all the companies are doing that. It also means that the level of surveillance for these variants, by doing full genomic sequencing, has to increase significantly in all regions.

Can J&J’s vaccine be modified to work better against variants like the one in South Africa?

This is a little bit of a concern. J&J’s vaccine uses an existing virus — one from the large family of viruses that cause the common cold, called adenoviruses — and has it engineered to deliver the genetic material for the Sars-Cov-2’s key “spike” protein instead. This causes the immune system to raise a response to the spike protein as well as other parts of the virus that is used to deliver the material. It’s the same technology used in the shot developed by AstraZeneca Plc and the University of Oxford. What we don’t know is whether this approach lends itself to several iterations of the vaccine or whether it will induce an immune response that may diminish its efficacy on repeated use. This is less of an issue with the shots developed by Pfizer-BioNTech and Moderna, which use messenger RNA to instruct cells in the body to develop virus proteins that then trigger a response. This mRNA can be tweaked more easily to target variants and instruct the body to mount just as robust a response. But even here, there may be a limit to the number of different variants that can be represented in one shot. The technology that is best suited to repeated use as a “multi-valent” vaccine is the one that Novavax has developed, and luckily that has shown a very strong efficacy.

When can we expect approval?

J&J is expecting to file with the U.S. Food and Drug Administration for emergency use approval of its vaccine in the next week or two. This would allow a potential approval by the end of February. As for other countries, it will likely be in March. The issue is that J&J does not have a large number of doses to deliver immediately, with its pledge of 100 million doses of vaccine for the U.S. aimed at June 2021. Manufacturing should ramp in the second half of the year. It was not clear from J&J’s comments how many doses it can deliver internationally, with a pledge of 200 million shots to the European Union and 30 million to the U.K. 

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Bloomberg Opinion provides commentary on business, economics, politics, technology and markets.

©2021 Bloomberg L.P.

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