LONDON — Health care systems around the world are struggling to cope with rising numbers of Covid-19 infections as they race against the clock to vaccinate the vulnerable.
The three vaccines currently approved for use by major Western economies all require two separate jabs and given supplies are limited, governments are considering contentious tactics like stretching the length of time between doses to get at least one dose to as many people as possible.
A one-shot vaccine could significantly improve our ability to fight the virus — and we may have one soon.
Johnson & Johnson is expected to deliver preliminary late-stage trial results for its one-dose Covid vaccine candidate by the end of January. If its jab is proven to be safe and effective, the company aims to deliver at least 1 billion doses by the end of the year.
The J&J vaccine was developed by the company's Belgian unit, Janssen Pharmaceutica, and is based on viral adenovirus vector technology, the same approach used to create the University of Oxford-AstraZeneca vaccine. This type of shot is easier to scale up than those developed by Pfizer-BioNTech and Moderna which are based on messenger RNA technology.
Health care analyst Adam Barker at Shore Capital said in an email to CNBC last week: "The J&J vaccine is more like the AstraZeneca vaccine, but it uses only one dose. So we know this approach works (viral-vector) and it targets the spike protein. We know that target works too. But, we'll have to see what one dose does."
Morgan Stanley's health care team said in a research note published last week that J&J's vaccine offers "unique elements and efficacy could surprise to the upside relative to AstraZeneca driving confidence in pandemic response and market recovery."
The investment bank is confident in the safety profile of the vaccine given early trial data, "along with the prior success and safety profile demonstrated in their Ebola vaccine as well as in investigational use in HIV, RSV and Zika."
A report by the Tony Blair Institute for Global Change, which is founded by the former British prime minister, calls the AstraZeneca and Johnson & Johnson jabs "the two workhorse vaccines" because these should be deliverable at scale and are easier to administer than the mRNA shots.
With J&J's technology, the vaccine is estimated to remain stable for at least three months at normal refrigerated temperatures so does not require new infrastructure to transport.
J&J completed enrolment of its 45,000-participant phase three clinical trial for its single-dose vaccine candidate on December 17. Preliminary data from the trial is expected to be available by the end of the month.
If the data indicates the vaccine is safe and effective, the company expects to submit an Emergency Use Authorization application to the U.S. Food and Drug Administration in February. Other health regulatory applications around the world are expected to be made in parallel.
The company has committed to selling the vaccine on a not-for-profit basis for emergency pandemic use.
J&J entered into an agreement with the U.S. in August 2020 to deliver 100 million doses of the vaccine following approval or emergency use authorization by the FDA, and the option to purchase up to 200 million additional doses under a subsequent agreement.
The U.K. negotiated a deal in August to initially purchase 30 million doses of the J&J vaccine with an option to purchase up to 22 million additional doses. The EU signed a deal with J&J in October for the supply of up to 400 million doses.
J&J has also agreed to provide up to 500 million doses of its vaccine as part of an agreement in principle with The Vaccine Alliance (Gavi), which is responsible for equitable access to vaccines, including to lower-income countries via COVAX. These doses will be distributed through 2022 if the vaccine candidate is approved for use.
"If J&J's Ad26 platform is able to confer 80%+ efficacy via a single-dose regimen, given the vaccine's favourable handling requirements and significant manufacturing scale, we would view this as a compelling outcome," said Morgan Stanley.
As for what governments should do in the meantime, Jonathan Reiner, professor of medicine and surgery at the George Washington University School of Medicine & Health Sciences argues: "The J&J vaccine is why we should not abandon the two-dose strategy for Pfizer-BioNTech and Moderna. We're likely to have all the vaccine we need. We need to focus on getting the vaccines into arms."