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New Kid in Town | Frances Chai
There’s a new kid in town and their name is Johnson. To clarify, the word “new” here is used to describe the Johnson & Johnson vaccine’s debut on the distribution stage –– this vaccine has been in the works since January of 2020. In July of that year, Phase 1/2 trial began. Two months later, in September, a Phase 3 trial was launched by the company. This trial was paused on October 12, 2020 in order to investigate a negative reaction in a volunteer and was resumed later that month (on October 23, 2020). On November 16th, a second Phase 3 trial was announced with the purpose of observing “the effects of two doses of their vaccine.” At its full enrollment, this trial had approximately 45,000 participants. On February 24th, it was revealed that the Johnson & Johnson vaccine has a 72% overall efficacy rate in the United States and a 64% efficacy rate in South Africa (the location of the B.1.351 variant). Three days later, the Food and Drug Administration authorized the vaccine for emergency use.
Distribution of the US’s third COVID-19 vaccine is projected to happen immediately –– a senior Biden administration official announced that this shot could be adminsitrated as early as Tuesday, March 2nd. Within the week, four million shots are expected to be delivered. By the end of this month, 20 million shots are planned to be distributed. With this schedule, hopefully the company is able to fulfill their promise of having 100 million doses available by summer.
How does the Johnson & Johnson vaccine differ from its Pfizer and Moderna predecessors?
Unlike both the Pfizer and Moderna vaccines, this one only requires a single dose.
The efficacy rate of the Johnson & Johnson vaccine is lower than that of Pfizer and Moderna, however, this vaccine was tested within different populations in different areas (US, South Africa, and Latin America while Moderna tested exclusively in the US and Pfizer tested in the US, Germany, Turkey, South Africa, Brazil, and Argentina) later in the pandemic than the other two vaccines. This means that the Johnson & Johnson vaccine has been tested against variants, something that was missing in the early trials of the other two vaccines. All in all, experts are in agreement that all vaccines provide good protection against serious illness.
With this new vaccine, protection begins around two weeks after the shot is administered. The clinical trial data shows no deaths or hospitalizations by four weeks after the shot. In comparison, full protection with the Moderna and Pfizer vaccines does not come until around two weeks after the second dose, translating to five to six weeks after the first dose.
Moderna and Pfizer use mRNA technology while Johnson & Johnson uses viral vector technology (a genetically engineered common cold virus called adenovirus 26).
The Pfizer and Moderna vaccines must be kept at specific temperatures and carefully handled (for the Pfizer vaccine in particular, dry ice and special freezers had to be procured for storage). The Johnson & Johnson vaccine can be stored at simple refrigerator temperatures for up to three months (in comparison to the five day refrigerator shelf life of the Pfizer vaccine).
As we near the one year anniversary of quarantine, it is definitely nice to see that more and more vaccines are being made available. However, with a return to normalcy on the horizon, it is more important than ever to remain safe. Yes, people are being vaccinated but the pandemic is still taking lives and putting people in hospital beds. We are not yet in the clear.