FDA finds one-dose J&J shot effective
Likely to become third vaccine authorized in US
Detailed information on a Johnson & Johnson candidate vaccine for COVID-19 raises no safety concerns, according to a report released early Wednesday.
A Food and Drug Administration advisory committee will hold an allday meeting Friday to review the data and is likely to give the vaccine a thumbs-up, leading to an expected FDA authorization for the vaccine in adults within the next few days.
The J&J vaccine differs from the two already authorized, because only one shot is recommended, instead of two.
The company also is studying a two-dose regimen, which might prove more effective or more durable, in which case people might be encouraged to get a booster shot.
The Vaccines and Related Biological Products Advisory Committee, or VRBPAC, is likely to sign off on the vaccine because it seems to have met all the criteria for authorization the FDA established last year.
Like the Moderna and Pfizer-BioNTech vaccines, the one from J&J underwent a large clinical trial showing its safety and effectiveness, and the
company proved it can manufacture the vaccine in a safe and consistent manner.
Once the committee gives its OK to the vaccine, it will be up to the acting FDA commissioner to authorize it, which could happen within a few days.
The vaccine already is used in South Africa, and the company applied to the European Union and the World Health Organization for authorization.
J&J agreed to provide 100 million doses of its vaccine in the USA by June, including 20 million by the end of March. Those doses will add to the 300 million doses Pfizer-BioNTech and Moderna each have promised to deliver to the U.S. government by the end of July.
The vaccine was shown to be 72% effective in a trial in the USA in which all ethnic, racial and age groups benefited about the same.
Trials of the vaccine in other countries have shown less effectiveness – 66% in Latin America and 57% in South Africa, 28 days after the shots – probably because of variants of the virus circulating in those countries.
The same variants are circulating in the USA but not in very high numbers, so the vaccine is likely to be useful here, particularly because it requires only one dose.
Although the J&J vaccine appears less effective than ones from PfizerBioNTech and Moderna, it’s hard to make direct comparisons because those trials were conducted months earlier at a different point in the pandemic when there were fewer known variants.
The J&J vaccine was shown to be 85% effective in preventing the most severe disease across all regions studied 28 days after the shot and proved more effective over time. No cases of severe disease were reported after Day 49 among those who were vaccinated. The company defined severe disease as respiratory failure, shock, organ failure or the need for treatment in a hospital intensive care unit.
The vaccine can be stored in a refrigerator for three months and in a freezer for up to two years, making it relatively easy to distribute through typical medical supply systems.
The FDA is awarding COVID-19 vaccines emergency use authorization rather than full approval.
Although all the testing has been comparable to tests required for full approval, the vaccines have not been required to show longer-term data, which would delay their distribution during the pandemic. All the companies are likely to eventually apply for full approval.
Two more companies are likely to request authorization for their vaccines in the next few months. AstraZeneca, working with Oxford University, developed a vaccine that finished enrolling volunteers in its large-scale trial in January, and Novavax announced last week that it had completed enrollment.
Both companies must wait to apply for authorization until at least half their participants are eight weeks out from their second shot, and until enough participants in both placebo and active vaccine groups have come down with symptomatic COVID-19 to determine their vaccine’s effectiveness.
The AstraZeneca-Oxford vaccine already has been authorized for use by the World Health Organization. South Africa has delayed using the vaccine until it can be tested further, because an earlier trial suggested it was not very effective against the dominant variant in that country.
The J&J trial, in which half the participants received an active vaccine and half a placebo, did not include children or pregnant women.
In terms of demographics, 38% of participants were older than 60, and 55% were male. Of the nearly 20,000 participants in the USA, 74% were white, 15% Hispanic, 13% Black, 6% Asian and 1% Native American.
More than 40% of the trial participants globally had medical conditions putting them at higher risk for severe COVID-19, including obesity, Type 2 diabetes, hypertension or HIV. People with these medical conditions were not any more likely to develop COVID-19 than people without symptoms, suggesting that the vaccine provides protection regardless of underlying illnesses.
Nearly 10% tested positive for COVID-19 at the start of the study.
Among the 682 trial participants who fell ill with COVID-19 at least two weeks after their shot, 75% had received a placebo. People over 60 seemed no more likely to fall ill than younger people.
Participants who were Black were only slightly more likely to fall ill than others, representing 21% of the vaccinated group and almost 20% of the placebo group. American Indian participants, including those in Latin America, were slightly more overrepresented, accounting for 12% of those who were vaccinated but only 8% of those in the placebo group.
Overall, the vaccine appeared to be more effective over time, the gap between the placebo and vaccinated groups widening from two weeks to three months after vaccination.
It seemed to be highly effective against severe disease, particularly beginning about 28 days after vaccination.
In safety information released Wednesday on more than 6,700 trial participants, nearly 49% had pain at their injection site, 39% developed a headache after the shot, 38% were tired and 33% had muscle pain. Nearly all these symptoms were considered mild or moderate and resolved in one or two days.
Vaccine recipients over 60 were less likely than younger ones to suffer side effects, which is consistent with the other vaccines.
Nearly 20% of people in the active vaccine group took pain or fever medication in the week after their shot compared with 6% of those in the placebo group, mostly driven by vaccine recipients under 60.
People who received the active vaccine compared with placebo were slightly more likely to suffer from hives (five in the vaccine group and one in the placebo group), blood clots (15 versus 10) and ringing in their ears (six versus none), although it was unclear whether these symptoms were caused by the vaccine or simply coincidental.
In that subgroup, there were no more serious events that could be linked to the vaccine, the study found.
A total of 25 deaths were reported in the study, five in the vaccinated group and 20 who received a placebo. One serious allergic reaction was reported by a participant in the vaccinated group, probably related to the shot, but it was not classified as anaphylaxis.
Cases of Bell’s palsy, a type of facial paralysis, had been possibly associated with other COVID-19 vaccines. In the J&J vaccine trail, of four participants who came down with Bell’s palsy, half were in the vaccine group and half in the placebo group, so there was no indication the vaccine caused the condition.
Seven participants became pregnant after being vaccinated, four in the placebo group and three in the active vaccine group. Two pregnancies in the placebo group were intentionally ended, three ended in miscarriage or other problems (two in the active vaccine group, one in the placebo group) and two are ongoing.
A study in rabbits found no suggestion that the vaccine might be toxic to the mother or offspring in pregnancy.
The company plans several followup studies, including one in pregnant women, one in adolescents in Europe looking at health records and insurance claims of vaccinated people for safety and another focused on effectiveness. Vaccine providers must report any serious side effects from the vaccine to a national registry.
A Food and Drug Administration advisory committee will hold an all-day meeting Friday to review the data and is likely to give the Johnson & Johnson vaccine a thumbs-up, leading to an expected FDA authorization within the next few days.