The Food and Drug Administration’s independent experts on vaccines recommended the authorization of the Johnson & Johnson COVID-19 vaccine in a unanimous 22-0 vote Friday, setting in motion the probable authorization of a third vaccine within days.
The influential Vaccines and Related Biologics Advisory Committee, or VRBPAC, recommended the vaccine after a relatively frictionless daylong meeting.
The shot could be the first “viral vector” vaccine in the U.S. arsenal; the vaccine uses a non-replicating and harmless adenovirus.
The vaccine provides 66 percent protection against moderate COVID-19 and 85 percent efficacy against severe disease 28 days after vaccination, the FDA said, meeting the threshold the agency set for any emergency use authorization of a COVID-19 vaccine, according to documents it prepared ahead of the meeting.
About 99.6 percent of participants in the 40,000-person clinical trial did not experience serious side effects. Thousands of volunteers did experience mild ones that can indicate the vaccine is working, like site pain, headache and fatigue.
The FDA is expected to make a final determination as soon as this weekend. Johnson & Johnson submitted its application for an emergency use authorization on Feb. 4.
“We really are looking forward with very positive anticipation to the final determination of the VRBPAC and the FDA concerning the Johnson & Johnson or Janssen vaccine,” National Institutes of Health top official Anthony Fauci said Friday afternoon. “This should be forthcoming, hopefully within the next day or two, together with the recommendations about how it is to be utilized."
The one-dose shot can be stored at refrigerator temperatures for three months, which means it will be simpler to store and administer than the two previously authorized vaccines.
Less than 4 million doses will be ready at the time of the emergency use authorization, fewer than the 10 million originally projected, although the company projects that to grow to a total of 20 million by the end of March. Vaccine jurisdictions do not know how many doses they will receive if the vaccine is authorized.
The news comes at the same time as the White House and the Centers for Disease Control and Prevention sounded the alarm about viral variants of concern gaining ground, likely diminishing the impact of the new vaccine on national caseload totals.
Vaccines do not appear to provide as robust protection against variants with a certain mutation to the spike protein, acknowledged Adam MacNeil, an epidemiologist with the Special Pathogens Branch within CDC. That mutation is found on the variant that originated in South Africa and a variant from Brazil.
Vaccines may need to be updated every year like with the annual flu vaccine, or every five years, but that is still unclear.
“The fundamental question is how is this virus going to behave?” he said.
Conducting clinical trials at a time when variants were dominant in South Africa and Brazil appeared to affect the vaccine’s efficacy.
The Johnson & Johnson vaccine was tested in eight countries, with 44 percent of participants in the U.S., 41 percent of participants in Latin America, and 15 percent of participants in South Africa. After two weeks, the vaccine was 74 percent effective in the U.S., 52 percent effective in South Africa, and 62 percent effective in Brazil. But the vaccine was highly effective in warding off severe or critical cases in all three countries, especially after a month.
The vaccine was tested in a racially diverse population, the company told the committee. People with at least one comorbid condition that can worsen COVID-19 made up about 40 percent of volunteers. People 60 years old or older made up 30 percent of volunteers, and people younger than 40 years old only made up 20 percent of volunteers.
Many vaccines generate a weaker immune response in older adults, and the Johnson & Johnson vaccine is no exception. Some committee members were concerned that the vaccine was less effective in preventing moderate and severe and critical cases in people with comorbidities, especially people over the age of 60.
Other committee members expressed concern that people could develop immunity to the viral vector, which could decrease the effectiveness of booster shots.
One committee member pointed out the difficulty of comparing the efficacy of the Johnson & Johnson vaccine with the Moderna and Pfizer vaccines. The Johnson & Johnson vaccine was tested against viral variants while the earlier mRNA vaccines were not.
Experts worry that people will get hung up on the diminished efficacy of the Johnson & Johnson vaccine against very mild cases. Each of the three vaccines showed 100 percent efficacy against deaths, though the data on mortality is limited.
“All of the vaccines seem to be equally effective at preventing very severe disease, intensive care needs and deaths. It’s a difficult question, but has the FDA considered that perhaps different endpoints should be considered?” said Cody Meissner, a pediatric infectious diseases expert at Tufts University.
Maria Allende, FDA medical officer, said the FDA would continue to monitor the duration of efficacy and efficacy against new strains.
The company has already begun testing a two-dose regimen in smaller clinical trials, which could confer more durable protection, including against viral variants. But the company made a judgment last year that the one-dose shot could curb hospitalizations and deaths more quickly.
The VRBPAC has grilled the FDA in prior meetings on why it did not zero in on preventing hospitalizations and deaths in its guidance to drugmakers. The FDA has stressed that severe cases are more rare and would take longer to observe than mild ones, and that the pandemic is urgent.
Emergency use authorizations are granted in national emergencies when the benefits of a product to treat a life-threatening disease outweigh the risks. But the FDA set out more stringent standards of safety and efficacy and manufacturing consistency in October 2020, and experts say the COVID-19 vaccine EUAs closely resemble the process of a full approval.