Distribution of a third vaccine to combat COVID-19 has begun across the country, following federal authorization last week.
The federal Food and Drug Administration on February 27 granted emergency use authorization for a single-shot COVID-19 vaccine from Janssen, a division of Johnson & Johnson. The new vaccine, authorized for people age 18 and older, will expand the total supply and accelerate progress toward a return to normal life.
"To get control of the COVID-19 pandemic, stay ahead of worrisome viral mutations, and protect the American public, we must vaccinate as many Americans as we can as quickly as possible," National Institutes of Allergy and Infectious Diseases director Dr. Anthony Fauci said in a statement. "The Janssen vaccine provides yet another option to help achieve those goals."
The new vaccine, dubbed Ad26.COV2.S, uses an inactivated adenovirus — a common cold virus — that cannot replicate and cause illness itself. The weakened adenovirus delivers genetic blueprints for the spike protein the coronavirus uses to enter cells. The same platform is used for the company's approved Ebola virus vaccine and an HIV vaccine now being tested in two large trials.
Safe and effective
The FDA authorization was based on results from the Phase 3 ENSEMBLE trial, which was designed to test how well the vaccine prevents moderate or severe COVID-19.
The study enrolled more than 43,000 adults in the United States, Central and South America, and South Africa; they were randomly assigned to receive a single injection of the vaccine or a placebo. The trial included a diverse population. About 40% had underlying health conditions that raise the risk of severe COVID-19 and 1,218 participants were living with HIV.
Overall, a single dose of the vaccine was 66% effective. A total of 66 cases of moderate or severe COVID-19 occurred in the vaccine group versus 193 cases in the placebo group a month or more after vaccination. But the overall number hides some regional differences. Effectiveness rose to 72% in the United States but fell to 64% in South Africa and 68% in Brazil, where more transmissible coronavirus variants are circulating widely.
Across all regions, the vaccine was 85% effective at preventing severe or critical COVID-19. No one in the vaccine group was hospitalized or died from COVID-19 a month after vaccination, while there were 16 hospitalizations and seven deaths in the placebo group.
In general, the vaccine was effective regardless of demographics and underlying health conditions. Efficacy was lower, at 42%, for people over age 60 with underlying health conditions, but even in this high-risk group the vaccine prevented hospitalization and death.
What's more, the vaccine also reduces asymptomatic infection, which means it will lower the risk of transmission from people who have been vaccinated. In a subset of 2,650 people without symptoms who were tested for coronavirus antibodies, 18 vaccine recipients and 50 placebo recipients tested positive — a 66% reduction.
The vaccine was well tolerated with no notable safety concerns. The most common side effects were soreness at the injection site and flu-like symptoms such as headache, fatigue, and muscle aches. One case of anaphylaxis (severe allergic reaction) was reported.
Although the new vaccine appears less effective than the Pfizer-BioNTech and Moderna vaccines, which are 95% and 94% effective after two doses, respectively, it will offer a major public health benefit when it comes to increasing vaccine supply, easing pressure on hospitals, and reducing COVID-19 deaths. Experts stress that people should get whichever vaccine they are offered.
Johnson & Johnson only requested authorization for the single shot, but it is also testing a two-dose regimen that could prove more effective. If this happens, the FDA could amend its authorization and recipients could be given a second booster dose.
The Pfizer-BioNTech and Moderna vaccines are also quite effective after a single dose, but those companies only requested authorization for a double-dose regimen. However, some experts have argued that everyone should receive a first dose as soon as possible to gain partial immunity, delaying second doses until supplies are more plentiful.
Speeding vaccine rollout
In addition to requiring only a single dose, the new vaccine can be stored and transported at standard refrigerator temperatures and does not require super-cold freezers like the more delicate Pfizer-BioNTech vaccine. Therefore it is expected to be particularly useful in more remote areas and for harder-to-reach groups.
"The availability of another safe and effective vaccine that requires only one dose and that can be stored with only basic refrigeration opens new opportunities for delivery and expanded access for millions of people," Infectious Diseases Society of America president Dr. Barbara Alexander said in a statement.
Johnson & Johnson said it expects to provide enough doses to vaccinate 20 million people by the end of March and 100 million by the end of June. Governor Gavin Newsom wrote on Twitter that he expects California will get around 380,000 doses this week.
The latest authorization will help relieve supply shortages that have slowed the vaccine rollout. In San Francisco, mass vaccination sites at Moscone Center and City College had to temporarily suspend operations last month due to limited supply. The Coliseum site in Oakland, run by the Federal Emergency Management Agency, gets its supply directly from the federal government and does not draw on the state supply.
To date, nearly 162,000 San Franciscans — 22% of the population over age 16 — have received at least one vaccine dose and more than 69,000 are fully vaccinated, according to the San Francisco Department of Public Health's vaccine tracker.
San Francisco Health Director Dr. Grant Colfax, a gay man, said last month that the city has the capacity to administer upward of 10,000 vaccine doses per day. UCSF infectious disease expert Dr. George Rutherford told the San Francisco Chronicle that if the city vaccinates 5,000 new people per day, it should reach the estimated herd immunity threshold of 85% by the end of May. At that point, enough people will be immune — due to either vaccination or natural infection — that the virus will no longer be able to spread easily.
Help keep the Bay Area Reporter going in these tough times. To support local, independent, LGBTQ journalism, consider becoming a BAR member.