Early results from the phase 1/2a clinical trial for Johnson & Johnson's single-shot COVID-19 vaccine reveal it was tolerated well and elicited a strong immune response.
The drugmaker tested two dosages of the vaccine, finding 99 percent of trial participants ages 18 to 55 developed antibodies to fight the novel coronavirus. Complete immune response data for the group of participants age 65 and older was not available at the time the company issued the early results, but Johnson & Johnson said the responses were similar across all age groups studied.
The analysis also found that most of the side effects the vaccine caused, such as fatigue, fever, headaches, body aches and injection-site discomfort, were resolved after a couple days.
The early results were posted on Sept. 25 on the pre-print server medRxiv, and Johnson & Johnson promised to publish more results once the complete data for the phase 1/2a trial becomes available.
Johnson & Johnson is using the same technology for its COVID-19 vaccine as it did when it created its Ebola, Zika, HIV and RSV vaccine candidates. The candidate uses an adenovirus, which creates coronavirus proteins within the body that could prepare the immune system to fend off COVID-19. Adenovirus vaccines do not need to be stored in frozen settings, unlike most of the other vaccines in testing phases across the U.S.
The company began phase 3 testing for the candidate Sept. 23, becoming the fourth drugmaker in the U.S. to do so. The trial will test the shot's effectiveness in preventing COVID-19 against a placebo and include 60,000 participants in the U.S., Mexico, Argentina, Brazil, Chile, Colombia, Peru and South Africa.