Researchers, including those from J&J’s unit Janssen Pharmaceuticals, said 98% of participants with data available for the interim analysis had neutralizing antibodies, which defend cells from pathogens, 29 days after vaccination.
However, immune response results were available from only a small number of people - 15 participants - over 65 years old, limiting the interpretation.
In participants older than 65, the rate of adverse reactions such as fatigue and muscle aches was 36%, much lower than the 64% seen in younger participants, the results showed, suggesting the immune response in older people may not be as strong.
