As per interim results published on medical website medRxiv, Johnson and Johnson's experimental vaccine called Ad26.COV2.S can stand tall versus Moderna Inc and Pfizer Inc's work, reported Reuters.J&J's vaccine produced a strong immune system in the early-to-mid stage clinical trial according to the results published on Friday. Owing to the Ad26.COV2.S' single shot approach against its competitors' two-dose assumption, the vaccine might simplify the distribution process.Johnson and Johnson went public with this vaccine in July and with significant backing from the US Government, they conducted a trial on 1,000 healthy adults. The American multinational corporation expects results of their phase 3 trial by the end of the year or early next year. The phase 3 trial, involving 60,000 people, started on Wednesday.However, certain questions pertaining to the vaccine's ability to protect the elderly population from the virus. Researchers, including those from J&J’s unit Janssen Pharmaceuticals, said 98% of participants with data available for the interim analysis had neutralising antibodies, which defend cells from pathogens, 29 days after vaccination. The immune response results were available from only a small number of people - 15 participants - over 65 years old, limiting the interpretation. The results, released on the medical website medRxiv, have not been peer-reviewed.For now, the results justify why more studies are needed in larger numbers to look for serious adverse effects, Dr Barry Bloom, a professor at Harvard TH Chan School of Public Health who was not involved in the J&J trial, told Reuters.“Overall, the vaccine is doing what you would expect it to do if you were to move it to Phase 3 trials,” Bloom said.