Tests have shown that the vaccine promotes the creation of protective antibodies.
On the global front, Dr Anthony Fauci said that 250,000 people have registered on the National Institute of Heath's website to take part in experimental vaccine trials.
More than 100 possible vaccines are being developed around the world to try to stop the COVID-19 pandemic.
The Philippines plans to buy 40 million doses worth $400 million for 20 million people, around a fifth of the country's 107 million population, the country's Finance Secretary Carlos Dominguez said.
Mike Ryan, executive director at the World Health Organisation, said earlier this months that "there is a long way to go" before the world gets its first approved vaccine. All 20 animals that received the placebo developed high levels of virus in their lungs and nasal swabs.
Six weeks after immunization, all animals were exposed to SARS-CoV-2. Around the same time, the company will start a parallel phase 3 study testing a two-shot regimen of the vaccine, Stoffels said.
"We look forward to the results of the clinical trials that will determine the safety and immunogenicity, and ultimately the efficacy, of the Ad26.COV2.S vaccine in humans", the authors wrote.
Russian Federation is behind other developing vaccines that are in the third phase of their trials, as they will complete their second phase on August 3, and the third phase will be running when the medical workers are vaccinated.
"We are searching for more volunteers and if any one who is healthy, class 12th pass and between 18 and 55 years of age wants to become volunteer for clinical trials and join hands against COVID-19 can contact us on phone numbers - 8303028051 and 6388214084", Mr Chaturvedi said.
"We have started human clinical trials of Bharat Biotech's vaccine and soon the trial of Zydus Cadila vaccine will be started", Chaturvedi added.