Given that it takes several years to develop an effective vaccine for a viral disease, world leading pharmaceutical companies and universities are in the race to develop a COVID-19 vaccine because the pandemic has infected almost five million people and killed almost 600,000 within five months.

The vaccine was found to elicit neutralising antibodies, which peaked at day 28 post-vaccination, while rapid specific T-cell responses peaked at day 14 after vaccination.

As per the study, about 81% of all the participants (83% in the low-dose group, 83% in the middle-dose group and 75% in the high-dose group) showed at least one adverse reaction to the vaccine within the first seven days. Some systemic adverse reactions noted in all patients were fever, muscle pain and headache.

Most of the people dosed with the vaccine had immune responses, although their levels of antibodies thought to neutralize the virus were relatively low.

A woman holds a small bottle labbeled with a "Vaccine COVID-19" sticker and a medical syringe in this illustration taken April 10, 2020.

Presidential Spokesperson Harry Roque said the Department of Science and Technology (DOST) has been directed to lead the preparations for such clinical studies, including identifying the study sites and researchers to be involved in the vaccine trials as well as getting the approval of the ethics board. Ad5-nCoV is built upon CanSino BIO's adenovirus-based viral vector vaccine technology platform, which has also been applied to develop a vaccine against Ebola.

Developed in Thailand the vaccine "Wuhan" infection COVID-19 prepare for mass use not earlier than in half a year.

More than 100 vaccine candidates against SARS-CoV-2 are in development worldwide, with about 12 in human testing created to mainly evaluate safety.

Dalhousie says Canada's first clinical trial for a potential vaccine will start with fewer than 100 people between the ages of 18 and 55.

The two research centers "can initiate and strengthen local vaccine development", according to the IATF, which already approved the recommendations on Friday.

The vaccine uses a weakened common cold virus called adenovirus, which infects human cells easily but does not cause a disease. The vaccine was made with a certain mutation of a virus, named Ad5, which genetically modifies the protein structure once injected inside the cell.

The vaccine also triggered a T-cell response in a majority of the volunteers. One participant who was given the higher dose vaccine reported severe fever, along with severe symptoms of fatigue, shortness of breath and muscle pain.

In these people, "their immune systems will essentially rear up and blunt the effect of the vaccine", said Dr. Kirsten Lyke, a vaccinologist at the University of Maryland who is leading another coronavirus vaccine trial. Results from preclinical animal studies of the vaccine showed that "Ad5-nCoV" can induce a strong immune response in animal models, demonstrating a good safety profile.

Aside from the vaccine efforts in China, researchers in Britain and the United States are also pushing forward similar trials.

The vaccine will continue to be trialled on monkeys for three months in the next phase of the process.