Scientists around the globe are racing to develop a vaccine against Covid-19, with more than 140 candidate vaccines now tracked by the World Health Organization.

Of these, some few have entered clinical trials. Among these are two vaccines made by US drug companies Moderna and Pfizer.

Scientists are hoping to develop a coronavirus vaccine within 12 to 18 months, although vaccines normally require years of testing and additional time to produce at scale.

Before being certified by the WHO to be safe for general use, vaccines undergo a number of stages of testing which include pre-clinical stage (where researchers give the vaccine to animals to see if it triggers an immune response), and the clinical stage (research investigations in which people volunteer to be given the vaccine that is being tested.

Clinical trials happen in a three-phase process. During Phase one, small groups of people receive the trial vaccine.

In phase two, the clinical study is expanded and vaccines are given to people who have characteristics (such as age and physical health) similar to those for whom the new vaccine is intended.

In Phase III, the vaccine is given to thousands of people and tested for efficacy and safety.

About 5 Covid-19 vaccines have entered the 3rd phase of clinical trials.

Commenting on the ongoing efforts of finding a vaccine against Covid-19, Dr. Daniel Ngamije, Rwanda’s Minister of Health commended the level at which the research has reached and expressed optimism for good results in the future.

"We hope that in the next 6 months, we can get a vaccine that will be approved by the WHO,” he said.

The development of a successful vaccine is one of the sure ways of stopping the pandemic.

According to the Johns Hopkins Coronavirus Resource Centre, there were 17,622,478 confirmed cases of Covid-19 globally on Saturday evening.