USA will test vaccines on more than 100,000 people starting in July

Fauci had earlier said that a vaccine to treat Covid-19 could be ready for distribution within 12 to 18 months.

Researchers are also accelerating development of the vaccine candidate by simultaneously investing in multiple stages of development that could prove to be useless if the vaccine ends up not being effective or safe, Fauci said.

Peter Hotez, who is developing a vaccine at the National School of Tropical Medicine at Baylor College of Medicine, added: "It's not surprising a significant percentage of Americans are not going to take the vaccine because of the bad messaging we've had, the absence of a communication plan around the vaccine and this very aggressive anti-vaccine movement".

The data will then be shared among the +5 companies that will take part.

He went on to explain that a vaccine should train the immune system to produce different types of antibodies. The vaccine has mRNA instructions for building the coronavirus's spike protein.

For the quickest response, the vaccines will be tested in healthcare workers and communities where the virus is still spreading to show if they reduced new cases of COVID-19.

The 108 participants (51% male, 49% female with a mean age of 36.3 years) were split into three groups, each one given the low dose (n=36), middle dose (n=36), or high dose (n=36) of the vaccine.

"As it was a first-in-human study of the adenovirus type-5 vectored COVID-19 vaccine, it was not created to measure the vaccine efficacy", they write.

All doses of vaccination triggered some level of immune response within two weeks. These antibodies can bind to the coronavirus but do not necessarily attack it.

'The one thing not we're not seeing is a really high neutralizing antibody titer, ' he told DailyMail.com. The most common side effects - described as "mild" and "moderate" - were pain at the injection site, fever, fatigue and headache.

Approximately 39 per cent of those vaccinated experienced headaches while 17 per cent reported muscle pain.

Any vaccine will be met by massive global demand requiring billions of doses and a total shift in approach to how vaccines are typically developed. However these adverse reactions persisted for less than 48 hours, the study noted.

However, this can not be considered as kind of the vaccine testing, Gintsburg noted.

Between 100,000 and 150,000 people may be enrolled in the studies, said Dr. Larry Corey, a vaccine expert at Fred Hutchinson Cancer Center in Seattle, who is helping design the trials.

The trial also had a small sample size, relatively short duration of study, and no control group, which would have allowed scientists to compare the volunteers to those who did not receive the vaccine.

Thailand announced on Wednesday that it was developing a vaccine - one of at least 100 potential vaccines in the works worldwide - and hoped to have it into production by next year https://www.reuters.com/article/us-health-coronavirus-thailand/thailand-says-it-expects-coronavirus-vaccine-next-year-after-tests-in-mice-idUSKBN22W0I8.

The phase-2 trial will be a randomised, double-blinded and placebo-controlled trial.