Miami (AFP)

Heather Lieberman hopes to develop immunity. Sandra Rodriguez, she wants to advance research. The two women volunteered for clinical trials of experimental anti-Covid vaccines in Florida, the epicenter of the epidemic in the United States.

"I want to help and help write history," says Sandra Rodriguez, a 63-year-old teacher, at a clinic near Miami where a nurse is preparing to give her an injection.

"I want to do good and I know I do. So I have no hesitation," she insists.

The third and final phase of clinical trials requires thousands of participants to verify the efficacy and safety of experimental vaccines.

Hard hit by the pandemic, with more than half a million recorded cases and nearly 9,000 deaths, Florida has no shortage of volunteers.

The private organization Research Centers of America (RCA), located in the city of Hollywood, about forty kilometers north of Miami, is testing a total of six experimental vaccines against Covid-19, two of which are in phase 3.

Volunteers go there one by one, by appointment. They are examined by a doctor, sign a form and receive their injection. It is either an experimental vaccine or a placebo: a methodology necessary in order to be able to establish comparisons.

They are then asked to wait about two hours before returning home, after doctors have made sure they do not have any side effects.

"Everything is going well, none of the patients we have vaccinated so far have had any complications," says Nelia Sanchez-Crespo, doctor and researcher at the RCA clinical research center.

Volunteers are "pouring in," she notes. "They are very motivated. People are more eager than usual to participate in these trials because they really want a vaccine to be available as soon as possible."

The prospect of developing immunity to the novel coronavirus also motivated Heather Lieberman.

"It's worth a try, there aren't really any other options. You can't live in a vacuum," says the 28-year-old, crossing her fingers not to receive the placebo.

- Open to everyone -

RCA tests a different experimental vaccine every day. Today: mRNA-1273 jointly developed by biotech Moderna and the US National Institutes of Health (NIH), whose phase 3 testing began on July 27 across the country.

Each experimental vaccine will be injected to 30,000 people, in dozens of American centers, most of them in Florida, California and Texas, the most affected states.

Volunteers register online before being contacted by the clinic. Everyone can participate.

"Each test looks at something different. We definitely want different profiles," says Nelia Sanchez-Crespo, who hopes to welcome several hundred volunteers to RCA each week.

"Healthy people, emergency responders, doctors, nurses, firefighters, people who work in airports or restaurants," she explains. "It's very important. They are in contact with a lot of people."

"But also risk profiles due to medical problems such as diabetes, asthma or chronic obstructive pulmonary disease", continues the researcher.

Two Western anti-Covid vaccine projects, in addition to that of Moderna / NIH, are also in the final phase of clinical trials: those of the Oxford / AstraZeneca and Pfizer / BioNTech alliances.

Two others are at the same stage in China, while Russia announced this week that it had developed a vaccine giving "lasting immunity", dubbed Sputnik V.

An announcement greeted with skepticism within the Western scientific community, the Russian vaccine having not yet been submitted to phase 3 clinical trials.

The United States has already invested more than $ 10 billion in total in six vaccine projects and signed contracts guaranteeing the delivery of hundreds of millions of doses in case of conclusive trials.

© 2020 AFP