A clinical trial evaluating a vaccine designed to protect against the new coronavirus began on Monday in Seattle, US health officials said.

“The open-label trial will enroll 45 healthy adult volunteers ages 18 to 55 years over approximately 6 weeks,” the US National Institutes of Health (NIH) said in a statement.

“The first participant received the investigational vaccine today.”

The trial which is taking place at the Kaiser Permanente Washington Health Research Institute in Seattle, the officials said.

It will take a year to 18 months to fully validate any potential vaccine.

There is no chance participants could get infected from the shots, because they don’t contain the virus itself. The goal is purely to check that the vaccines show no worrisome side effects, setting the stage for larger tests.

Dozens of research groups around the world are racing to create a vaccine as Covid-19 cases continue to grow. Importantly, they’re pursuing different types of vaccines — shots developed from new technologies that not only are faster to produce than traditional inoculations but might prove more potent.

Some researchers even aim for temporary vaccines, such as shots that might guard people’s health a month or two at a time while longer-lasting protection is developed.

For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia.

The worldwide outbreak has sickened more than 175,536 people and left more than 7,007 dead. The death toll in the US is 68, while infections neared 3,927.