People and governments world over are insisting on precautions to curb spread of Covid-19, in the effort for the same first human trial of vaccine against the new coronavirus has begun in Seattle, U.S. Here are the details:

In fight against coronavirus, people and government world over are taking as many precautions as possible. In Paris, people were seen standing at distance in queues while in New York, restaurants limit to takeout and delivery; United Kingdom closes down theatres to restrict mass gatherings.

President Donald Trump has urged Americans to halt most social activities for 15 days and not congregate in groups larger than 10 people in a newly aggressive effort to reduce the spread of the coronavirus in the United States.

Announcing new guidelines from his coronavirus task force, the president said people should avoid discretionary travel and not go to bars, restaurants, food courts or gyms.

The Republican president said he was focused on addressing the health crisis and that the economy would get better once that was in line.

Trump said the worst of the virus could be over by July, August or later. He called it an invisible enemy.

Meanwhile, in a major development, the first human trial to evaluate a candidate vaccine against coronavirus disease has begun in Seattle. President Trump also said that anti-viral therapies and other treatments are also in pipeline. The open-label trial will enroll 45 healthy adult volunteers’ ages 18 to 55 years over approximately 6 weeks. The first participant has already received the investigational vaccine.

The Seattle trial will study the impact of different doses delivered by intramuscular injection in the upper arm, with participants monitored for side-effects like soreness or fever.

Coronaviruses are spherical and have spikes protruding from their surface, giving them a crown-like appearance. The spike binds to human cells, allowing the virus to gain entry.

Injecting human tissue with the spike's messenger RNA makes it grow inside the body, thereby eliciting an immune response without having actually infected a person with the full-blown virus.