A new vaccine that protects against Covid-19 is almost 95 per cent effective.

The early data from United States company Moderna come hot on the heels of similar results from Pfizer, which reportedly is 90 per cent effective.

How trial was conducted

The trial involved 30,000 people in the U.S., with half given dummy injections and the other half being given two doses of the vaccine, four weeks apart.

The analysis was based on the first 95 to develop Covid-19 symptoms.

Only five of the Covid-19 cases were in people given the vaccine, 90 were in those given the dummy treatment.

The company says the vaccine is protecting 94.5 per cent of people.

The data also showed there were 11 cases of severe Covid19 in the trial, but none happened in people who were immunised.

1 billion doses by next year

Moderna says it will apply to regulators in the U.S. in the coming weeks and expects to have 20 million doses available in the country.

The company hopes to have up to one billion doses available for use around the world in 2021.

Approval in other countries will be sought too.

What is still unknown?

It is still not known how long immunity will last.

Volunteers will have to be followed for much longer.

There are hints the vaccine offers some protection in older age groups, who are most at risk of dying from Covid-19.

Is it safe

Short-lived fatigue, headache and pain were reported after the injection in some patients, but these side effects are to be expected of a vaccine that works.

How does vaccine work?

Moderna has developed an "RNA vaccine".

Part of the coronavirus's genetic code is injected into the body.

Viral proteins are made in the body, but not the whole virus, which is enough to train the immune system to attack.

It should train the body to make both antibodies, and another part of the immune system called T-cells to fight the coronavirus.

Pfizer and Moderna used an experimental approach to designing their vaccines.

Both results are adding to the growing confidence that vaccines can help end the pandemic.

Top photo via Moderna

We deliver more stories to you on LinkedIn