How does the Moderna Covid-19 vaccine work?

Trials of the Moderna coronavirus vaccine suggest it is 94% effective against Covid-19.

Furthermore, no person who was vaccinated with the jab, known as mRNA-1273, developed severe coronavirus.

US firm Moderna has said its trial results indicate the jab is generally well tolerated with no serious safety concerns.

– How does the Moderna vaccine work?

The Moderna vaccine works in a very similar way to the jab from Pfizer/BioNTech.

How the RNA vaccine would work
How the RNA vaccine would work

Coronavirus is studded with “spike proteins” that it uses to enter human cells. Covid-19 vaccines target this spike protein.

The Moderna and Pfizer vaccines use synthetic messenger RNA (mRNA), a genetic material that contains information about the spike protein.

The vaccines provide the body with instructions to produce a small amount of this protein which, once detected by the immune system, leads to a protective antibody response.

Moderna’s vaccine does not require the same ultracold storage as Pfizer’s and can remain stable at normal fridge temperature for 30 days.

– How effective is it?

Trials on more than 30,000 people in the US have shown the Moderna jab to be 94% effective in preventing coronavirus.

While this efficacy may drop over time, scientists have said the vaccine should protect against around nine in 10 cases of Covid-19.

Moderna has not identified any significant safety concerns and its vaccine has been approved for use in the US.

– What about antibodies and T-cells?

The Pfizer, AstraZeneca and Moderna vaccines have been shown to provoke both an antibody and T-cell response.

Antibodies are proteins that bind to the body’s foreign invaders and tell the immune system that it needs to take action.

T-cells are a type of white blood cell which hunt down infected cells in the body and destroy them.

Nearly all effective vaccines induce both an antibody and a T-cell response.

– When will the Moderna vaccine arrive in the UK?

The Government has signed a deal for 17 million doses of the Moderna vaccine for the UK.

Covid-19 vaccine: order of priority
Covid-19 vaccine: order of priority

That is enough for around 8.5 million people, who will each receive two doses of the vaccine.

According to the Government, Moderna is currently scaling up its European supply chain which means these doses would become available in the UK in the spring.

– Can this vaccine help the elderly?

There have been concerns that a Covid-19 vaccine will not work as well on elderly people, much like the annual flu jab.

But data from Moderna suggests the jab is highly effective in preventing people getting ill and works across all age groups, including the elderly.

The Pfizer and AstraZeneca jabs have also been shown to work effectively in the elderly.