The Moderna coronavirus vaccine is set to be rolled out in England from Tuesday.
It comes after the first doses were delivered in Wales and Scotland last week and follows the rollout of the Pfizer and AstraZeneca vaccines, which began in December and January respectively.
Adults in their late 40s in England are set to be offered a first dose of a coronavirus vaccine this week.
– How effective is it against coronavirus?
The phase three results suggested vaccine efficacy against the disease was 94.1%, and vaccine efficacy against severe Covid-19 was 100%.
More than 30,000 people in the US took part in the trial, from a wide range of age groups and ethnic backgrounds.
Two doses were given 28 days apart so researchers could evaluate safety and any reaction to the vaccine.
The analysis was based on 196 cases, of which 185 cases of Covid-19 were observed in the placebo group versus 11 cases observed in the active vaccine group.
Moderna also released data relating to severe cases.
All 30 severe cases occurred in the placebo group and none in the group which had received the vaccine, known as mRNA-1273.
– Who developed the vaccine?
Moderna is a US pharmaceutical and biotechnology company with its headquarters in Cambridge, Massachusetts.
The vaccine received funding from two US federal agencies – the National Institute of Allergy and Infectious Diseases (NIAID) and the Biomedical Advanced Research and Development Authority (Barda).
Dolly Parton is credited with helping fund the jab after donating one million dollars (about £716,000) to Vanderbilt University Medical Centre in Nashville, Tennessee, which participated in the research.
To the tune of Jolene, Parton sang: “Vaccine, vaccine, vaccine, vaccine, I’m begging of you, please don’t hesitate. Vaccine, vaccine, vaccine, vaccine, because once you’re dead, then that’s a bit too late.”
– How many doses of Moderna does the UK have?
The Government has bought 17 million doses – enough to vaccinate about 8.5 million people.
A benefit of the Moderna vaccine is that it can be safely stored at temperatures of around minus 20C (minus 4F) – achievable in a standard pharmaceutical fridge – making distribution much easier.
The Pfizer vaccine on the other hand has to be stored at minus 70C (minus 94F) and is only stable for a short period at higher temperatures, making it difficult to administer away from hospital hubs.
The Moderna jab can be stored for about 30 days before use.
– How does the vaccine work?
The Moderna jab is a messenger RNA (mRNA) vaccine.
Conventional vaccines are produced using weakened forms of the virus, but mRNAs use only the virus’s genetic code.
An mRNA vaccine is injected into the body, where it enters cells and tells them to create antigens.
These antigens are recognised by the immune system and prepare it to fight coronavirus.
No actual virus is needed to create an mRNA vaccine.
This means the rate at which the vaccine can be produced is accelerated.
– Is the vaccine safe?
Moderna said the vaccine was generally well tolerated, with no serious safety concerns identified.
Severe events after the first dose included injection-site pain, and after the second dose included fatigue, myalgia (muscle pain), arthralgia (joint pain), headache, other pain and redness at the injection site.
But these were generally short-lived.
– Is the Moderna vaccine effective against variants?
In late January, the company behind the vaccine said it was effective against both the strain first detected in south east England and the mutation which first emerged in South Africa.
Moderna said laboratory tests found no significant impact on antibodies against the UK variant relative to prior variants.
While there was a six-fold reduction in neutralising antibodies produced against the South African variant, the levels remained above those that are expected to be protective, Moderna said.
– What stage is the Moderna rollout at in each of the four UK nations?
People in Wales got their first doses of the vaccine from Wednesday last week, at the West Wales General Hospital in Carmarthen.
Scotland’s clinical director Professor Jason Leitch said the vaccine had been given to patients at the Hydro in Glasgow last week.
The rollout will begin in England on Tuesday.
It has not been confirmed when the rollout of Moderna will begin in Northern Ireland.
-Will there be any side effects?
Like all medicines, the vaccine can cause possible side effects – but not everyone gets them.
Common side effects with the Moderna vaccine can include flu-like symptoms and pain or swelling at the injection site, most can be treated by paracetamol.