Background to the Moderna vaccine
The UK approved the Moderna vaccine on 8 January 2021 and began using it on 7 April 2021 with the first doses rolled out in Wales.
Scotland took delivery of its first batch on 5 April 2021 and England is expecting deliveries from mid-April.
As with the Pfizer and AstraZeneca jabs the Moderna vaccine is given in two doses, four to twelve weeks apart.
The UK currently has a total of 17 million doses on order. (1)
The EU approved it on 6 January 2021 and has ordered 160 million doses. (2)
Moderna is an American company and, under an executive order signed by then president Trump in December 2020, its export outside of the US was banned. (3)
Although the order is still in place under President Biden, Moderna has partnered with Lonza, a Swiss biotechnology company with facilities in Europe, North America and South Asia. The two companies have agreed a ten year plan to produce the vaccine across Lonza’s plants and supply it worldwide. They hope to supply up to 1 billion doses of vaccine per year worldwide. (4) (5)
The Moderna vaccine is similar to the Pfizer one. (Click here to read more on the Pfizer vaccine.)
Both are mRNA vaccines which means they work by transporting a small part of the virus’s genetic code into the body. Other vaccines also work by carrying part of the virus’s genetic code but the difference with the mRNA vaccines is that no actual virus is needed to create them, scientists have been able to manufacture the genetic code in the laboratory. Vaccines such as AstraZeneca’s and Russia’s Sputnik extract the code from the virus itself and then use a small part of it in their vaccines.
Unlike the Pfizer vaccine which has to be stored at -70’C, Moderna’s can be stored at -20’C and can be transferred to a normal fridge for up to one month prior to using. (The Pfizer vaccine can only be transferred to a fridge for five days maximum prior to using.) Whilst this is an advantage over Pfizer's, the Moderna vaccine still requires initial specialist medical refrigeration/freezing and this could limit its use in countries where there are no such storage facilities.
The Moderna Trial
The trial data concluded that the vaccine was 94% effective overall in preventing illness although this declined with age with the rate for those over 65 years dropping to 84%.
However, the vaccine was 100% effective at preventing severe disease. None of the vaccinated individuals who still went on to contract COVID-19 became seriously ill with it or needed to be hospitalised.
The trial was carried out in the US and recruited 30,351 participants aged 18 and older.
15,185 people received at least one dose of the vaccine and 15,166 received a placebo injection.
75% of the participants were in the 18 to 64 age bracket and 25% were age 65 and over.
47.4% of participants were female and 52.6% were male.
79.5% were White, 9.7% were African American, 4.6% were Asian, and 6.2% were classed as “Other”.
98% of all vaccine recipients received a second dose of vaccine 25 days to 35 days
after dose 1.
There were 11 cases of COVID-19 in the vaccinated arm of the trial and 185 in the placebo arm.
None of the vaccinated arm had serious COVID-19 but in the placebo group 30 of the 185 cases were seriously ill with nine requiring hospitalisation, two on intensive care units. (6)
Common Side effects
Pain at the injection site - 92% of participants
Fatigue -70% of participants
Headache - 64.7% of participants
Myalgia (muscle pain) - 61.5% of participants
Arthralgia (joint pain) - 46.4% of participants
Chills - 45.4% of participants
Nausea and/or vomiting - 23% of participants
Axillary (armpit) swelling and/or tenderness - 19.8% of participants
Fever - 15.5% of participants
Injection site swelling - 14.7% of participants
Injection site redness - 10% of participants
Most side effects were reported as mild or moderate and resolved 2 to 3 days after vaccination.
Side effects were more common in the 18 – 64 age group than the older, 65 years and over, group.
Side effects were more common after the second dose of vaccine than the first. (7)
Serious Side Effects
Anaphylaxis has been reported with the Moderna vaccine but is rare with an incidence of 2 to 3 cases for every 1 million vaccinations.
Appropriate medical treatment should always be available in case of an anaphylactic reaction and this is why recipients are asked to remain for 15 minutes observation post vaccination.
Four people experienced a Bell’s Palsy (facial paralysis) post injection, three had received the vaccine and one the placebo injection.
Two vaccine recipients had severe facial swelling in the 24 to 48 hours after vaccination. Both these people had a history of injection of dermatological fillers. (8) (9)
Post vaccination
As more and more people are vaccinated it is important to remember that until the pandemic is over we need to keep practising social distancing, wearing a face mask and washing our hands frequently.
We do not yet know the extent to which any of the vaccines are preventing the spread of COVID-19 between people. It is possible that a vaccinated individual could still pass the virus on to an unvaccinated person....and that unvaccinated person could be the one who becomes seriously ill and needs an ITU bed or dies.
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