Both companies used a highly innovative and experimental approach to design their vaccines.
Moderna says in a press release today that it is a “big day” and they plan to request approval for the use of the vaccine in the coming weeks.
However, these data are still initial and the main questions remain unanswered.
How effective is the vaccine?
The trial involved 30,000 people in the United States, with half receiving two doses of the vaccine, four weeks apart. The rest received false injections.
The analysis was based on the first 95 volunteers to develop Covid-19 symptoms.
Only five of Covid’s cases occurred in people who received the vaccine, 90 were in people who received the fake treatment. The company says the vaccine is protecting 94.5% of people.
The data also shows that there were 11 serious cases of Covid in the trial, but none occurred in people who were immunized with the vaccine.
“The overall effectiveness was remarkable … it’s a big day,” Tal Zaks, the medical director of Moderna, told BBC News .
Dr. Stephen Hoge, the company’s president, said he “smiled from ear to ear for a minute” when the results arrived.
He told BBC News: “I don’t think any of us really expected the vaccine to be 94% effective in preventing Covid-19 disease, that was really an impressive finding.”
When will I get the vaccine?
It depends on where you are in the world and your age.
Moderna says it will apply to US regulators in the coming weeks. The expectation is to have 20 million doses available in the country.
The company expects to have up to a billion doses available for use worldwide next year and plans to seek approval in other countries as well.
What don’t we know yet?
We don’t know how long immunity will last, as volunteers will have to be accompanied for much longer before we know it.
There is evidence that the vaccine offers some protection in older age groups, who are at the greatest risk of dying from Covid, but there are no complete data.
Zaks told the BBC that his data so far suggests that the vaccine “does not appear to lose its potency” with the age of the volunteers.
And we’re not sure if the vaccine just prevents people from becoming seriously ill or if it also prevents them from spreading the virus.
All of these questions will affect how the coronavirus vaccine is used.
Is the vaccine safe?
No significant safety concerns have been reported, but nothing, not even aspirin, is 100% safe.
Short-term fatigue, headache and pain at the injection site have been reported in some patients.
“These effects are what we would expect from a vaccine that is working and inducing a good immune response,” said Professor Peter Openshaw of Imperial College London.
How does this compare to the Pfizer vaccine?
Both vaccines use the same approach of injecting part of the virus’s genetic code to elicit an immune response in the human body.
The preliminary data we’ve seen so far is very similar – about 90% protection for the Pfizer / BioNTech vaccine and about 95% for Moderna.
However, both clinical trials are still in progress and the final numbers may change.
Moderna’s vaccine seems to be easier to store, as it remains stable at less than 20ºC for up to six months and can be kept in a regular refrigerator for up to one month.
The Pfizer vaccine needs to be stored in an ultra-cold freezer at around minus 75ºC, but it can be kept in the refrigerator for five days.
How it works?
Moderna developed an “RNA vaccine” which means that part of the coronavirus genetic code is injected into the body.
This leads to the production of viral proteins, but not the complete virus, which is sufficient to train the immune system to attack the real virus.
The vaccine trains the body to produce antibodies and T cells to fight the coronavirus.