The chief infectious pathologist in the United States on Monday hailed the early results of Moderna’s Covid-19 vaccine trial as “amazingly impressive,” and called the results a sure confirmation of the experimental mRNA technology that some have questioned.
“I have to admit that I would have been satisfied with 70% or 75% at most,” he told AFP.
“The idea that we have a vaccine that is 94.5% effective is an amazingly cool idea. It’s really an amazing result. I don’t think anyone expected it would be that good.”
Fauci leads the National Institutes of Allergy and Infectious Diseases (NIAID), which began developing a vaccine with the US biotechnology company in January, shortly after China shared the genetic sequence of the novel coronavirus.
The vaccine is based on a relatively new technology that uses a synthetic version of a molecule called “messenger RNA” to penetrate human cells and effectively transform them into vaccine factories.
No vaccine based on this platform has been approved.
“There have been many people who have reservations about using something that has not been tried and true over the years; in fact, some people even criticize us for it,” Fauci said.
On Monday, Moderna and NIAID announced their preliminary results based on 95 of the 30,000 volunteers recruited who contracted Covid-19 disease.
Of the 95, 90 were in the trial placebo group, and five were in the group that received the drug, called mRNA-1273, resulting in an efficacy rate of 94.5%.
Fauci noted that some have questioned whether the vaccine would prevent severe forms of Covid-19, not just mild or moderate cases – and this has also been answered in a bang.
“There were 11 critical events, none of them in the vaccine group – 11 in the placebo group, and that settles the question of whether it prevents severe disease, which it definitely does.”
‘The data speaks for itself’
This comes after a similarly impressive result from US pharmaceutical company Pfizer and its German partner BioNTech last week, which reported a 90% efficacy of the vaccine.
Asked whether it was too early to determine whether mRNA technology had now been proven, Fauci – usually known for his cautious remarks – said the jury was definitely there.
“I think when you have two vaccines like this, they have proven to be over 90% effective, I think the messenger RNA is here, it has proven itself, and it doesn’t need to prove anything anymore.
“The data speaks for itself; it’s not me, that’s not my opinion – look at the data,”
Conventional virus vaccines use actual viruses that must be grown in chicken eggs or embryonic cell strains and then diluted, so as not to harm people – a process that could take several months.
In contrast, Covid-19 mRNA vaccines provide the genetic information needed to create a protein on the surface of the virus – called a spike protein – directly to cells in the human body, which then implant it.
This prepares the immune system to produce antibodies to the actual virus and has the main advantage of shortening the vaccine development time to weeks, once scientists have the genetic sequence for the protein they want to create.
While Moderna has caught the spotlight, Fauci has been keen to highlight the work of NIAID, who said he was responsible for developing a precise method for directing the spiky protein molecule so that it produces the strongest immune response.
But there are still some unanswered questions, including how long immunity lasts.
Fauci said he was “sure” that this would harden to some extent, as immune system cells called “memory B cells” were still ready to generate new antibodies to the virus.
But for how long it was unclear. He said, “We don’t know if it will take a year, two years, three years, or five years, and we don’t know.”
Looking ahead, Fauci said he is concerned about anti-vaccine sentiment in the United States, the country hardest hit by the pandemic.
“You have to overcome this and convince people to vaccinate, because a vaccine that has a high degree of effectiveness is useless if no one is vaccinated.”