If they’re positive, the company plans to apply for emergency use authorization from the US Food and Drug Administration and make the vaccine available to the public.
Two vaccines already have FDA and European authorization and three are authorized in the UK. Here’s how some of the top coronavirus vaccines and vaccine candidates work.
Pfizer and its German-based partner BioNTech use a new approach to making vaccines that uses messenger RNA or mRNA.
This design was chosen for a pandemic vaccine years ago because it’s one that lends itself to quick turnaround. All that is needed is the genetic sequence of the virus causing the pandemic. Vaccine makers don’t even need the virus itself — just the sequence.
In this case, BioNTech researchers used a little piece of genetic material coding for a piece of the spike protein — the structure that adorns the surface of the coronavirus, giving it that studded appearance.
Messenger RNA is a single strand of the genetic code that cells can “read” and use to make a protein. In the case of this vaccine, the mRNA instructs the muscle cells in the arm to make the particular piece of the virus’s spike protein. Then the immune system sees it, recognizes it as foreign and is prepared to attack when actual infection occurs.
“RNA is like snapchat messages that expire. RNA vaccines do NOT become a permanent part of your body. They are temporary messages instructing cells to make one viral protein temporarily,” Shane Crotty, a virologist at the La Jolla Institute for Immunology, said on Twitter.
“It takes 25 different coronavirus proteins to make a coronavirus, so there is no worry about the RNA making a virus.”
Clinical trials showed Pfizer’s vaccine was 95% effective in preventing symptomatic infections. Pfizer is working to show the vaccine can prevent all infections, including those that don’t cause symptoms.
MRNA is very fragile so it’s encased in lipid nanoparticles — a coating of a buttery substance that can melt at room temperature. That’s why Pfizer’s vaccine must be kept at ultracold temperatures of about minus 100 degrees F (minus 75 degrees C). That means special equipment is needed to transport and store this vaccine.
Pfizer’s vaccine won FDA EUA in December and is being delivered to millions of people in the US and UK. The US government has contracted to buy 200 million doses of Pfizer’s coronavirus vaccine.
Moderna
And like the Pfizer/BioNTech vaccine, it codes for cells to make a piece of the spike protein. That was a careful…
Read More: How Pfizer/BioNTech, Moderna, AstraZeneca and other leading coronavirus