By Kathleen Berger Executive Producer for Science & Technology
COVID-19 vaccine trials accelerated towards approval for emergency use authorization at an unprecedented speed. In November, pharmaceutical companies Moderna and Pfizer reported their mRNA vaccines are 95% effective in clinical trials. The Saint Louis University Center for Vaccine Development is participating in the phase 3 trial for Moderna’s mRNA vaccine. The center’s clinical director, Sharon Frey, MD, is principal investigator.
“That type of effectiveness we don’t see in vaccines. That’s a very high rate. However, that is based on very preliminary data and we really won’t know the true answers until later on in the study,” said Frey.
In early December, an expanded data set showed the Moderna vaccine is 94.1% effective at preventing COVID-19 and 100% effective at preventing severe cases of the disease. Dr. Frey said the trial, so far, is producing amazing results.
“People should be very excited that at least two vaccines so far, both the Pfizer and the Moderna vaccines, look like they are going to be effective and will be available for use,” said Frey.
Starting in July, Moderna gave either the vaccine or a placebo – a shot of saline that does nothing – to about 30,000 people in the U.S., including participants in the St. Louis area. The vaccine is given in two doses a few weeks apart.
Moderna’s vaccine and the Pfizer-BioNTech vaccine are the new mRNA vaccines. With this new technology, the vaccines are not made up of the actual pathogen, meaning that they don’t contain weakened, dead, or noninfectious parts of a virus. Instead, they contain genetic information about the pathogen. In recent years, mRNA vaccines have a history of strong immunity against infectious diseases in animal models.
In St. Louis, Dr. Frey said she sees evidence of the Moderna vaccine working. Efficacy and safety will continue to be studied as the trial continues over the next two years. She said possible side effects are mild to moderate lasting two to three days.
“We see injection site discomfort, just like you would with any vaccine, maybe some soreness or tenderness. We see people complain of headache, muscle ache, maybe joint aches, maybe a little bit of fever,” Frey said. “If you are having side effects to a vaccine, you are certainly reacting to it and that is a good thing in the sense that your immune system is recognizing the vaccine, which we want it to, and we want it to make a strong immune response against the vaccine.”
Also in St. Louis, Pfizer’s facility in Chesterfield is playing a key role in the development of the Pfizer-BioNTech COVID-19 vaccine candidate. It’s one of three sites in the U.S. used as initial manufacturing centers for the production of the vaccine. And it’s the primary location for the production of the vaccine’s raw material –the plasmid DNA – for the vaccine antigen.
The first vaccinations in the U.S. are administered in stages to those who need it most.
“This will take many, many months,” Frey said. “We still need to do vaccine studies to see if there are other vaccines that are going to be effective. We’d like to continue them for as long as we can – to look at safety, long term safety of products.”