Nearly 10 billion doses of COVID-19 vaccines have been administered across the globe — including 522 million in the U.S. But a new study found Pfizer and Moderna’s two-dose mRNA jabs — which have been cited as “preferred” options by the CDC — appeared to be more effective at preventing death than inactivated virus vaccines.
Chinese-developed jabs, known as Sinovac and Sinopharm, use a killed version of the germ that causes the disease, much like a typical flu shot.
But scientists in Singapore say deaths per 100,000 people immunized with Sinovac numbered 11, while those dosed with Sinopharm averaged 7.8. But deaths fell to 6.2 for those with shots from Pfizer and one fatality among those who received Moderna’s.
According to the CDC, mRNA vaccines — or Messenger RNA vaccines — do not contain any live bits of the killer virus. Instead, using a single gene they teach the body’s cells to create a harmless piece of a spike protein, mimicking that which is found on the surface of the -virus that causes COVID-19. The presence of the spike protein then triggers the body to create antibodies, sparking an immune response.
The single-dose Johnson & Johnson Janssen vaccine — which along with Moderna and Pfizer are the only three jabs approved in the U.S. by the CDC — is a vector vaccine. It uses a modified version of a disabled adenovirus to carry -genetic material to prompt spike protein development and create immunity. But in December, the CDC ruled mRNA vaccines offer greater protection and fewer risks of complications, such as blood clots, than J&J’s.
