The effectiveness of the Moderna COVID-19 vaccine remains strong, new research suggests.
The US Centers for Disease Control and Prevention (CDC) published a study that looked at the Pfizer, Moderna and Johnson & Johnson vaccines in real life and analyzed how effective they were at reducing COVID-19 hospitalizations.
Moderna came in at 93 percent effectiveness, followed by Pfizer at 88 percent and Johnson & Johnson at 71 percent.
The nationwide study involved over 3,600 adults hospitalized due to the coronavirus between March and August this year.
“Among US adults without immunocompromising conditions, vaccine effectiveness against COVID-19 hospitalization during March 11 - August 15, 2021, was higher for the Moderna vaccine (93 percent) than the Pfizer-BioNTech vaccine (88 percent) and the Janssen vaccine (71 percent),” the team wrote in the CDC’s report.
“Although these real-world data suggest some variation in levels of protection by vaccine, all FDA- approved or authorized COVID-19 vaccines provide substantial protection against COVID-19 hospitalization.”
The research team found that the biggest difference between the Pfizer and Moderna vaccines was mostly driven by a decline that started around four months after people were double-jabbed with Pfizer.
“Vaccine effectiveness for the Pfizer-BioNTech vaccine was 91 percent at 14 - 120 days after receipt of the second vaccine dose but declined significantly to 77 percent at more than 120 days,” the report read.
“Differences in vaccine effectiveness between the Moderna and Pfizer-BioNTech vaccine might be due to higher mRNA content in the Moderna vaccine, differences in timing between doses (3 weeks for Pfizer-BioNTech versus 4 weeks for Moderna), or possible differences between groups that received each vaccine that were not accounted for in the analysis,” they added.
Both vaccines use genetic material called messenger RNA to achieve immunity, but they use differing doses and slightly different formulations. The Janssen vaccine however, uses an inactivated common cold virus called adenovirus, a viral vector, to deliver immunity.
Difference between mRNA and Adenovirus-vector vaccines
Unlike other vaccines that use a weakened or inactivated germ to fight the virus, mRNA vaccines teach a body’s cells how to produce a protein, or just a piece of protein, to trigger an immune response, prompting the production of antibodies which protect us against infection if the real virus were to ever enter our bodies.
The widely accepted – and currently available - types of mRNA vaccines are the shots manufactured by Pfizer and Moderna. The advantages of both these two-dose vaccines are that they are both highly effective, non-infectious, and have no preservatives in them.
Like mRNA, Adenovirus-vector vaccines also use a specific genetic code from the “spike antigen” to protect the body against COVID-19, but it is deployed differently. Instead, the Adenovirus system uses a harmless virus as a vehicle to carry the spike into the body and create an immune response.
One of the drawbacks of this vaccine type, from a manufacturer’s perspective, is that it would require live adenovirus to be grown in large quantities in the lab first.
“A single dose of the Janssen viral vector vaccine had comparatively lower anti-SARS-CoV-2 antibody response and vaccine effectiveness against COVID-19 hospitalizations,” according to the team.
“These real-world data suggest that the two-dose Moderna and Pfizer-BioNTech mRNA vaccine regimens provide more protection than the one-dose Janssen viral vector vaccine regimen. Although the Janssen vaccine had lower observed vaccine effectiveness, one dose of Janssen vaccine still reduced risk for COVID-19-associated hospitalization by 71 percent.”