The effectiveness of the monovalent mRNA vaccine BNT162b2 and the mucosal, replication-competent but totally attenuated viral vaccine sCPD9-ΔFCS in stopping the spread of SARS-CoV-2 variants has been thoroughly compared by a research team at Freie Universität Berlin.
The research paper, titled “An Intranasal Live-Attenuated SARS-CoV-2 Vaccine Limits Virus Transmission,” was released in the journal Nature Communications. The study tackles a significant issue with existing vaccination programs, which is the restricted capacity of vaccines delivered intramuscularly to elicit strong mucosal immune responses in the upper respiratory tract, which is the main location of infection and virus shedding.
The researchers examined the effectiveness of a monovalent mRNA vaccine and the live attenuated vaccine (LAV) sCPD9-ΔFCS in stopping the spread of two SARS-CoV-2 variants in Syrian hamsters: the omicron BA.5 and the ancestral B.1. They looked into how well the vaccinations worked in two distinct situations.
The first scenario involved exposing vaccinated Syrian hamsters to infected antagonists in order to assess the protective effects of the two vaccinations. In this case, the mRNA vaccination provided no discernible protection against infection, whereas the LAV vaccine totally prevented infection.
In the second scenario, researchers looked into how the challenge virus spread from vaccinated to sick hamsters to gullible acquaintances. In this case, the LAV vaccination prevented or significantly suppressed transmission, whereas the mRNA vaccine had no effect. These findings unequivocally demonstrated that, in both cases, the LAV sCPD9-ΔFCS far outperformed the mRNA vaccination in terms of stopping the spread of the virus.
“Our results provide compelling evidence for the benefits of locally administered live attenuated vaccines over intramuscularly administered mRNA vaccines,” said Dr. Jakob Trimpert, a virologist from Freie Universität Berlin and one of the study’s lead authors. This is a major step forward in strengthening our defenses against infection and the spread of viruses, especially in light of the emergence of SARS-CoV-2 subtypes.”
