HomeHealthFour Covid vaccines create long lasting T cells against SARS-CoV-2

Four Covid vaccines create long lasting T cells against SARS-CoV-2

The cells produced by Pfizer-BioNTech, Moderna, J&J/Janssen, and Novavax vaccines can also recognise Delta and Omicron

Four Covid vaccines prompt the body to make effective, long-lasting T cells against SARS-CoV-2. These T cells can recognize SARS-CoV-2 Variants of Concern, including Delta and Omicron, new data from the La Jolla Institute for Immunology has shown.

“The vast majority of T cell responses are still effective against Omicron,” said Professor Alessandro Sette the study co-leader.

“The cells produced by the Pfizer-BioNTech, Moderna, J&J/Janssen, and Novavax vaccines won’t stop people from getting infected, but in many cases, they are likely to keep them getting very ill.”

“And this is true in all the type of vaccines we studied — and up to six months after vaccination,” added Grifoni, who also worked on the research.

These data come from adults who were fully vaccinated, but not yet boosted. The researchers are now investigating T cell responses in boosted individuals and people who have experienced ‘breakthrough’ COVID-19 cases.

The new study, published in Cell, also shows that fully vaccinated people have fewer memory B cells and neutralizing antibodies against the Omicron variant. This finding is in line with initial reports of waning immunity from laboratories around the world.

Without enough neutralizing antibodies, Omicron is more likely to cause a breakthrough infection. Fewer memory B cells means the body will then be slower to churn out additional neutralizing antibodies to fight the virus.

“Most of the neutralizing antibodies, i.e., the antibodies that work well against SARS-CoV-2, bind to a region called the receptor binding domain, or RBD,” says LJI Instructor Camila Coelho, Ph.D., who served as co-first author of the study.

“Our study revealed that the 15 mutations present in Omicron RBD can considerably reduce the binding capacity of memory B cells, compared to other SARS-CoV-2 variants such as Alpha, Beta and Delta.”

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