Wang, Z., Schmidt, F., Weisblum, Y. et al. mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants. Nature (2021). https://doi.org/10.1038/s41586-021-03324-6
Between October 2020 and January 2021, researchers studied blood samples from 20 patients who have never been diagnosed with COVID-19, and who received two doses of either the Pfizer or Moderna vaccines. They looked at plasma cells in the blood to identify coronavirus antibodies and incubated them with coronavirus spike proteins to analyze neutralizing activity, or how well the antibodies prevent virus infection. Researchers also tested the plasma against several variants of the coronavirus, which have been prevalent in the UK and South Africa.
What are the key tools used in an immune response?
- Researchers found significantly more antibodies in the blood of the vaccinated group than in that of patients who had antibodies from natural recovery.
- There was no significant difference in the neutralizing activity between those vaccinated with Moderna vaccine, and those vaccinated with Pfizer vaccines.
- Antibodies from the vaccines and antibodies from natural recovery are functionally similar, targeting the same areas of the spike protein.
- The neutralizing activity of plasma with antibodies, either through vaccines or natural recovery, varied but was slightly less effective against variants with mutations in the spike protein.
- Individual monoclonal antibodies' neutralizing activity elicited by the vaccines was reduced dramatically to the K417N, E484K, or N501Y mutant variants.
- The vaccine is still potent against all of the variants tested because combinations of these antibodies remained effective, targeting different parts of the spike protein. This suggests the importance of antibody combinations in clinical practice.
- Immune cell activity is as strong in vaccinated patients as in the natural recovered patients
- The number of memory B cells, which “remember” the virus, was initially greater in vaccinated patients three months after vaccination, and was the same as in naturally recovered patients after six months.
What does this mean?
Both the Pfizer and Moderna vaccines are safe and effective against COVID-19, even mutant strains to a lesser degree. They elicit antibodies that are functionally the same as those elicited from natural recovery, with at least a similar neutralizing activity. Vaccination can help keep you and those around you healthy, so it is important to get vaccinated as soon as you are eligible.