COVID-19: mRNA vaccines require two doses for population-scale immunity
New IGC research published in Nature Communications provides highly relevant data regarding COVID-19 immunity in hospital care workers and nursing home residents in response to the Pfizer/BioNTech vaccine.
The study shows that immune responses after a single dose of the vaccine are strikingly heterogeneous among individuals and weaker in older people. The second dose, however, normalizes the presence of IgG antibodies targeting the SARS-CoV-2 spike protein in all ages.
The findings, obtained within the scope of the INFO-VAC project coordinated by Jocelyne Demengeot and Carlos Penha-Gonçalves, indicate that two doses of mRNA vaccines are required to reach population-scale immunity and that the interval between their administration should not be extended. The study also highlights the importance of serological monitoring after vaccination, namely in elderly and immunosuppressed individuals.