BREATHE has contributed to a study into the effectiveness of two-doses of the Pfizer-BioNTech vaccine and how it changes over time in adolescents.
BREATHE associated project, EAVE II (Early Pandemic Evaluation and Enhanced Surveillance of COVID-19) uses patient data to track the COVID-19 pandemic and vaccine effectiveness across Scotland. Similarly, The Vigivac Project is Brazil's digital surveillance initiative that seeks to evaluate the effectiveness of vaccines against COVID-19. Through their collaboration, EAVE II and The Vivac Project were able to work on statistical analyses far more powerful than if done separately.
With cross-country comparison studies such as these, if the same or similar patterns can be observed across two different countries where circumstances are different (e.g. timing of waves of infection, timing of vaccination), we can more safely identify what is causing these patterns to form. In a similar vein, it minimises the chances of bias relating to factors such as access to health care, occurrence of symptoms, and health seeking behaviour skewing our results.
Currently, little is known about how COVID-19 vaccine effectiveness (VE) changes over time in 12–17-year-olds. This is especially the case with the Omicron variant of coronavirus (SARS-CoV-2), known as B1.1.529. To date, nobody has reported data about how well young people aged 12-17 are protected against infection and disease after two doses of a COVID-19 vaccine.
Understanding how vaccine protection wanes is important because it can help to inform future vaccine programmes for young people, and potentially prevent further illness and education disruption. In this study, analysts looked at symptomatic SARS-CoV-2 infection and severe COVID-19 in 12-17 year-old adolescents in Scotland and Brazil. They studied different time periods after receiving two doses of the Pfizer BioNTech vaccine (BNT162b2), which is the main vaccine licensed for children in this age group.
Results showed that, during the Omicron period, the protection given by the Pfizer- BioNTech vaccine against severe COVID-19 remained strong 98 days after the second dose. However, vaccine protection against symptomatic infection began to wane 27-days post-second dose.
Read the Plain English Summary on the EAVE II website
Access the paper through The Lancet Infectious Diseases