COVID-19 Vaccine Effectiveness and Digital Pandemic Surveillance in Germany (eCOV Study): Web Application-Based...

Area of Science:

• Epidemiology
• Vaccinology
• Digital Health

Background:

• The COVID-19 pandemic necessitated rapid data collection for understanding SARS-CoV-2 and evaluating vaccine effectiveness (VE) and drug safety.
• Global health systems faced significant challenges in managing the pandemic efficiently.

Purpose of the Study:

• To evaluate the real-world effectiveness of COVID-19 vaccines using a digital participatory surveillance tool.
• To assess the potential of self-reported data for monitoring key COVID-19 pandemic parameters in Germany.

Main Methods:

• Collected self-reported data via a digital web application from May 2021 to August 2022.
• Assessed VE against laboratory-confirmed SARS-CoV-2 infection, hospitalization, and across variants.
• Used logistic regression to estimate VE after primary and third-dose vaccinations, comparing unvaccinated and vaccinated individuals.

Main Results:

• Vaccine effectiveness (VE) against infection waned from 91.2% at 4 weeks to 37.2% at 48 weeks after the second BNT162b2 dose.
• A third BNT162b2 dose increased VE to 67.6% after 4 weeks.
• Self-reported data on incidence and positivity rates correlated with official surveillance data.

Conclusions:

• COVID-19 vaccinations are safe and effective, with third doses partially restoring protection.
• Digital surveillance tools are effective for monitoring VE and can accelerate public health decisions.
• Addressing biases in digital data collection is crucial for reliable public health tools.