Vaccine effects on COVID-19 infection with bivalent boosting by age group

Area of Science:

• Epidemiology
• Immunology
• Public Health

Background:

• The emergence of new SARS-CoV-2 variants necessitates ongoing evaluation of vaccine effectiveness.
• Bivalent COVID-19 vaccines were developed to target Omicron subvariants, but their impact on infection prevention requires detailed analysis.
• Understanding vaccine effectiveness across different age demographics is crucial for public health policy.

Purpose of the Study:

• To assess the time-series vaccine effectiveness against COVID-19 infection with and without a bivalent booster dose.
• To analyze vaccine effectiveness across six distinct age groups: 18-29, 30-49, 50-64, 65-79, 80+, and all ages.
• To determine if bivalent boosters provide additional protection against COVID-19 infection compared to non-bivalent vaccination.

Main Methods:

• Utilized Centers for Disease Control and Prevention (CDC) COVID-19 data.
• Analyzed rates of COVID-19 cases and deaths based on updated (bivalent) booster status.
• Employed time-series analysis to evaluate vaccine effectiveness over time.

Main Results:

• No significant difference in COVID-19 infection prevention was observed between vaccines with or without a bivalent booster dose across all analyzed age groups (18-29, 30-49, 50-64, 65-79, 80+, all ages).
• Vaccination demonstrated effectiveness in preventing COVID-19 infection for the 65-79 and 80+ age groups.
• Vaccine effectiveness against COVID-19 infection was not confirmed in the 18-29 and 30-49 age groups.

Conclusions:

• Bivalent COVID-19 boosters do not appear to offer enhanced protection against infection compared to previous vaccine formulations across most age demographics.
• Vaccination continues to be effective in preventing COVID-19 infection, particularly for older adults (65+).
• Further research is needed to confirm the effectiveness of COVID-19 vaccines in younger adult age groups (18-49).