Comparison of Safety of Different Vaccine Boosters Following Two-Dose Inactivated Vaccines: A Parallel Controlled...

Area of Science:

• Immunology
• Vaccinology
• Public Health

Background:

• Booster doses are recommended for COVID-19 vaccines to maintain immunity.
• Safety data for different COVID-19 vaccine booster types are limited.
• Understanding booster safety is crucial for public health strategies.

Purpose of the Study:

• To compare the safety of different COVID-19 vaccine booster types.
• To evaluate adverse reactions following homologous and heterologous booster strategies.
• To identify factors influencing booster vaccine safety.

Main Methods:

• A prospective, controlled study involving 320 participants who received two inactivated vaccine doses.
• Participants were randomized to receive a homologous inactivated booster or heterologous boosters (different inactivated, adenovirus type-5 vectored, or protein subunit).
• Adverse reactions were monitored for 28 days post-injection.

Main Results:

• Adenovirus type-5 vectored and protein subunit boosters (Groups C and D) showed significantly higher risks of adverse reactions compared to homologous inactivated boosters (Group A).
• Group C (adenovirus type-5 vectored) had a higher likelihood of reporting multiple reactions and specific symptoms like pain, dizziness, and fatigue.
• Gender and age influenced the risk of adverse reactions.

Conclusions:

• Heterologous COVID-19 vaccine booster strategies increase the risk of adverse reactions compared to homologous boosters in individuals previously vaccinated with inactivated vaccines.
• Specific heterologous booster types, such as adenovirus type-5 vectored vaccines, are associated with a greater risk of adverse events.
• Further research into vaccine safety profiles is warranted to guide optimal COVID-19 vaccination policies.