Previous SARS-CoV-2 Infection Increases B.1.1.7 Cross-Neutralization by Vaccinated Individuals

Area of Science:

• Virology
• Immunology
• Epidemiology

Background:

• The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants necessitates evaluating immunity from infection and vaccination.
• Understanding cross-neutralization is crucial for public health strategies.

Purpose of the Study:

• To assess neutralizing activity in individuals with varying infection and vaccination histories.
• To compare immune responses against original SARS-CoV-2 and its variants (D614G, B.1.1.7).

Main Methods:

• Pseudovirus neutralization assays were employed.
• Tested serum from infected and/or vaccinated individuals.
• Evaluated neutralization against spike proteins of Wuhan-Hu-1, D614G, and B.1.1.7 variants.

Main Results:

• Natural infection parameters (timing, variant) influenced cross-neutralization.
• Unvaccinated individuals showed reduced neutralization against B.1.1.7 compared to earlier strains.
• Vaccination of previously infected individuals enhanced neutralizing responses against B.1.1.7.

Conclusions:

• Natural infection provides variant-specific cross-neutralization.
• Vaccination broadens and boosts neutralizing responses, particularly in previously infected individuals.
• Hybrid immunity (infection plus vaccination) offers robust protection against SARS-CoV-2 variants.