Studying the timing of breakthrough infections following COVID-19 vaccination

Updated: Feb 8

Out of the compelling information emerging day by day, there is an interesting observation that the timing between the COVID-19 vaccination and infection seems to be key in determining who experiences a breakthrough infection. The vaccination followed by a breakthrough SARS-CoV-2 infection months later offers greater protection against the Omicron variant than vaccination with infection soon after.

In a not yet peer-reviewed study, scientists from Japan collected antibodies from people who had received two doses of the Pfizer–BioNTech COVID-19 vaccine and were later infected with either the Alpha or Delta variant, testing its ability to protect cultured cells from SARS-CoV-2 infection. They demonstrated that the length of time between a person’s vaccination and the breakthrough infection was strongly correlated with how well the individual’s antibodies protected cells against infection — particularly with infection caused by Omicron.

Although this finding is generally in line with our understanding of how antibody responses mature over time, scientists think similar studies focused on vaccine boosters rather than breakthrough infections would provide concrete information.

Click here to learn more about this study.