Why booster COVID-19 injections are so important?

According to a recent study that compares the length of immunity to SARS-CoV-2 between vaccination and spontaneous infection based on declining antibody levels, it is clear that booster vaccinations are necessary to prevent reinfections and breakthrough infections.

Understanding the longevity of immunity provided by vaccinations and spontaneous infection, the best time for boosters, and the possibility of breakthrough infections are necessary for the public health response to ongoing SARS-CoV-2 outbreaks. Jeffrey P. Townsend and colleagues used comparative evolutionary analysis in a study that was published in the “Proceedings of the National Academy of Sciences” (PNAS) on June 15 to assess the longevity of immunity and chance of breakthrough infections across time.

The authors combined long-term immunological data from endemic coronavirus infections, reinfection data from close relatives of SARS-CoV-2 that infect humans, waning antibody levels following zoonotic coronavirus infections, and immunological data after SARS-CoV-2 vaccination using the relatedness of the coronaviruses.

Trends in anti-spike protein IgG antibody levels over time after immunisation with four popular SARS-CoV-2 vaccines were taken into account in the analysis. While mRNA vaccines created by Pfizer-BioNTech and Moderna elicited antibody levels greater than natural infection, leading to a median time to breakthrough infection of 29.6 months, natural infection offered a median of 21.5 months of protection from infection.

With median periods to breakthrough infection of 22.4 months and 20.5 months, respectively, the scientists discovered that viral vector vaccines developed by Oxford-AstraZeneca and Johnson & Johnson/Janssen induced antibody levels similar to those elicited by natural infection.
The authors claim that the findings show the value of booster immunisation in preventing reinfections and breakthrough infections.
The authors combined long-term immunological data from endemic coronavirus infections, reinfection data from close relatives of SARS-CoV-2 that infect humans, waning antibody levels following zoonotic coronavirus infections, and immunological data after SARS-CoV-2 vaccination using the relatedness of the coronaviruses. Trends in anti-spike protein IgG antibody levels over time after immunisation with four popular SARS-CoV-2 vaccines were taken into account in the analysis. While mRNA vaccines created by Pfizer-BioNTech and Moderna elicited antibody levels greater than natural infection, leading to a median time to breakthrough infection of 29.6 months, natural infection offered a median of 21.5 months of protection from infection.

With median periods to breakthrough infection of 22.4 months and 20.5 months, respectively, the scientists discovered that viral vector vaccines developed by Oxford-AstraZeneca and Johnson & Johnson/Janssen induced antibody levels similar to those elicited by natural infection.

The authors claim that the findings show the value of booster immunisation in preventing reinfections and breakthrough infections.