A Covid-19 vaccination can lead to cross-immunization that protects against seasonal coronaviruses, according to a recent study. While this effect may not completely prevent a cold, it can significantly reduce its severity. In Europe, coronaviruses such as hCoV-229E, hCoV-NL63, hCoV-HKU1, and hCoV-OC43 have been present for years, causing mild colds in humans. A British study recently showed that an infection with one of these coronaviruses can trigger cross-immunity that protects against SARS-CoV-2. This is because the spike proteins of the harmless viruses and SARS-CoV-2 are very similar, leading the immune system to produce T-cells and antibodies that attack parts of the new coronavirus.
Researchers at the University of Ulm wanted to investigate whether the reverse is also true. They examined whether a Covid-19 vaccination also protects against seasonal coronaviruses. The team led by Jan Lawrenz conducted neutralization tests on blood samples from 24 volunteers before and after they received a full vaccination with AstraZeneca or BioNTech. The researchers observed whether the blood contained antibodies that protect against cold coronaviruses by using cell cultures. The experiments showed that all volunteers had antibodies in their blood that provided partial protection against cold coronaviruses before receiving the Covid-19 vaccine. The vaccine led to significant changes in all volunteers, with the neutralization of hCoV-OC43 improving by double and hCoV-229E by four times.
The results suggest that a Covid-19 vaccination leads to cross-immunity that also protects against cold coronaviruses. “Our study shows that the Covid vaccine enhances the neutralizing activity of sera against seasonal coronaviruses,” explains Janis Müller. While this effect may not completely prevent a cold, it can significantly reduce its severity. The study provides valuable insights into the potential benefits of Covid-19 vaccinations beyond protecting against the virus itself.
