While the largest biotechnology companies in the world are working on vaccines to protect against the newly emerging variants of SARS-CoV-2, existing solutions may also have the potential to flatten the COVID-19 disease curve. Researchers at Weill Cornell Medicine and the University of Oxford have conducted studies that show that even unrelated vaccines may be helpful in the fight against COVID-19. It turns out that many vaccines provide patients with cross-resistance to coronaviruses.
Cross-resistance is a phenomenon whereby prior exposure of the immune system to one pathogen, e.g. influenza virus, changes the body’s response to another (heterologous) pathogen (e.g. SARS-CoV-2 virus).
Before COVID-19-specific vaccines appeared, scientists around the world wondered if existing formulations could be helpful in protecting against SARS-CoV-2 infections. It turns out that vaccines unrelated to SARS-CoV-2 existwhich show some degree of protection.
‘We know that unrelated vaccines have a heterologous effect, and a reasonable person might say that if they used them in a pandemic, it would be beneficial,’ said Prof. Nathaniel Hupert of Weill Cornell Medicine and lead author of the new work.
However, it was not clear how much such an intervention would help, which population would be best targeted, and how much of the population would need to receive unrelated vaccines for the effect to be significant. The team of prof. Huperta decided to check it out. Scientists used an advanced computer modeling platform – COVID-19 International Modeling Consortium (CoMo) – which is used in a pandemic.
‘If you have a model that can be adapted to a specific place and time in the context of an epidemic, you can start experimenting with different conditions of population resilience and see how things could have turned out,’ said Prof. Hupert.
Scientists modeled the probable effects of interventions with vaccines unrelated to COVID-19 on US residents. Although no specific formulation names were given in the published report, researchers chose values for cross-protection consistent with the data from measles, influenza and tuberculosis research. They found that unrelated vaccines, which would only provide 5% protection against the serious form of COVID-19, significantly reduced the number of cases.
‘This modeling study demonstrates the potential power of all vaccines to keep the immune system ready and healthy. It also strengthens the need for everyone to update their vaccination history, especially during a pandemic, concluded Prof. Hupert.
The new discovery is a “double victory”. Countries that have difficulty distributing enough COVID-19 vaccines can intervene by routinely vaccinating against other pathogens. In conjunction with non-pharmacological activitiesi.e. social distancing, hand disinfection and the use of face masks, the effects can be noticeable. However, it must be remembered that this is only an additional protection – incomparably worse than a full-fledged vaccine against COVID-19.