A study has reportedly shown that countries administering oral polio vaccine have a lower occurrence of COVID-19 disease in comparison to those countries administering the inactivated polio vaccine.
This suggests that the oral vaccine might either be preventing SARS-CoV-2 infection or slowing down community transmission.
Current vaccines against SARS-CoV-2 have limitations in production and distribution, especially in resource-limited settings.
However, studies have found that other prevalent vaccines can also provide protection against SARS-CoV-2 up to a certain degree, especially those using a live and attenuated pathogen that stimulates the immune system and offers temporary protection against other viruses.
To check whether the same would be applicable for COVID-19, a research group, led by Dr. Robert Charles Gallo, hypothesized that countries where polio vaccine is given orally had a lower cumulative number of coronavirus cases as compared to those that only used inactivated polio vaccine.
Along with the cumulative number of coronavirus cases in each country and the type of vaccine used there, the population of each country, the median age of inhabitants, life expectancy at birth, human development index (HDI), and finally gross domestic product (GDP) per capita, were also taken into account for the study.
A stringency index, indicating how strict the lockdown measures and restrictions were in each country, was also obtained.
Overall analysis showed that for each specific country, usage of an oral vaccine for polio was an independent predictor for the low rate of reported and diagnosed cases per 100,000 population, and while it did not prove a direct link, significant effects were found.
Out of a population of 100,000, it was found that there were an average of 4970 cases in countries administering inactivated polio vaccines, while only 1580 in those administering oral polio vaccine.
The study, therefore, suggested that oral vaccine might either be preventing SARS-CoV-2 infection on an individual level or hindering its transmission and subsequent development at a community level.
This has brought forth the possibility of creating a new class of broadly specific vaccines for mitigating COVID-19 with the help of new and traditional oral polio vaccines.