Homologous protein domains in SARS-CoV-2 and measles, mumps and rubella viruses: preliminary evidence that MMR vaccine might provide protection against COVID-19

Robin Franklin; Adam Young; Bjoern Neumann; Rocio Fernandez; Alexis Joannides; Amir Reyahi; Yorgo Modis

The striking feature of COVID-19 is that it has a disproportionate impact on the elderly population, yet the paediatric populations in many reports escape with mild, if any, symptoms [Ferguson et al., 2020] . This is peculiar in a viral illness, as one would assume that the collective immunity accumulated over a lifetime would arm elderly populations with better defences than their progeny. A study by the Centers for Disease Control and Prevention (CDC) found that children are most likely and people 65 and older least likely to get sick from influenza. Median incidence values (or attack rate) by age group were 9.3% for children 0-17 years, 8.8% for adults 18-64 years, and 3.9% for adults 65 years and older [Tokars et al., 2018] . A simple answer to why COVID-19 is different could be that the elderly population do not have the physiological reserve or regeneration capacity to fight such a severe burden of disease. However, more intriguingly, the vaccination history of the individual patient might contribute to the severity of the disease.