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

Patients with a high severity illness had on average increased levels of rubella IgG (161.9+147.6 IU/ml) compared to patients with a moderate severity of disease (74.5+57.7 IU/ml) (Fig. 5) . In comparison, Immunoglobulin M (IgM) levels were 0.21+0.16 IU/ml in severe disease and 0.26+0.21 IU/ml in moderate disease. Whilst we accept that it is possible that this trend could be representative of preinfection protection to rubella infection, it is not possible to determine this. In a study of 160 women of child bearing age, the IgG levels of non-infected patients measured between 24-143 IU/ml, suggesting that it is unlikely that those who developed severe symptoms of the disease had IgG levels far in excess of this prior to infection [Seker et al., 2004] . To test the specificity of this antibody response and to exclude the possibility that SARS-CoV2 infection was not driving a non-specific antibody response, we tested the six patients with the (3 from severe and 3 from moderate category) highest IgG titres and performed an ELISA against a varicella zoster virus epitope. All 6 patients returned positive samples ranging 1.86-3.46 (Ab Index) with reports in the literature of a response to a VZV vaccination being around 690 (Ab Index) [Smith-Norowitz et al., 2018] . This is consistent with the hypothesis that patients are specifically responding to SARS-CoV2 by identifying homology to rubella.