Study reinforces idea that IMMR vaccine heps prevent severe Covid-19
It may be the Mumps virus that is key to cross protection against Covid.

https://medicalxpress.com/news/2020-11-mmr-vaccine-covid-.html

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In a new study published in mBio, an open-access journal of the American Society for Microbiology, researchers provide further proof of this by showing that mumps IgG titers, or levels of IgG antibody, are inversely correlated with severity in recovered COVID-19 patients previously vaccinated with the MMR II vaccine produced by Merck. MMR II contains the Edmonston strain of measles, the Jeryl Lynn (B-level) strain of mumps, and the Wistar RA 27/3 strain of rubella.

"We found a statistically significant inverse correlation between mumps titer levels and COVID-19 severity in people under age 42 who have had MMR II vaccinations," said lead study author Jeffrey E. Gold, president of World Organization, in Watkinsville, Georgia. "This adds to other associations demonstrating that the MMR vaccine may be protective against COVID-19. It also may explain why children have a much lower COVID-19 case rate than adults, as well as a much lower death rate. The majority of children get their first MMR vaccination around 12 to 15 months of age and a second one from 4 to 6 years of age."

In the new study, the researchers divided 80 subjects into 2 groups. The MMR II group consisted of 50 U.S. born subjects who would primarily have MMR antibodies from the MMR II vaccine. A comparison group of 30 subjects had no record of MMR II vaccinations, and would primarily have MMR antibodies from other sources, including prior measles, mumps, and/or rubella illnesses. The researchers found a significant inverse correlation (rs = -0.71, P < 0.001) between mumps titers and COVID-19 severity within the MMR II group.

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MMR vaccine costs $112 at Costco and mine was done in 15 minutes