Herd of cattle (IMAGE) University of Cambridge Caption The new study found that vaccination not only reduces the severity of TB in infected cattle, but reduces its spread in dairy herds by almost 90%. Credit Jacqueline Garget Usage Restrictions With credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.