At Tuesday's Senate Health Committee hearing, Sen. Patty Murray (D-WA) asked Dr. Anthony Fauci and CDC Director Dr. Rochelle Walensky what can be done to prevent the Delta variant's spread, as well as what data is being used to chart the vaccine and immunity. Stay Connected Forbes on Facebook: http://fb.com/forbes Forbes Video on Twitter: http://www.twitter.com/forbes Forbes Video on Instagram: http://instagram.com/forbes More From Forbes: http://forbes.com