Bourla refused to answer any questions and instead repeatedly responded with phrases such as "Thank you very much" and "Have a wonderful day". Musk also revealed that his cousin, who is young and in peak health, "had a serious case of myocarditis" and "had to go to the hospital" after the Covid vaccine jab. �� COVID-19 Vaccine Side Effects: Felt Like I Was Dying for Several Days, Says Twitter CEO Elon Musk on Coronavirus Booster Shot.