(WPXI) – The CEO of Pfizer says a fourth dose of the company’s COVID-19 vaccine will be needed to strengthen the immune system to be able to fight off other variants of the virus that will inevitably come in the months and years ahead. “Many variants are coming, and Omicron was the first one that was able to evade — in a skillful way — the immune protection that we’re giving,” Albert Bourla told CBS’ “Face the Nation” on Sunday. “The protection we are getting from the third (dose) it is good enough — actually quite good for hospitalizations and deaths,” Bourla said. Bourla appeared on the show two days after the second anniversary of the declaration of the pandemic that has killed more than 6 million people worldwide. According to Bourla, a fourth dose is needed because protection against the disease after three doses is “not that good against infections” and “doesn’t last very long” when new variants such as omicron emerge. (Photo: AP)