Altmann explains that one person walking down the street might have been infected with the original Covid-19 variant, then received two doses of the Pfizer vaccine… then been reinfected with the Delta strain. Meanwhile, another person may have received a different brand of vaccine, and been infected with a different variant – such as the Alpha strain first identified in Kent.

อ่านต่อเพิ่มเติม โรงเรียนบ้านนาเหนือ

สาระสำคัญ  เส้นเอ็น