published July 28 in the medical journal The Lancet, comes after reports of the vaccine being possibly linked to rare blood clotting — which has caused some countries to limit its use in younger people.
The two-dose vaccine has not yet been approved for use in the United States but has received authorization from more than 170 countries.The study found that rates of the rare clotting disorder, known as thrombosis with thrombocytopenia syndrome (TTS), after the first dose were about 8.1 per million vaccines.