John Lush, London Delays too risky We all have in interest in seeing that as many as possible get first vaccine shots as quickly as possible. Yet the announced gap of more than 12 weeks for second shots puts the most vulnerable — the 80 and older crowd with chronic illness and our health-care workers — in needless jeopardy. With two new vaccines coming on stream is large supplies, is there not the possibility of reserving and directing does of the Pfizer vaccine to those awaiting their second shot? This would serve the needs of the most vulnerable without impeding swift first vaccinations. A clearly articulated, flexible policy aimed at both goals is in order.