Given a pathogen with moderate R0 = 2.5 that peaks seasonally in late autumn due to indoor crowding, synthesize an optimal vaccination timing strategy and target coverage to minimize peak transmission in the upcoming season (assume vaccine efficacy 85%).

• A. Conduct vaccinations exclusively during winter peak weeks and limit coverage to frontline healthcare workers because community vaccination does not influence peak timing or magnitude when R0 is moderate.
• B. Delay vaccination until peak season to ensure vaccine-induced immunity coincides with highest risk, and aim for minimal coverage because timing matters more than vaccination proportion for seasonal suppression.
• C. Begin vaccination campaigns in late summer to allow time for immune responses to develop before autumn, aim for coverage at least equal to HIT/VE where HIT = 1 - 1/R0 (HIT ≈ 60%), so target vaccination coverage ≈ 60% / 0.85 ≈ 71%, and prioritize high-contact and high-risk groups first.
• D. Avoid vaccination entirely and instead use environmental manipulation such as increasing winter humidity to exact levels that alone will reduce R0 below 1 without any need for immunization strategies.

Answer: (C)