The benefit of 1 shot is very high for the first 6 months, it prevents the large majority of hospitalizations and deaths, but it does not prevent transmission. The decision to have a 1 month period between doses was determined by "time to market" not the ideal dosing schedule. Had drug makers tried to optimize for the ideal dosing schedule, then we would have had 6 more months of deaths while we waited for result which was a negative outcome. Now that the drugs are on the market, and we have sufficient evidence without running an additional stage 2 and 3 trial, the FDA should change guidance to suggest 2nd dose at 6 months instead of 1 month for people who aren't at high risk.