Prior infection gives far more protection than vaccination, and a combination of both is as good as it gets (although the addition of vaccination to prior infec

Prior infection gives far more protection than vaccination, and a combination of both is as good as it gets (although the addition of vaccination to prior infection gives much less additional protection than prior infection alone): https://www.cdc.gov/mmwr/volumes/71/wr/mm7104e1.htm https://www.cdc.gov/mmwr/volumes/71/wr/mm7104e1.htm