Opinion

The effectiveness of vaccines is complicated

Dear Dr. Roach: I was wondering if you could explain why some vaccinations seem to completely protect against a disease, while others do not. For example, smallpox was completely eradicated by vaccination, and the hepatitis B vaccine is good for life and 98% to 100% effective, according to the World Health Organization. Yet we need to have the flu vaccine each year. I understand that is partly due to different strains of flu that come through, and of course we have the coronavirus vaccine, which ... I hope you can see where this question is going. I think an understanding of the vaccines we have and how they work would be extremely beneficial to all. -- M.S.

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In supporting Ukrainians’ struggle, let’s not go crazy by canceling ?Russia’s rich culture

In 1969-70, I was a Navy disc jockey at the American Forces Vietnam Network in Saigon. Weekdays I wrote copy for radio commercials, pithy stuff warning our guys in the jungle to avoid being bitten by poisonous snakes. Army corporal Pat Sajak was our resident snake voice, who mockingly suggested on tape that soldiers should not bite snakes, either.

Read MoreIn supporting Ukrainians’ struggle, let’s not go crazy by canceling ?Russia’s rich culture