Consider the flu vaccine. This is one of the most widely used vaccines, and it only lasts for about a year. My understanding is it's due to the rate at which

Consider the flu vaccine. This is one of the most widely used vaccines, and it only lasts for about a year. My understanding is it's due to the rate at which the virus mutates, as you allude. Essentially the flu is different every year, and the vaccines only work against last version as more variants are created. COVID similarly mutates frequently, leading to a similar situation. In contrast, monkeypox and HPV do not mutate frequently leading to variants.