Yeah, but it does that badly, that's the problem. It has a potential NNT of 100, which is a high number for such a common disease (in the case of a NNT of 36 in a perfect case, it's not that bad though). The high NNT also means that it is less likely to achieve any kind of herd protection.
Compared to for example the measles vaccine with a NNT of ~7, a 100 seems quite high (disclosure: but this is actually a tricky comparison and may not be fair for the flu vaccine. The NNT is heavily influenced by the baseline risk of actually getting the disease. If the baseline risk is very high to get sick in the first place, which is often the case for classic childhood disease like measles or varicella, the NNT is usually much lower even with a less effective vaccine. The NNT for the HPV vaccine against cervical cancer is somewhere in the range of 5000-8000 because of the low baseline risk of getting the disease). Furthermore, even the wikipedia article (which I object somewhat to) agrees on the fact, that for at least for the elderly, it's not very effective: And citing from the Cochrane review: In the end, these results are most likely to be too optimistic, (at least) half the studies were funded by pharmaceutical companies and while I don't want to say you cannot trust them at all, you have to take them with a pinch of salt, especially in regard of how much money they make with flu-vaccination. I do not want to say: "DO NOT GET VACCINATED", especially if you are somehow immunocompromised, be it age (old or very young) or due to some underlying disease (diabetes, etc.), the benefits easily outweighs the risks.The group most vulnerable to non-pandemic flu, the elderly, is also the least to benefit from the vaccine.
which probably isn't to blame on the vaccine alone, but also on the less robust immunologic response of the elderly.In children under the age of two the data are extremely limited, but vaccination appeared to confer no measurable benefit.
Studies funded from public sources were significantly less likely to report conclusions favorable to the vaccines
Can you clarify by what you mean with regards to your quotes about children and the elderly? If vaccination does not confer benefits to children and elderly, wouldn't that imply that the herd effect from mass vaccination would in fact be good for them and those who cannot get the vaccine? Perhaps I am misunderstanding. Does the NTT being high for healthy adults (which is what the study measured) necessarily mean that there is no benefit for those who cannot get vaccinated? Your point is well taken regarding the study funding. Did you read the fantastic WaPo expose of GSK from a few months back?
Sorry, my reply lacked a little bit of structure. Yes, this is correct (but of course it also implies that we have an effective vaccine for healthy people). If the vaccine is a perfect match, than the NNT might actually suffice when there would be a high amount of vaccination (I've found a study that got a NNT of 25 to achieve a protective herd effect)...perhaps I've been a little to rash in my statement. Right now I think it's safe to say that vaccination rates are not nearly high enough to provide herd immunity, but it may perhaps be actually possible with very high rate of vaccination (I'm no epidemiologist, so don't take my word as gospel). Added-before-I-pressed-reply: I actually found a study where children around the age of 3-15 were vaccinated and there was a significant herd immunization effect. The study says that you'd need about 80% of the children (because they are the main early vectors for spreading the virus) in a society vaccinated to achieve this. --> I'm most likely wrong As for the article you've linked..I'm afraid pharmaceutical companies are a necessary evil...but sometimes it's really depressing.Does the NTT being high for healthy adults (which is what the study measured) necessarily mean that there is no benefit for those who cannot get vaccinated?
If vaccination does not confer benefits to children and elderly, wouldn't that imply that the herd effect from mass vaccination would in fact be good for them and those who cannot get the vaccine?
I saw this and thought of you:A U.S. government analysis of this season's flu vaccine suggests it was effective in only 56 percent of people who got the shot, and it largely failed to protect the elderly against an especially deadly strain circulating during flu season.