58

In general, the benefit of flu shots is to the general population. Taking the cited value of 40%-60% from the CDC, we can say that it might be a coin toss for you personally to be protected from influenza by the shot. However, if many thousands of people take the flu shot, even if it only works on 40% of them, it helps protect the remaining population from ...


57

This has been a controversial dispute for a long time and it can involve a lot of personal opinion, but I will try to answer this as scientifically as possible. There hasn't been any viable evidence that vaccines do cause autism. Several different theories have been proposed on why vaccines could cause autism, such as the ingredient in some vaccines ...


39

Tackling your points in turn, in inverted order: flu is an irritant but nowhere near deadly You are probably confusing the flu (influenza) with the common cold, which is colloquially often called “the flu”, or gastroenteritis (colloquially called “stomach flu”). Unfortunately these are actually very different diseases. The common cold is indeed largely ...


32

If there was close contact, if the 90% rate is accurate, and if occurrence is independent in related individuals, then you would expect 0.10 * 0.10 = 1% of contacts with 2 potentially vulnerable people to result in neither person infected. 1% sounds rare, but rare events happen all the time, and 1% isn't even particularly rare. If you know 100 families, you'...


26

You have already gotten an excellent answer on the scientific evidence for the autism-vaccination link (namely, that there isn't one). I would however like to address this part of your question directly, as an academic epidemiologist: Could there be a conspiracy in the pharmaceutical industry to cover up a link? No. It is a relatively common tactic in ...


16

Influenza deaths are not specifically tracked in those over the age of 18 but they can be estimated from death certificates. CDC estimates that from 2010-2011 to 2013-2014, influenza-associated deaths in the United States ranged from a low of 12,000 (during 2011-2012) to a high of 56,000 (during 2012-2013). Death certificate data and weekly influenza ...


15

Unvaccinated members of a population contribute to the susceptibility of the rest of the population to disease, especially vulnerable people who cannot be vaccinated. This fact is true whether or not infectious individuals are asymptomatic for a long time or a short time. Many (if not most) infectious diseases are contagious before symptoms clearly manifest ...


14

There seems to be a link (as one would expect) between areas with a higher concentration of unvaccinated individuals and disease outbreaks (see this article and the source data map). The recent (2015) measles outbreaks in California are a good example: at least 70-80% of those infected were unvaccinated (including a number of newborns too young to be ...


14

To add to @BryanKrause's answer re: rare events happen all the time, the children are not out of the woods yet. The mean incubation time for a primary VZV infection (the clinical syndrome known as chicken pox) is 14 days, but often lasts up to 21 days (see Murray Medical Microbiology, Ch. 53). The father is infectious while shedding virus, usually via the ...


13

To answer this question, first it might be useful to talk about how a vaccine actually works: basically, through introducing dead or relatively harmless (attenuated) versions of a virus or bacteria (or more recently, synthetic virus-like particles meant to mimic the outside of a virus), you induce a reaction by your immune system to defend itself. As your ...


13

Influenza vaccines do not have satisfactory effective rates of preventing flu. Flu vaccination reduces the risk of flu illness by between 40% and 60% Vaccines aren't meant to stop diseases by making 100% invulnerable individuals. Of course we want the highest possible efficacy, but the primary benefit is the large impact they have on a collective level, by ...


12

Per the CDC: A: Pertussis vaccines are effective, but not perfect. They typically offer good levels of protection within the first 2 years after getting the vaccine, but then protection decreases over time. Public health experts call this ‘waning immunity.’ Similarly, natural infection may also only protect you for a few years. In general, ...


11

If you are immunized, there is of course less risk of you contracting a given disease through contagion from an of an unvaccinated carrier. However, if your child is young enough (e.g. < 6 months old as in the question here), your child is unlikely to have had the full range of recommended vaccinations yet. (The American Academy of Pediatrics has a list ...


11

Other answers have explained why being vaccinated is generally a good idea, and I fully support the ones that do. That said, the article you've linked to does indeed present some very scary points, and I fully understand why reading something like that would give you some doubts about your own safety, so I'd like to directly tackle the key point raised by it....


9

Clostridium tetani is the causative organism in tetanus. It requires an anaerobic environment to grow so is found in soil and in the gut of animals. Person to person transmission is not possible. Vaccination state is irrelevant for both parties. http://www.cdc.gov/tetanus/about/index.html


9

The human immune system Basically, the human (and that includes all ages) immune system has two parts: The innate immune system is a very old part (which doesn't mean it's bad or superfluous, on the contrary) that is responsible for a nonspecific immune response when the body encounters a pathogen. This is a very quick response and includes inflammatory ...


9

Won't this (having a flu vaccine every year) put them in an uncharted territory as far as effects on the immune systems are concerned within a couple of decades? No You are exposed to and develop a memory response to many, many more pathogens than vaccines. Your collective immune memory from natural exposure to a pathogen is much, much larger than from ...


8

There have been no additional reports in the Morbidity and Mortality Weekly Report, which was where your original article points to regarding the efficacy of the flu vaccine. However, the most recent update on influenza activity within the United States, which was about a month later than your report, does not suggest there has been any mid-season change in ...


8

I've worked on influenza in the past, and I've never heard that particular justification for missing a flu vaccine before. I confess I can't even find it when I Google for that particular belief. There are some viral diseases where it's true that prior vaccination (or natural exposure) may cause a severe overreaction of the immune system that results in ...


8

Perhaps the question should be asked, can vaccines prevent autism? One fact of note is that postnatal infections with the vaccine-targeted infectious agents, including measles, mumps, and rubella, are not known to cause autism, although autistic features have been reported in children with congenital rubella syndrome (Chess, 1971); one study reported the ...


8

The HPV vaccine is most effective when preventing you from initial infection. While common, it's possible you haven't been infected with HPV. Even if you are, there is some benefit to still being vaccinated if you're HPV positive. The reason for this is that there are a number of different types of HPV virus, and the vaccine should provide you some ...


8

The hygiene hypothesis For some reason I hold the opinion that the immune system needs to be kept busy so it wont get weak In scientific terms, this is known as the hygiene hypothesis. It was proposed in 1989 by Strachan and is about whether people who have been exposed to a lower amount of pathogens in their childhood are more likely to develop ...


8

Apart from not getting infected due to pure chance (as mentioned already) there is one highly probable explanation (explanation, not overall chance). People get, but don't show it: asymptomatic infection Asymptomatic infection is unusual, but some cases are so mild, they go unrecognised. The primary viraemic phase is followed by a secondary viraemia to ...


7

The FluMist vaccine contains (source): Each pre-filled refrigerated FluMist Quadrivalent sprayer contains a single 0.2 mL dose. Each 0.2 mL dose contains 106.5-7.5 FFU (fluorescent focus units) of live attenuated influenza virus reassortants of each of the four strains: A/Bolivia/559/2013 (H1N1) (an A/California/7/2009 (H1N1)pdm09-like virus), A/...


6

Why is the Hepatitis B vaccine split into 3, any what is the blood test for at the end? The answer to this is really no different than this same question about any other vaccine that is given in multiple doses. I'll quote some good points and sources below but understanding how vaccines work in general first, and then getting information on the others ...


6

The problem with treating "the common cold" is that it's really a large collection of similar illnesses caused by completely different strains of virus. The effects are similar, but the causes are different. Any treatment for one type would likely be ineffective against many of the others. Here are some stats from a Business Insider article: A "cold" can ...


6

Short answer, loaded with opinion: Inherent difficulties present but mainly not enough resources allocated to this problem until now. Longer version, based on other expert opinions and research results –– or really: challenges: The reasoning in the question is indeed plausible and puzzling. It should be easy, on the face of it. Only that this pathogen is ...


6

There is evidence that delaying or refusing immunization puts children at risk of disease here and here. There is also evidence that delaying or spreading out MMR or MMRV in particular puts children at greater risk of reactions (febrile seizures), rather then reducing the risk. I'm not aware of any study demonstrating the opposite.


5

Yes, you can contract it, but it is very unlikely. The chickenpox vaccine is a live (attenuated) vaccine, meaning that it was weakened. People who get chickenpox vaccines can spread the vaccine-strain varicella-zoster-virus to others. However, this happens very rarely. Source: CDC In a 10 year study of Varivax (the Merck vaccine), this happened in ...


5

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that protects red blood cell against oxidative damage. G6PD deficiency is one the most common genetic disorders. Most of the patients with G6PD deficiency remain clinically asymptomatic. However they are at increased risk of developing acute haemolytic anemia (AHA) in the presence of oxidative agents, ...


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