From an evolutionary perspective in which different human populations are subtly adapted to their environment, the fact that you need vaccines makes perfect sense. You and your ancestors are not adapted to the pathogens of Haiti. You could be enjoying food with people native to the region and you could get sick, but they won't. It's a common story.

And as far as safety concerns for vaccines, they pale in comparison to the side-effects of some of the medications used to treat the diseases if you are unfortunate enough to contract them.

Vaccinate! Best bit of preventative medicine that "western" medicine has ever come up with. It's just a way to show your immune system how to prepare anti-bodies, so that if you do come in contact with the disease you can launch an immune response in a much shorter time frame then if your body had to identify viral components and manufacture antibodies from scratch. Get all your shots if you want your immune system primed for the possibility of many different diseases you haven't come in contact with before. At the very least, if you only get the flu shot you decrease the chances of viral mutations in the population as a whole (as viruses can only mutate via replication inside cells, and with the flue shot you decrease the chances of a virus getting into your cells). I could not be more pro-vax after studying microbiolgy and immunology.

If you want to increase the efficacy of any vaccine, just make sure you have a strong immune system while you are over in Haiti. Get plenty of rest for any jet-lag, drink lots of fluids, try and eat something close to your regular diet.

Okay, I see by your response that you are an anti-vaxer, so this probably isn't going to get through. But here's to trying, right? First of all, a little break down of the ingredients that you said you don't want in your body:

Mercury: It is a large misconception that vaccines contain elemental mercury. They in fact contain thimericol, which is ethyl mercury. This has a much lower toxicity than the mercury that we all consume with gusto, which is methyl mercury found at (mostly) low levels in fish and shellfish species. So, stating thimericol causes mercury poisoning is a little like cutting salt out of your diet for reasons that many soldiers died in WW1 from chlorine gas. Sure, there is a level that can result in toxicity, but it is very difficult to reach it. By eating somewhere in the neighborhood of 1/2 a filet of your average grocery store fish, you have already blown the amount of "mercury" you'd receive in a vaccine out of the water. And thimericol is not thrown into vaccines for fun- it acts as an antiseptic as a reaction to an absolutely unfortunate incident of bacterial contamination of vaccines in the past. This actually increases the safeness of the vaccine because of less specific requirements for storage requirements. Also, thimericol is only in multi-dose vaccines.

Aluminum: If you live in the states or Canada, don't even bother researching the possible effects of small amounts of aluminum, because aluminum is not used as an adjuvant here. It is only widely used as an adjuvant in Europe still.

Gelatin: Not sure why you put this on your list, there is a reason we all make bone broth and it isn't because we have things for skeletons.

Formaldehyde: As a regular part of our metabolism, we produce up to an ounce and a half of formaldehyde per day. Sure, that is not very much, but there is also not very much formaldehyde in the vaccine either. It's not like they are throwing you in a bath of the stuff- as far as your body is concerned, this amount of formaldehyde is seen like any other by product of metabolism, and treated as such.

Animal cells: Also not sure why this is on your list, I just consumed a billion of them in my steak.

Treating everyone with vaccines, specifically flue vaccines as per your hash tag, decreases hospitalization, trips to the doctor, death, heart attacks, and antibiotic use (which makes the point that vaccines contain tiny amounts of antibiotics obsolete, because it will result in a much more significant decrease overall).

Why don't flu vaccines work as well as we'd like? First of all, they are targeted, which is a poor strategy. The elderly, sick, and immunosuppressed (pregnant, HIV/AIDS etc) are the ones who are told to get the vaccine, but they are actually the ones least likely to have a positive results. If your immune system is already impaired, you are less likely to be able to produce the proper antibodies require to fight off the disease. A much more effective way of preventing illness in these populations is to instead avoid having the virus presented to them in the first place, hence the concept of herd immunity. That is why health care workers are irresponsible if they choose not to vaccinate against the flu- they are unintentionally exposing the vulnerable to a virus that, while it may not effect them, may cause a host of problems in the vulnerable one. Think of when an elderly person breaks their hip- now, breaking a hip doesn't inherently cause death, but we do know that there is an enormous jump in deaths the year following a hip fracture. While the hip fracture didn't directly cause the death, it's the vulnerability to secondary consequences that is the big problem, and the same reason can be applied to vaccines. Flus cause about 30,000 direct/indirect deaths per year in the USA alone, an astonishing number, and one that may be helped by not targeting just the vulnerable ones. For example, populations in which children who get the conjugated pneumococcal vaccination show a decreased mortality rate in the elderly in the same population. In fact, if only 20-25% of children get vaccinated, there is an 8-18% decrease in adults over 35 years, which is an enormous impact to population that was never inoculated.

Another problem with flu vaccines is people often use the n=1 "I got the vaccine but still got the flu". The fact is, yes, you can still get the flu after vaccination! But you can also get flu-like illnesses, often attributed to the flu when it isn't the same thing at all from an immunological perspective. Flu vaccinations can attenuate flus, meaning that if you get the flu your response will be better so it will decrease in duration (which would be protecting you from those secondary problems that are the real killers) and decrease the likelihood of getting passed on (thereby contributing to letting the more vulnerable live on). While it may not help you personally in every possible way you were hoping, it is the population that is greater impacted. Think, if the flu vaccine worked for just 1% of the time, you could still decrease those annual deaths by 1,800, which is pretty admirable. But, if the whole population got vaccinated, the efficacy is about 50-80% for individuals, so imagine what a massive impact that would have on longevity and vulnerable populations.

We've already applied critical eyes to nutrition, and know that it is just as important to apply critical eyes to all areas of our lives. This is one area where it has to be said that vaccines are effective on a population level, making them absolutely worth while. In fact, to not get the vaccinations actually poses dangers to other around you, making the incentive not only "I won't get sick", but altruistic as well.

Anyways, that was my big rant, sorry if you've heard all this stuff before. I need to get back to physics now (I thought I switched my major from microbiology...).

My advice, don't go.

You should have already gotten your vaccinations dude. It takes a couple weeks for your immune system to kick in with them.

How long are you going to be there, and what kind of areas are you going to be in? Haiti's a third world country with high crime and poor sanitary and health conditions. Asides from what people have mentioned (bringing stuff home), you DON'T want to get sick there.

http://travel.state.gov/travel/cis_pa_tw/cis/cis_1134.html

For malaria, you don't want to take a malaria prophylaxis for longer than a couple months. I recommend a prescription for Malarone, you usually start it two days ahead of your trip (and then two weeks after your trip) -- it's expensive BUT doesn't have anywhere near the side effects of Doxycycline (or any of the 'quines for that matter).

For vaccinations, as everyone else mentions, GET THEM! There is no discussion there. CDC is has alerts for measles and cholera outbreaks. You're running a little close to the wire for getting your Hep jabs, oral Typhoid, and Rabies vacs (none of which are pleasant, but far better than the disease). We're now getting outbreaks of whooping cough and tuberculosis in our schools because of all the hippy parents falling for the vaccination/autism scam ...

Although there's an urban legend that if you survive cholera, a nice side effect is immunity to malaria because of how cholera damages your blood cells. But then cholera has something like a 95% fatality rate so the key word here is "survive" ... good luck ...

Sometimes shots are compulsory for travel to different countries and you may be denied entry without proof of vaccination. I don't know what Haiti requires.

At this point it is too late to prepare for malaria, so just stay away from mosquitoes.

There are preventive medicines for malaria. I would recommend considering some such. Twenty years ago I got bitten by a malarial mosquito from Mexico. Acute malaria ain't fun. Can be costly, too, in terms of hospitalization and other treatment.