Ultimately, the case for vaccination is that it saves lives. It has changed the face of medicine over the last few decades in this country. There are risks to vaccines, as there are risks to all medical treatments and, for that matter, everything in life, but the risks of the vaccine are very very small and are less than the risk of the vaccine preventable disease.

Are Vaccines are effective?


Death from chicken pox dractically reduced since vaccine has gained widespread use

"During the 12 years of the mostly 1-dose US varicella vaccination program, the annual average mortality rate for varicella listed as the underlying cause declined 88%, from 0.41 per million population in 1990-1994 to 0.05 per million population in 2005-2007. The decline occurred in all age groups, and there was an extremely high reduction among children and adolescents younger than 20 years (97%) and among subjects younger than 50 years overall (96%). In the last 6 years analyzed (2002-2007), a total of 3 deaths per age range were reported among children aged 1 to 4 and 5 to 9 years, compared with an annual average of 13 and 16 deaths, respectively, during the prevaccine years."


Hospitalizations due to chicken pox have also drastically dropped, as well as incidences of chicken pox in general

"A single dose of varicella vaccine was 80% to 85% effective in preventing disease of any severity and >95% effective in preventing severe varicella and had an excellent safety profile. The vaccination program reduced disease incidence by 57% to 90%, hospitalizations by 75% to 88%, deaths by >74%, and direct inpatient and outpatient medical expenditures by 74%. "


However it is unclear what the effect of reduced numbers of cases of childhood chicken pox are having on shingles in adults.


Measles cases were drastically reduced after the introduction of the vaccine


Cases of HIB have plummeted since the vaccine was introduced

"Hib vaccine is another good example, because Hib disease was prevalent until just a few years ago, when conjugate vaccines that can be used for infants were finally developed. (The polysaccharide vaccine previously available could not be used for infants, in whom most cases of the disease were occurring.) Since sanitation is not better now than it was in 1990, it is hard to attribute the virtual disappearance of Haemophilus influenzae disease in children in recent years (from an estimated 20,000 cases a year to 1,419 cases in 1993, and dropping) to anything other than the vaccine"


Countries that have cut back on vaccinations for Pertussis saw outbreaks and a rise in death rates from the disease

"Finally, we can look at the experiences of several developed countries after they let their immunization levels drop. Three countries - Great Britain, Sweden, and Japan - cut back the use of pertussis vaccine because of fear about the vaccine. The effect was dramatic and immediate. In Great Britain, a drop in pertussis vaccination in 1974 was followed by an epidemic of more than 100,000 cases of pertussis and 36 deaths by 1978. In Japan, around the same time, a drop in vaccination rates from 70% to 20%-40% led to a jump in pertussis from 393 cases and no deaths in 1974 to 13,000 cases and 41 deaths in 1979. In Sweden, the annual incidence rate of pertussis per 100,000 children 0-6 years of age increased from 700 cases in 1981 to 3,200 in 1985. It seems clear from these experiences that not only would diseases not be disappearing without vaccines, but if we were to stop vaccinating, they would come back."


Measles rates have also risen as vaccination rates for MMR have dropped, especially in the UK

"After the controversy began, the MMR vaccination compliance dropped sharply in the United Kingdom, from 92% in 1996 to 84% in 2002. In some parts of London, it was as low as 61% in 2003, far below the rate needed to avoid an epidemic of measles.[119] By 2006 coverage for MMR in the UK at 24 months was 85%, lower than the about 94% coverage for other vaccines.[14]

After vaccination rates dropped, the incidence of two of the three diseases increased greatly in the UK. In 1998 there were 56 confirmed cases of measles in the UK; in 2006 there were 449 in the first five months of the year, with the first death since 1992; cases occurred in inadequately vaccinated children.[120] Mumps cases began rising in 1999 after years of very few cases, and by 2005 the United Kingdom was in a mumps epidemic with almost 5000 notifications in the first month of 2005 alone.[121] The age group affected was too old to have received the routine MMR immunisations around the time the paper by Wakefield et al. was published, and too young to have contracted natural mumps as a child, and thus to achieve a herd immunity effect. With the decline in mumps that followed the introduction of the MMR vaccine, these individuals had not been exposed to the disease, but still had no immunity, either natural or vaccine induced. Therefore, as immunisation rates declined following the controversy and the disease re-emerged, they were susceptible to infection.[122][123] Measles and mumps cases continued in 2006, at incidence rates 13 and 37 times greater than respective 1998 levels.[124] Two children were severely and permanently injured by measlesencephalitis despite undergoing kidney transplantation in London.[15]"


Another link about the Measles outbreak in the UK: http://www.bbc.co.uk/news/health-13561766

More information about Measles in the US can be found here: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6020a7.htm

"The study showed that for pertussis, measles, mumps, and/or rubella, unvaccinated children had on average triple the number of infections when compared with sufficiently vaccinated children. Specifically:

  • Pertussis: Unvaccinated 15.8% - Vaccinated 2.3%
  • Measles: Unvaccinated 15% - Vaccinated 5.2%
  • Mumps: Unvaccinated 9.6% - Vaccinated 3.1%
  • Rubella: Unvaccinated 17% - Vaccinated 6.8%"

quote from: http://www.vaccinetimes.com/the-vaccinated-vs-unvaccinated-study-a-k-a-the-german-study/

Actual study: http://www.aerzteblatt.de/pdf/DI/108/7/m99.pdf

A study in Pediatrics:

"Children of parents who refuse pertussis immunizations are at high riskfor pertussis infection relative to vaccinated children. Herd immunity does not seemto completely protect unvaccinated children from pertussis.


Clinical studies also show that vaccines (in this case MMR) are effective


" Based on the available evidence, one MMR vaccine dose is at least 95% effective in preventing clinical measles and 92% effective in preventing secondary cases among household contacts.Effectiveness of at least one dose of MMR in preventing clinical mumps in children is estimated to be between 69% and 81% for the vaccine prepared with Jeryl Lynn mumps strain and between 70% and 75% for the vaccine containing the Urabe strain. Vaccination with MMR containing the Urabe strain has demonstrated to be 73% effective in preventing secondary mumps cases. Effectiveness of Jeryl Lynn containing MMR in preventing laboratory-confirmed mumps cases in children and adolescents was estimated to be between 64% to 66% for one dose and 83% to 88% for two vaccine doses. We did not identify any studies assessing the effectiveness of MMR in preventing rubella."

Adverse Events

The risk of adverse events are real and difficult to quantify. There are several methods of monitoring vaccines safety in the US. The main two are the Vaccine Adverse Event Reporting System (VAERS) and Vaccine Safety Datalink (VSD).

VAERS is a passive reporting system, anyone can go online to the VAERS website and report an adverse event. There is no screening to determine whether the even was actually caused by the vaccine. All reported cases of death and selected serious reactions are followed up by case workers from the FDA and CDC. When a large number of people report the same adverse event a focused study is done to determine if the event is actually caused by the vaccine.



VAERS is criticized both for having too many reports (there is no screening of reports, they are all included, even ones that were not caused by the vaccine or are made up) and not enough reports (many people say a significant number of reports go unreported).

VSD is an active reporting system. It uses a network of HMO's and monitors medical records. It looks for "signals," things like an increased number of primary care or urgent care visits after a vaccine, and then investigates those signals. Because reporting to VSD is automatic it does not suffer from the reporting biases that VAERS does.



Data from these sources and others is used to monitor vaccine safety. It's far from perfect, but we can use it to get some estimates of how common vaccine reactions are.

A review by the Institute of Medicine (IOM) found that serious adverse events were rare and usually reversible.



"During 1991-2001, VAERS received 128,717 reports, whereas >1.9 billion net doses of human vaccines were distributed. The overall dose-based reporting rate for the 27 frequently reported vaccine types was 11.4 reports per 100,000 net doses distributed. The proportions of reports in the age groups <1 year, 1-6 years, 7-17 years, 18-64 years, and >/= years were 18.1%, 26.7%, 8.0%, 32.6%, and 4.9%, respectively. In all of the adult age groups, a predominance among the number of women reporting was observed, but the difference in sex was minimal among children. Overall, the most commonly reported adverse event was fever, which appeared in 25.8% of all reports, followed by injection-site hypersensitivity (15.8%), rash (unspecified) (11.0%), injection-site edema (10.8%), and vasodilatation (10.8%). A total of 14.2% of all reports described serious adverse events, which by regulatory definition include death, life-threatening illness, hospitalization or prolongation of hospitalization, or permanent disability. Examples of the uses of VAERS data for vaccine safety surveillance are included in this report."

Or in other words, 11.4/100,000 vaccine doses resulted in a report to VAERS. Of those 14.2% were serious, so 1.6/100,000 doses of vaccine resulted in a serious report. Keep in mind that a report does not necessarily mean the event was caused by the vaccine.

A PDF from Australia summarizing the risk of various adverse events from vaccines


On-time vaccine receipt in the first year does not adversely affect neuropsychological outcomes

There are many studies for individual vaccines studying the rate and severity of adverse events, as well.

Concerns about additives


Thimerosal is not linked to autism. The kind of mercury in vaccines (ethyl mercury) is not the same kind of mercury that causes mercury toxicity (methyl mercury) and it behaves very differently in the body. Rather than accumulating it has a very short half life and is eliminated from the body in a matter of days.



After initially finding insufficient evidence to reject or accept a thimerosal/autism connection in 2001, in 2004 the Institute of medicine issued a report rejecting any connection between the two. For the IOM to actually reject a connection requires a very significant amount of evidence of multiple kinds; experimental, biological, and epidemiological; and multiple studies across several years. It is a resounding statement against the connection between thimerosal and autism (and other neurological disorders)


More information in the autism section.


Aluminum is present in some vaccines, as well as lots of other sources. The amount of aluminum in vaccines is very low and far less than children are exposed to from environmental sources in the first year of life. Not all vaccines have aluminum.

"During the first 6 months of life, infants could receive about 4 milligrams of aluminum from vaccines. That's not very much: a milligram is one-thousandth of a gram and a gram is the weight of one-fifth of a teaspoon of water. During the same period, babies will also receive about 10 milligrams of aluminum in breast milk, about 40 milligrams in infant formula, or about 120 milligrams in soy-based formula."



Human DNA/fetal cells were used in the development of the original virus strains. DNA is mostly destroyed in the process of making the vaccine. What isn't destroyed (trillionths of a gram, a very very small amount) is fragmented. It cannot recombine with or insert itself into the DNA of the vaccine recipient. It's not true that foreign DNA creates a crisis for the body. Your body is exposed to foreign DNA all the time, like when you get a cut or skin your knee.



Used as part of the manufacturing process, NOT an ingredient in the vaccine, only present in trace amounts. You are exposed to more formaldehyde from things like plastics or floor varnishes than you are in vaccines.


The amount of formaldehyde is less than your body naturally produces in a day. The amount in a vaccine is lower than what is naturally present in an infants body, already.


Formaldehyde is something that is produced naturally by the body!!


23 studies have found no link between autism and vaccines. This is perhaps the best researched and most debunked aspect of vaccine safety. The only study that did find a link, done by Andrew Wakefield and published in a British medical journal, has been completely discredited. Wakefield falsified data because he was working for a defense attorney who was invested in a particular outcome. Theoretical science doesn't support a link between autism and vaccines, either, although that's imperfect because we don't really understand completely what causes autism. The group "Autism Speaks" supports infant vaccination, autism rates in vaccinated and unvaccinated children are the same, and recent research shows changes in the brain due to autism occur as early as six months of age and there may be a genetic component.

Because Autism usually has it's onset at the same time as childhood vaccines are being given, the onset is often timed in conjunction with a vaccine. Children are getting vaccines every few months during their first years of life, so it's almost inevitable that the onset of something like autism would be timed coincidentally with vaccines. However, correlation does not mean causation and there is simply no research that supports a link.

There are also several studies that point to the possibility that there hasn't really been a drastic increase in the real rate of autism, but just (or primarily) an increase in detection and diagnosis.

(need links)

There is no link between autism and thimerosol. (thimerosol has since been removed from most childhood vaccines and you can do all vaccines on the schedule without any thimerosol at all by requesting certain brands).


"At this point, after ten years of research and dozens of large scale studies in multiple countries, the medical/scientific community (that is, the medical/scientific community that embraces the scientific method, with its emphasis on peer review, objective measurement, and testing of all hypotheses) is unanimous in its finding that no credible evidence exists that would support a connection between vaccinations and autism.1"


"Vaccination does not appear to cause autism or other health problems in children with inborn errors of metabolism, a researcher said here"


"A community-based case-control study found no relationship between the measles-mumps-rubella (MMR) vaccine and autism spectrum disorders, researchers reported here."


The organization Autism Speaks supports vaccination.

"Many studies have been conducted to determine if a link exists between vaccination and increased prevalence of autism, with particular attention to the measles-mumps-rubella (MMR) vaccine and those containing thimerosal. These studies have not found a link between vaccines and autism. We strongly encourage parents to have their children vaccinated, because this will protect them against serious diseases."


"The MMR vaccine is not associated with autism, researchers here said.

"We are persuaded that there is no link," according to Ian Lipkin, M.D., of the Mailman School of Public Health of Columbia University. "


Vaccines do not overwhelm the immune system

"Furthermore, no differences were found in rates of other infectious diseases whose burden was similar on each group, thus providing contradictory evidence to the claim that vaccines "overload" the immune system and make vaccinated children more vulnerable to other diseases. The same held true for medically diagnosed atopic disorders."


"The notion that children might be receiving too many vaccines too soon and that these vaccines either overwhelm an immature immune system or generate a pathologic, autism-inducing autoimmune response is flawed for several reasons:

  1. Vaccines do not overwhelm the immune system. Although the infant immune system is relatively naive, it is immediately capable of generating a vast array of protective responses; even conservative estimates predict the capacity to respond to thousands of vaccines simultaneously [30]. Consistent with this theoretical exercise, combinations of vaccines induce immune responses comparable to those given individually [31]. Also, although the number of recommended childhood vaccines has increased during the past 30 years, with advances in protein chemistry and recombinant DNA technology, the immunologic load has actually decreased. The 14 vaccines given today contain <200 bacterial and viral proteins or polysaccharides, compared with >3000 of these immunological components in the 7 vaccines administered in 1980 [30]. Further, vaccines represent a minute fraction of what a child's immune system routinely navigates; the average child is infected with 4-6 viruses per year [32]. The immune response elicited from the vast antigen exposure of unattenuated viral replication supersedes that of even multiple, simultaneous vaccines.

  2. multiple vaccinations do not weaken the immune system. Vaccinated and unvaccinated children do not differ in their susceptibility to infections not prevented by vaccines [33,-,35]. In other words, vaccination does not suppress the immune system in a clinically relevant manner. However, infections with some vaccine-preventable diseases predispose children to severe, invasive infections with other pathogens [36, 37]. Therefore, the available data suggest that vaccines do not weaken the immune system"


The IOM found cause to reject a link between multiple vaccinations and increased risk of infection or Diabetes and insufficient evidence to reject or accept a link between vaccines and other allergic disease, particularly asthma.



Vaccines do not cause SIDS. In fact, in their policy statement on preventing SIDS the AAP actually acknowledges that epidemiological data indicates a lower incidence of SIDS in recently vaccinated children. This is probably due to confounding factors and not an actual protective effect of vaccines, but is certainly evidence against vaccines causing SIDS.


In 2003 the IOM found cause to reject the connection between vaccines and some forms of SIDS and insufficient evidence to accept or reject a connection between vaccines and other forms of SIDS. This is largely due to how little we know about what causes SIDS.


Herd Immunity/Herd Effect

Herd immunity is the idea that when most of a population is vaccinated it becomes difficult for diseases to get a foothold and spread, because they run into the "wall of vaccination." There was a recent example of this at the 2012 super bowl. Someone came to the super bowl with the measles and potentially exposed thousands of people. Rather than those thousands (or even hundreds) of people taking the infection back to their community and starting outbreaks, only 14 people got sick, 13 of the 14 had chosen not to be vaccinated for the measles.


Studies have detected and measured the herd effect of many vaccines. They do this by vaccinating part of a population (often children) and then measuring the decrease in the rate of disease in both the vaccinated population (this is the vaccine effect) and non vaccinated population (this is the herd effect).



General Safety Concerns

This article explains the process vaccines go through to be approved. The process takes at least three rounds of clinical trials and lasts for years. Vaccines are always tested in conjunction with the vaccines already on the schedule.


This discusses studies that have looked into (and rejected) the various vaccines cause autism theories, as well as the theory that vaccinated children are more susceptible to infection. They also found the connection between vaccines and autism to be "not biologically plausible," meaning science as we know it does not support the connection.


DTwP (the pertussis vaccine discussed in the book A Shot in the Dark has been replaced by DTaP in the US. DTwP was a whole cell vaccine (the whole virus cell was used) DTaP is a part cell vaccine. (working on a link)

The IOM continues to study the connection between vaccines and various adverse events. The only confirmed connection is between various vaccines and anaphylaxis. For the majority of adverse events they found insufficient evidence to accept or reject a connection.


Are vaccines really necessary?

Risk varies from disease to disease, but yes, children are still at risk from these diseases. Also see "are vaccines effective"


General Resources

"Why we changed our mind and started vaccinating"

A Naturally minded mama explain why they went from non-vaxxing to vaxxing.


Great list of studies investigating efficacy and side effects of vaccines.


Story from NPR on risks of vaccine refusal


Vaccine education center from Children's Hospital of Philadelphia


WHO position papers on vaccines. Information broken down by vaccine.