The definition of effective according to Merriam-Webster’s dictionary is to produce a decided, decisive, or desired effect. (1) So what is the desired effect of vaccinations? 

First of all, the purpose of vaccinations is to introduce a disease to a person so that they can develop immunity to that disease without having to experience the actual disease. Secondly, according to the CDC, the overall desired effect of vaccinations is to eliminate disease. (2)

So how effective are vaccines at preventing diseases?  Unfortunately there is no clear cut answer to that question, because there are many more factors involved in disease other than whether a person has had a vaccine or not.

However, we can draw some insights from the scientific literature to get a better handle on vaccine effectiveness. First of all, some vaccines appear to be more effective than others at preventing disease. 

When we look at the measles for example, we can see that when the vaccine was introduced there was a definite drop in the disease rate. (3) And when MMR (Measles, Mumps, and Rubella) vaccination rates fell in Europe, there was an increased incidence of measles. (4) However, when we look at a disease such as influenza, there has been much evidence that the flu vaccine has had little effectiveness on preventing the flu. (5)

We can also draw from the literature that vaccines do not offer lifetime immunity to diseases. This is especially concerning when we are vaccinating for benign diseases of childhood that have more serious complications if contracted as an adult.

And finally, we must consider that we are asking the wrong question altogether. Even if we accepted the notion that vaccinations were effective at preventing diseases, might there be larger unforeseen implications if children are not allowed to go through certain childhood diseases? In other words, might disease actually play a role in developing the immune systems of our children?

This last subject deserves to be addressed as a topic in its own right.  For now though we will simply consider the effectiveness of vaccinations in preventing disease, and leave the larger implications for another time.

Taken directly from the product insert from Merck’s Recombivax HB (Hepatitis B vaccine) is the statement “As with other hepatitis B vaccines, the duration of the protective effect of RECOMBIVAX HB in healthy vaccinees is unknown at present, and the need for booster doses is not yet defined.”

Randall Neustaedter, OMD states in his book The Vaccine Guide: Risks and Benefits for Children and Adults that antibody levels produced by [Hepatitis B] vaccination will most likely decline to non-protective levels before children reach the age when they are sexually active or exposed to other risk factors. Studies have shown that a majority of those vaccinated maintained adequate antibody levels for only 4-5 years.

This is especially concerning as the first of three doses of Hepatitis B vaccine is given at birth.  

Now given as part of the DTaP vaccine, the vaccine for Diphtheria was introduced in the 1920s, but widespread use did not begin until 1948. Prior to this widespread use, the incidence of the diseased dropped from 150 cases / 100,000 per year in the 1920’s to 15 cases / 100,000 per year in 1945. From 1970-1979 there averaged 196 cases per year, and from 1980-1999 there averaged 3 cases per year. 

Also of note, the severity of the disease significantly lessened from 1900 to 1920 as the mortality rate dropped 50% in this time before the vaccine was even introduced.

Another factor to consider in the decline of diphtheria is the fact that Corynebacterium diphtheria (the bacteria from which the toxin is produced and involved in Diphtheria) is highly sensitive to antibiotics, which began widespread use in the 1950s.

The primary difficulty in giving credit (and hence establishing its effectiveness) to the tetanus vaccine for the decline of tetanus, is that tetanus has been practically eliminated in the U.S. due to good hygiene and proper wound cleaning.

Tetanus is caused by a microorganism (an anaerobic bacterium, colostrum tetani that exists as a spore. These spores can be found in the soil and animal feces (horses, sheep, cattle, dogs, cats, guinea pigs, chickens).

These spores can enter the body through cuts and puncture wounds. Anaerobic (lack of oxygen) conditions allow spores to germinate and produce a potent toxin called tetanospasmin. It is this toxin that can cause the condition we know as Tetanus, commonly called lockjaw.

Since we now know that it is important to clean out wounds and get them oxygenated (through application of hydrogen peroxide), it eliminates most of the wounds that could potentially cause tetanus.

Between 1990 and 2000 there were 40-50 cases of tetanus per year in the U.S. The majority of these cases were people over age 60 and intravenous drug users. (CDC, 2001)

Tetanus is now recognized as primarily a disease of older adults in the U.S. On average less than 5% of tetanus cases occur in individuals less than 20 years of age. In 1999 only two cases of tetanus occurred in children.

In regards to how effective the vaccine for pertussis is, a CDC publication in 1997 stated, “The findings of efficacy studies have not demonstrated a direct correlation between antibody response and protection against Pertussis disease.”

Sanofi Pasteur’s DAPTACEL (DTaP) product inserts acknowledges this fact stating “…a serologic correlate of protection for pertussis has not been established…”

Hence, despite widespread vaccination, pertussis still occurs with regularity as a common childhood disease.

The polio vaccine has been credited with the elimination of polio in the U.S. and has been the poster child for the vaccine campaign on the quest to eliminate disease.

There has not been a natural “wild” case of polio in the U.S. since 1979, and the only cases of polio since then were caused by the oral polio vaccine, which has now been replaced by the inactivated polio shot.

Although it would be nice and neat to give all the credit to the vaccine for the elimination of polio, in the real world there are always many more variables to consider. Not that the vaccine didn’t play a role, but it should be put in perspective.

First of all, the severity of the disease had been on the decline for several decades prior to the introduction of the polio vaccines, with the mortality rate dropping 47% and 55% in the U.S. and Great Britain from 1923 to 1953.

Prior to 1990, H. influenzae type B was the most common cause of bacterial meningitis in the U.S. in children under 5 years old. (PedvaxHIB Product Insert)

“We have great concern for the increased prevalence – relatively or absolutely – of penicillin-resistant Pneumococci (Strep) coupled with the increased relative frequency of pneumococcal diseases as a result of universal Haemophilus vaccination.”

Hib is a Gram (-) bacteria, while Pneumococci is a Gram (+) bacteria. These bacteria keep each other in balance. However, we killed off much of the Hib, thus destroying the balance and have a huge relative increase in Pneumococci, and therefore an increase in Pneumococcal disease and a need for the Pneumococcal vaccine.

Vaccines: The Risks, the Benefits, the Choices, Dr. Sherri Tenpenny, 2^nd Ed. (Video)

Streptococcus Pneumoniae (Pneumococcal) is now the most common cause of bacterial meningitis in the U.S. (Prevnar product insert)

Therefore the effectiveness of the Hib vaccine perhaps is more of a reflection of a shift in the bacteria population type involved in disease rather than an elimination of bacterial meningitis.

One thing that was accomplished however was the need for another vaccine from the use of a vaccine. (Tenpenny)

Streptococcus pneumoniae is a bacterium associated with a large percentage of ear infections, meningitis, pneumonia, and bacteremia in children, and invasive disease in elderly adults.

At least 90 serotypes of pneumococcal bacterium are known, and up to one third of all U.S. types demonstrate moderate to high-level resistance to antibiotics.

A conjugate vaccine that contains the seven serotypes responsible for 80% of invasive disease was licensed in 2000 for use in infants and children, and is now recommended for use in all infants. (CDC, 2000).

The vaccine is relatively ineffective in adults (it does not prevent pneumonia), but is effective in preventing pneumonia and other invasive disease in children.

The Vaccine Guide: Risks and Benefits for Children and Adults, Randall Neustaedter, OMD

The vaccine does not prevent ear infections (See Prevnar Product Insert).

The widespread use of vaccine may cause shifts in disease pathogens to serotypes not contained in the currently licensed vaccine, thus leaving the overall incidence of problems caused by the bacterial group relatively unchanged (See Prevnar Product Insert).

Excerpts from Prevnar – Pneumococcal 7-valent Conjugate Vaccine – Wyeth – Product Insert:

“Streptococcus pneumoniae is an important cause of acute otitis media (ear infections).” See page 2. However, “because otitis media is caused by many organisms other than serotypes of S. pneumoniae represented in the vaccine, protection against all causes of otitis media is expected to be low.” (Page 11)

Although one of the studies cited in the product insert found that Prevnar reduced the overall pneumococcal otitis ear infections, it stated “children who received Prevnar appeared to be at increased risk of otitis media due to pneumococcal serotypes not represented in the vaccine, compared to children who received the control vaccine.” (See page 6)

“The minimum serum antibody concentration necessary for protection against invasive pneumococcal disease or against pneumococcal otitis media has not been determined for any serotype.” (Bottom of page 9)

Measles has historically been a common childhood disease with rare complications. It is also known as Rubeola or 9-day measles. In healthy, well-nourished children, measles has low mortality and no complications.

Throughout the twentieth century, the severity of this disease declined prior to the measles vaccine. In 1920 – 469,924 cases of measles were reported and 7,575 patients died; a 1.6% death rate. In 1955, the measles death rate was less than 0.03 / 100,000 (less than 3 in 10,000,000). In 1963, the measles vaccination program began.

The vaccine has had an impact on the disease rate of the measles (see Measles section under Diseases). Therefore there is a concern that if parents do not continue to have their children vaccinated, that the disease will make a comeback.

And in the last decade there has in fact been an increase in cases of measles, particularly in Europe. Some have blamed falling vaccination rates due to parents concerns of the possible connection of the MMR vaccine with autism.

One point of interest with the lack of high vaccination rates in Europe is a large study that was able to compare children who were vaccinated for the measles compared to those who were not, and found that vaccinated kids were more likely to have allergies than those that were not.

In 2006 there was an outbreak of mumps in the Midwest of U.S. 

“Nearly 6,600 people became sick with the mumps, mostly in eight Midwest states, and the hardest-hit group was college students ages 18 to 24. Of those in that group who knew whether they had been vaccinated, 84 percent had had two mumps shots, according to the study by the Centers for Disease Control and Prevention and state health departments.”

In Minnesota there were 180 cases of mumps reported.

Of those cases, the breakdown of vaccination rates were as follows:

29 with history of no vaccination (2 month old, too young to be vaccinated)
16 with history of vaccination, but number of doses unknown
22 with history of one dose
87 with history of two doses
4 with history of three doses

Although there have been several outbreaks of chicken pox in fully vaccinated populations, this disease is no longer the common childhood disease that every kid on the block gets. So has the vaccine been effective? Indeed it has. However it is because of its effectiveness that is causing serious health complications for our entire population (see Chicken Pox section under Diseases).

In regards to how long the chicken pox (varicella) vaccine remains effective, the product insert from VARIVAX (Merck) states “The duration of protection of VARIVAX is unknown; however, long-term efficacy studies have demonstrated continued protection up to 10 years after vaccination.” 

So the vaccine will only be effective through the years when a child is supposed to get the disease and acquire lifelong immunity, which is also address in the VARIVAX insert, stating, “In a highly vaccinated population, immunity for some individuals may wane due to lack of exposure to natural varicella as a result of shifting epidemiology.”

As stated at the beginning of the section I stated that studies have shown that there is little evidence the flu shot is effective at preventing the flu. Some of the reason for this is the fact that a majority of what people believe is influenza is in fact not the flu itself, but “influenza like illness.”

The CDC states: The majority of “influenza-like illnesses” (ILI) are not caused by a virus from the influenza family but by other viruses. (e.g. rhinoviruses, adenoviruses, and parainfluenza viruses or by bacteria such as mycoplasma or Streptococcus.

The vaccine does not prevent ILI caused by the other infectious agents. Therefore, “many persons vaccinated with the flu vaccine can still get the flu.” MMWR Nov. 9, 2001/50(44); 984-6

In a large review of studies on influenza, The Cochrane Review verified what the CDC knew all along. Researchers looked at 40 clinical trials with more than 70,000 participants and 8 non-randomized studies, and also used data from control groups in 274 influenza vaccine studies including more than 3 million observations.

They found the data reveal that, on average, there are seven cases or episodes of influenza-like illness (ILI) in a year among 100 people. But, only one of these is caused by influenza. The low background risk for influenza means that you would need to vaccinate 100 people to avoid one set of influenza symptoms in real world situations.

The review also did not find any evidence that vaccines prevent viral transmission or complications. The implications of this are enormous. First of all, one of the reasons for the big push in flu shots is to prevent serious complications such as death. Second, if the vaccine does not prevent viral transmission, when someone who contracts the virus, yet doesn’t succumb to the flu because of the vaccine (if it works), they could more easily pass the virus on to an infant.

And finally, although the CDC is now recommending flu shots for pregnant women, here are a couple of statements from the product inserts of two flu vaccines:

“Safety and effectiveness of Fluzone have not been established in pregnant women or nursing mothers or children <6 months of age.”

“Animal reproduction studies have not been conducted with Fluzone vaccine. It is also not known whether Fluzone vaccine can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Fluzone vaccine should be given to a pregnant woman only if clearly needed.”

“Safety and effectiveness of FluMist have not been studied in pregnant women or nursing mothers.”

It is difficult to ascertain whether the Hepatitis A vaccine is effective due to the fact that the incidence of the disease has been on the decline well be for the vaccine was introduced.

In 1970 the reported cases of hepatitis A in the US were 27.87 per 100,000 population. Since that time the incidence of hepatitis A has been declining so that in1999 the incidence rate was only 6.25 cases per 100,000 population.  

The information from the product inserts for the two Hepatitis A vaccines doesn’t help either. 

“[Hepatitis A Vaccine] may not prevent infection in individuals who do not achieve protective antibody titers (although the lowest titer needed to confer protection has not been determined).” HAVRIX – GlaxoSmithKline

“The duration of immunity following a complete schedule of immunization with HAVRIX has not been established.”

“The total duration of the protective effect of VAQTA in healthy vaccinees is unknown at present.”

Rotavirus is the most common cause of severe diarrhea in infants and children worldwide, according to the Centers for Disease Control and Prevention. Most children have at least one bout with rotavirus by age 2 or 3.

Although rotavirus infections are unpleasant, you can treat most of them at home with extra fluids to prevent dehydration. Occasionally, severe dehydration requires intravenous fluids in the hospital. Dehydration is a serious complication of rotavirus and a major cause of childhood deaths in developing countries.

No safety or efficacy data are available for the administration of RotaTeq to infants who are immunocompromised or who have a history of gastrointestinal disorders. (See RotaTeq Product Insert) From a basic understanding of health, it would be this group that would be most susceptible to serious complications or death due to severe diarrhea.

Gardasil has been touted as the first anti-cancer vaccine, as the Human Papillomavirus (HPV) has been linked to cervical cancer. Since vaccines for HPV are so new, it is difficult to know just how effective they will be at actually preventing cervical cancer, especially since there is little evidence that this virus actually causes cervical cancer in the first place.

An important thing to know is just how preventable cervical cancer already is. Most cervical pre-cancers develop slowly, so nearly all cervical cancers can be prevented with regular pap smear screening and prompt treatment. Survival for women with pre-invasive cervical cancer lesions is nearly 100% with early diagnosis and appropriate treatment.

With any vaccine, it is important to weigh the risks of contracting the disease against the risks of the vaccine. In light of the serious adverse reactions already reported with Gardasil (see “Are Vaccines Safe?”) in addition to the fact that there are choices in avoiding contracting HPV through lifestyle choices and also early detection and effective treatment for cervical cancer through pap smears, it is important to take a serious look at both sides of the issue when considering this vaccine.