Herd Immunity – what is it?

vaccine side effects - Trevor Gunn

  • Herd Immunity – The theory


Vaccine promoters and conventional medics from the perspective of germ theory and their newly acquired vaccines had a basis for developing further theories of epidemiology, and duly created models that they hoped could predict the incidence and severity of disease in vaccinated and unvaccinated populations. From an orthodox perspective the ‘disease’ was now a manifest externalised entity, pathogens exist and multiply within the patient and can be passed on to other susceptible individuals thereby spreading disease from person to person.

It had been observed that if the incidence of a disease naturally falls below a certain threshold it continued to decline making subsequent epidemics less likely. Declines in incidence were thought to be as a result of the increase in natural immunity through the process of having the illness, it was therefore postulated that the illness could further decline and indeed could be completely eradicated if the percentage of those immune reached above a certain threshold. The remaining susceptible individuals would not contract the disease because there were insufficient people to transmit the disease agent to them. According to this theory, sufficient numbers of immune individuals could result in the elimination of the disease forever and this phasing out of the disease could actually occur before all people had the illness and therefore before all were immune. The immunity of the majority group, the ‘herd immunity’, would protect the others as a result of what became known as the ‘herd effect’.

 “Survival of the (disease) agent is crucial—if it cannot survive, it cannot invade and infect new hosts, and the epidemic ends.”

 Epidemic theory –‘The Encyclopaedia of public Health’

Assuming that vaccines can do the job of natural immunity, researchers in the nineteenth and twentieth century, William Farr, William Hamer, Ronald Ross, A. Hedrich, Fox, and others, superimposed mathematical formulae onto vaccine uptake figures to estimate what percentage of vaccine coverage in a given population would be necessary to create sufficient ‘herd immunity’ and thereby eliminate a disease, consequently protecting those not immune by this ‘herd effect’.

  • Controversy

The concept is however controversial even within vaccine proponents of the scientific community, and yet many vaccine supporters speak of the ‘herd effect’ as though it was an absolute fact.

 “Several authors have written of data on measles which “challenge” the principle of herd immunity and others cite widely divergent estimates (from 70 to 95 percent) of the magnitude of the herd immunity threshold required for measles eradication. Still other authors have commented on the failure or “absence” of herd immunity against rubella and diphtheria. Authorities continue to argue over the extent to which different types of polio vaccine can, let alone do, induce herd immunity.”

Paul E.M. Fine Epidemiologic Reviews 1993
The Johns Hopkins University, Vol. 15, No. 2

The mathematical models designed to predict the threshold of herd immunity to give a herd effect and thus eradicate an illness are however based on many oversimplifications: Firstly the numbers of susceptible individuals are taken to be everyone in the population that is either not vaccinated or not had the illness. There is the underlying assumption that if one has not been vaccinated or had not naturally contracted the illness, then you were necessarily susceptible and therefore it was a matter of time before you would contract the disease given sufficient exposure to someone with the disease.

The rate of transmission although different for different illnesses was a fixed property that did not change over time, catching an illness was no more complicated than catching a ball and you would get no better at catching it over time or no worse, the probability of catching an illness was simply a property of the amount of people around you with sufficient balls for you to be able to catch one.

In addition, some estimates assumed that people intermingled completely randomly and that illness was not influenced by age, sex, socio-economic group, or season. Other models do make allowances for these factors but were modelled on closed systems with nobody coming into or out of the community, dying or being born. However when models started to approximate to real life scenarios things became rather more complicated.

More fundamentally the models do not take into account other known factors of disease:

  • Clearly not everyone is susceptible to contracting a particular disease and may never be susceptible for the duration of their entire life; they will be neither vaccinated nor will they have contracted the illness naturally. For example, most people are exposed to, and naturally harbour, meningococcal bacteria and because a vaccine has only recently been introduced, most people alive today have never been vaccinated, yet most will never contract meningococcal meningitis, plainly we are not all susceptible. Therefore there is no uniformity of susceptibility as assumed by these models, the vast majority of people are not susceptible to these illnesses and only a fraction of a percentage are, and they are susceptible for very specific reasons.
  • The mathematical models suggest a requirement to revaccinate populations because of the increase in numbers of susceptible individuals that are newly born, however these are the only sub-group of people classified as ‘newly susceptible’, omitting the complication of travellers in and out of communities. But additionally it implies that susceptibility to a disease cannot be newly acquired for other reasons. For example individuals may become more susceptible over time due to other illnesses, or as a result of changes in lifestyle, trauma, medication, etc., similarly individuals may become less susceptible because of other improved health factors, these changes in susceptibility are not factored in to these mathematical equations.

The basic premise of herd immunity and therefore the consequent ‘herd effect’ also relies on the following assumptions:

  • That any disease is primarily caused by only one specific microbe and that an effective vaccine against that microbe can in principle eliminate the ‘disease’. However illnesses are in fact associated with any number of possible microbes and therefore a patient’s disease is the result of the patient’s specific susceptibility:

In many instances of illnesses that are clinically indistinguishable from paralytic poliomyelitis, polioviruses are not present. We therefore have acute paralytic diseases that have been renamed according to the presence of these other viruses, e.g. coxsackie viral paralysis, and echo viral paralysis.

The Lancet, 1962:548-51

  • These mathematical models also assume that disease declines primarily as a result of immunity in the patient from either contracting the illness or being vaccinated, however vaccine promoters know that other changes in environmental conditions are also responsible for changes in incidence of disease, therefore disease can decrease for reasons other than herdimmunity and herd effect.

The cholera vaccine was one of the first vaccines acknowledged to not impact on disease rates if the conditions of sanitation and clean drinking water were not addressed, consequently the vaccine was withdrawn.

This is further demonstrated by the fact that as the disease conditions return the illnesses return, even in the vaccinated.

“… Russia made massive strides in arresting the spread of infectious diseases from 1970’s to 1990. But the health status of the Russian population declined precipitously following the collapse of the Soviet Union in late 1991 with the concomitant decline in basic living conditions. Epidemics in the early 1990s caused diphtheria to increase 54-fold and the mortality rate to increase 35-fold. Further, there has been increased incidence of numerous other diseases that were earlier under control, including cholera, typhus, typhoid, whooping cough, measles, and hepatitis.”

 ‘Health care systems in transition’ Tragakes & Lessof
The European Observatory on Health Systems & Policies 2003

Many blame the epidemics on the fall in vaccine uptake rates evident with diphtheria for example since 1993, but much of the disease cases were between 1990 and 1996 and therefore only those under two or three years old would have been affected by the low vaccine rates since 1993. Most people born before 1990 would have been vaccinated, yet as illustrated in ‘The Journal of Infectious Disease’ (01/02/00 Vol.181, B.I.Niyazmatov et al) the epidemics affected mainly older people with the 0-2 year olds accounting for only 3.3% of the 1,227 cases.

Clearly given that vaccine status was a relatively constant feature for 20 years prior to the 1990 social collapse, it was in fact the dramatic declines in standards of living that were the major impetus to the resurgence of disease despite the apparent herd immunity.

Herd effect also relies on the assumption that the development of a disease in an individual can only occur, after being infected with the disease agent from somebody that has symptoms of the actual disease, and therefore assumes that you cannot get the disease agent from asymptomatic carriers, i.e. from people with the microbes that have no symptoms of illness.

Meningococcal bacteria are carried in many of us, they are conceivably passed around from host to host but will only cause disease when a patient becomes susceptible, even from a fairly orthodox point of view, carrying microbes and having disease are two separate things.

Given that asymptomatic carriage is a reality, then the vaccine would not only have to create immunity but would have to physically eliminate the microbe from the entire person, the community and consequently from the world. However, being immune to illness does not mean the body doesn’t harbour a potential pathogen in other appropriate areas of the body, even if vaccines could create immunity, vaccines have never been shown to eliminate pathogens entirely from the body.

If the assumptions of herd immunity are correct then disease could not start in highly vaccinated populations above the herd immunity threshold.

“Many outbreaks (measles) have occurred among school-aged children in schools with vaccination levels above 98%. These outbreaks have occurred in all parts of the country.”

Centre for Disease Control
The Morbidity and Mortality Weekly Report (38:1; 11-14) 13/01/89

Some vaccines, for example the vaccine for diphtheria toxin, could in theory aid the blood immune response to the toxin from the bacteria but does not stop the bacteria proliferating on the mucus membranes or skin of the body therefore has no chance of creating a herd effect.

“…Immunization with diphtheria toxoid is protective only against the phage-mediated toxin and not against infection by the C. diphtheriae organism… Outbreaks in communities with up to 94 per cent immunization levels have been reported. Therefore, some authors have challenged whether “herd immunity” is applicable to diphtheria.”

R.T. Chen, M.D.  et al.
American Journal of Public Health, Dec 1985, Vol 75, No.12

But the main assumption underpinning herd immunity from the point of view of vaccination is of course that the vaccine affects the human body in the same way as natural immunity i.e. that it works, and that it works to a very high degree, given that many thresholds are upwards of 90%. For example assuming all the calculations and assumptions are correct to calculate this theoretical threshold, if you need a herd immunity of 90% the vaccine would have to have an efficacy of greater than 90% or the target could never be reached. A vaccine less than 90% effective could not create 90% population immunity even if you vaccinated 100% of the population. Whether the vaccine works or not is of course the whole debate and at best it has never been shown to operate in the same way as natural immunity, hence the need for repeat booster shots of vaccines as vaccinated individuals continue to succumb to the vaccinated disease, which is of course unlike natural immunity.

Therefore the idea that we need a certain percentage uptake of vaccine to create the desired threshold of ‘herd immunity’ in order to safeguard everyone, even those not vaccinated, through the ‘herd effect’ and thus eliminate the disease from the world, is a mathematical theory taken from assumptions about the natural decline in diseases that is then superimposed on vaccine theory. The mathematical equations that describe the incidence of disease in populations are very complex and are entirely different for different illnesses; they are approximate and hypothetical mathematical descriptions of the relationships between individuals and the conditions that give rise to illness, and they leave out some of the most important factors pertaining to illness in the real world.

Regarding the actual percentage vaccine uptake required in the population, and the required re-vaccination rate, to eradicate an illness, this has of course different estimates according to the different mathematical models used and also varies from illness to illness, but more significantly it has never been demonstrated in practice for any vaccinated disease.

The basic assumption that you can eliminate disease from the world, by sufficient people being immune, requires that these microbes can only exist when we have the disease and that they cannot exist if we are immune. However, it is common knowledge that individuals harbour microbes and do not have disease, therefore even if vaccines could reduce illness, they have never been shown to totally rid the body of the germ. Herd immunity and the eradication of disease, from the point of view of the vaccine induced herd effect, is a flawed hypothesis.


The only illness said to have been eradicated by vaccination is smallpox (although cases are still said to exist under a different classification) and interestingly the eradication is supposed to have occurred worldwide when in fact vaccine uptake rates were nothing like what they were supposed to be in order to achieve herd immunity.

“The disappearance of smallpox from many regions despite the continued presence of large numbers of unvaccinated susceptibles was evident from the historical record (as had been noted by Farr more than a century ago).”

Paul E.M. Fine Epidemiologic Reviews 1993
Johns Hopkins University, Vol. 15, No. 2

More importantly it was the only mass vaccinated illness before the 1900’s and the only illness to increase in death rate after the use of the vaccine, whilst all other illnesses were in decline without the use of vaccines. The symptoms of smallpox are still evident according to the World Health Organisation, only now the clinically identical illnesses are classified by different names for example ‘monkey pox’. The real biochemical proof of eradication is said to be due to the fact that the vaccine virus is not found in the natural world. Given that the vaccine viral components have been so dramatically changed over time in the ongoing production of vaccines, it is highly probable that no naturally occurring virus or similar DNA thought to be from the virus looks anything like the supposed smallpox components in the vaccine. The virus hasn’t been eradicated, it’s just that vaccine manufacturers have produced a vaccine virus that cannot be found in the natural world.

From the vaccine promoters point of reference obviously the more people vaccinated the better, however there is no verifiable percentage uptake that leads to the elimination of the disease, this is a complete mathematical hypothesis unproven with regard to any vaccine, and in any disease situation. If vaccines work, then the ‘vaccinated’ are protected, and they need not worry about those that choose to not vaccinate. The fact that vaccines cannot be given to sick people, the very people that need intervention to increase their immune function shows the potential problems with vaccines, problems that are not evident from any other natural immune enhancing intervention. Alternative and natural therapeutics, unlike vaccines, are actually designed for the sick.