Vaccination (the act of injecting an immunobiological substance) is not the same as immunization. vaccination does not equal or necessarily lead to immunization. Immunization refers to the body's response to the vaccination, in the form of antibody formation. Further, antibody formation does not equate to protection from the disease either, and in many cases a lot of people - due to genetic and environmental factors - do not even respond to the vaccine (they do not produce antibodies, i.e. no seroconversion, or seroresponse).

Bearing this in mind, the idea that specific individuals are being "immunized" when they are vaccinated is based largely on conjecture, since there are a range of factors (genetic and environmental) that determine the level of response to vaccination - especially considering that as we have learned more and more about the bodies immune processes, we know that antibodies do not constitute or represent the entire immune response. Thus to equate protection against disease with generation of antibodies (a very old early 20th century notion) - as is done in the marketing of forced vaccination - is an error, given that we understand a little more about the immune response complexity than we did decades ago.

This paper touches upon an aspect of the issue raised above.

Anette Fischer Pedersen (a), Robert Zachariae (a) and Dana Howard Bovbjerg (b). Psychological stress and antibody response to influenza vaccination: A meta-analysis. Brain, Behavior, and Immunity. Volume 23, Issue 4, May 2009, Pages 427-433.

(a) Psychooncology Research Unit, Department of Psychology, Aarhus University and Aarhus University Hospital, Jens Chr. Skous Vej 4, 8000 Aarhus C, DK, Denmark

(b) Biobehavioral medicine Program, University of Pittsburgh cancer Institute, University of Pittsburgh, Pittsburgh, PA, USA

Vaccination is an important public health strategy for reducing the risk of influenza at the societal level. However, at the individual level, not everyone is protected by vaccination, and increases in antibody titers may fail to reach protective levels. Several recent studies suggest that psychological stress may contribute to these individual differences. Exploring this hypothesis, we conducted a meta-analysis of 13 studies examining the influence of psychological stress on antibody responses following influenza vaccination. The studies were identified through systematic searches in MEDLINE and PsychINFO and included a total of 1158 men and women. In five studies, the increased antibody levels of caregivers following vaccination were compared to those of non-caregivers. The remaining studies focused on associations between self-reported stressful life events or perceived stress and increased antibody titers following vaccination. The meta-analysis revealed a significant negative association between psychological stress and antibody responses to influenza vaccination. While effect sizes were similar across different indicators of stress, antibody responses to the A/H1N1 and B-influenza types appeared to be more sensitive to stress than the A/H3N2 type.

It was investigated whether the association between stress and antibody response differed between young and elderly, and the results revealed significant negative associations between stress and peak antibody titers in both age groups. These findings suggest the importance of additional research to explore responsible mechanisms and possible contributions of stress to the public health problem of inadequate responses to vaccination.