Herd immunity

Herd immunity

Vaccination is not effective in 100% of cases: for every vaccine, a small percentage of individuals respond very little and are not adequately protected (non-responder subjects). This is not a serious problem if a very high percentage of the population is immune to the microorganism. In this case the possibility that a susceptible individual comes into contact with an infected individual is so low that the chances of infection are minimal or almost nil.

This phenomenon is known as herd immunity.

Even those who are not vaccinated effectively and those who can not be vaccinated (for example, those who have serious illnesses that lead to a reduction in the activity of the immune system or those who are doing chemotherapy), enjoy the protection provided by the group of the vaccinated population: if however, the percentage of the vaccinated population falls below a certain critical level, which in turn depends on the contagiousness of the disease, the immunity of the flock is lost. The more a disease is contagious, the higher must be the percentage of the vaccinated population in order to eliminate or at least significantly reduce the number of cases of that infectious disease.

Vaccinating is not only an act of individual protection, but it is also an act of generosity aimed at protecting the weakest who can not be vaccinated!

When do vaccines become redundant?

The answer is very simple: practically NEVER!

A disease that has been eliminated in a region due to vaccination may return causing widespread outbreaks if herd immunity is lost.

Examples are the almost 5,000 cases of measles that occurred in Italy in the first 9 months of 2017, which caused the death of 4 people.

You can stop vaccinating against an infectious disease only when the microbe that is responsible for it disappears from all over the planet, as happened for smallpox in 1980, a result very difficult to achieve.

 

Contact your doctor or the vaccination center nearest you to clarify all your doubts about vaccinations!

 

BIBLIOGRAPHY:

Richard A. Goldsby, Thomas J. Kindt, Janis Kuby, Barbara A. Osborne. KUBY IMMUNOLOGY

Franco Giovanetti Medical Director Department of Prevention ASL CN2 Alba Bra Piedmont Region “Pediatric vaccinations: difficult questions” from Epicenter – The portal of epidemiology for public health

Dr. Giovanni Ara, Dr. Franco Giovanetti VACCINATIONS: THE ANSWERS TO THE MOST FREQUENT QUESTIONS OF PARENTS

Giovanna Zanoni, Roberta Opri, Ugo Moretti, Giuseppina Napoletano, Liera Chiara, Antonio Ferro. The real risks associated with vaccinations. Ministerial site VaccinarSì.

Kathleen Stratton, Andrew Ford, Erin Rusch, and Ellen Wright Clayton, Editors; Committee to Review Adverse Effects of Vaccines; Institute of Medicine. Adverse Effects of Vaccines: Evidence and Causality. The National Academies Press

James Fernandez, MD, PhD, RJ Fasenmyer Center for Clinical Immunology. Overview of immunodeficiency diseases. Msd manual

Constitutional Court, sentence no. 107 of 26 April 2012.

Luca Benci “The confusion in the debate about vaccinations. A new obligation or a new policy? “Quotidianosanità.it, January 28, 2017