|
| |
| | biol2080 |
 | | Unfortunately, it is often a property of the pathogen rather than the vaccine which determines the ability of the a vaccine to achieve successful herd immunity in the absence of substantially less than 100% compliance. | | | Unfortunately, except for live vaccines, which often have a portal of entry which does not require syringe and needle delivery, most vaccines must be delivered by syringe. | | | While from a public health point of view vaccines are wonderful things, in practice it is not necessarily easy to engineer effective vaccines against any given disease. |
|
http://www.mansfield.ohio-state.edu/~sabedon/biol2080.htm
(3250 words)
|
|
| |
| | Pros and Cons Of Closed Herds Concepts |
| | In essence, the closed herd concept attempts to augment stringent biosecurity by eliminating live animal inputs as opportunities for disease entry into the herd. | | | The perception that simply closing a herd will allow immunity to stabilize and eliminate most diseases may be too optimistic. | | | Historically, closed herd strategies have been applied as temporary interventions to control a particular health problem. |
|
http://nationalhogfarmer.com/mag/farming_pros_cons_closed
(2632 words)
|
|
| |
| | Specialist Advocates Careful Attention To Cattle Immuinity |
| | This may not be practical for most operations, but if BRD or its associated pathogens are a problem it may be the best approach to controlling losses, Gill says. | | | "It is difficult to make blanket statements about what a herd needs to be immunized against," Gill says. | | | Developing herd immunity is becoming more important as the incidence and spread of disease continues to increase. |
|
http://www.livestockweekly.com/papers/99/11/04/whlgill.asp
(1794 words)
|
|
| |
| | Immunity - Evolution: Library: Double Immunity |
| | Systemic immunity might be a combination of mucosal and peripheral immunity or All immunoglobulins participate in peripheral or mucosal immunity by | | | A digitized information base and broadband video channel for science, medicine and health, incorporating the AIDS and MEDICAL ARCHIVES of Meditel | | | Other researchers should contact their own libraries for access to Immunity. |
|
http://substance-abuse.allworldsites.com/q/substance-abuse-immunity.htm
(241 words)
|
|
| |
| | The animal story -- Roeder 331 (7527): 1262 -- BMJ |
| | Combined with the understanding that it was difficult to achieve | | | immunity to rinderpest, explaining how elimination of rinderpest | | | immunity conferred by vaccination because field studies and |
|
http://bmj.bmjjournals.com/cgi/content/full/331/7527/1262?ehom
(1142 words)
|
|
| |
| | herdimmune |
| | Herd immunity is an important concept in vaccination. | | | The definition of herd immunity is “the resistance of an entire group of animals to disease control by the presence, in that group, of a proportion of immune animals”. | | | Herd immunity reduces the probability of a susceptible animal meeting an infected one so that the spread of disease is slowed down or stopped altogether. |
|
http://duke.usask.ca/~misra/virology/stud2005/vaccines6/herdimmune.html
(71 words)
|
|
| |
| | Herd Immunity |
| | Concomitant to that is the powerful emotion that your unimmunised child is a threat to even the immunised children. | | | Barbara Sumner-Burstyn: Immunisation choice challenges the herd mentality | | | The battery of rigorous, long-term, double-blind, placebo-based controlled trials that are the benchmark in other medical fields are missing from the development of many modern immunisation serums. |
|
http://www.alternative-doctor.com/vaccination/herdimmunity.htm
(957 words)
|
|
| |
| | E-News: Herd Immunity and the Varicella Vaccine - Is it a good thing? |
| | Unlike recovery from the natural disease, vaccines do not give permanent immunity as has been repeatedly demonstrated with the failure of the measles and pertussis vaccines to confer permanent immunity. | | | The risk of hospitalization related to varicella infection is 5 to 10 times higher in adults than in children with the disease.4 It is therefore conceivable that the herd immunity documented by Clements et al may have a negative effect on those who have not been vaccinated. | | | The authors conclude that this decrease in varicella in the unvaccinated children is a demonstration of herd immunity and is a welcome effect of the vaccine. |
|
http://www.vaccinationnews.com/DailyNews/May2001/E-NewsChixPoxVaxImm.htm
(733 words)
|
|
| |
| | Herd immunity |
| | In intensive salmon aquaculture systems, reduced disease risks are thought to justify the observed level of side-effects following current vaccination practices. | | | Herd immunity is more effective as the percentage of people vaccinated increases. | | | I must question the theory of herd immunity. |
|
http://www.vaccinetruth.org/page_28.htm
(1036 words)
|
|
| |
| | Newhouse A1 |
| | More than 85 percent of children were vaccinated in the Michigan study, and rates were even higher in the years that Japan carried out its aggressive child vaccination program. | | | The object: to measure how well flu is controlled through "herd immunity" -- a term applied when sufficient numbers of people are immune to a virus that they provide a firebreak against its spread. | | | The tactic has shown promise in earlier studies and differs from current U.S. policy, which generally advocates vaccinations for the most vulnerable, including seniors, very young children and people with chronic illnesses. |
|
http://www.newhousenews.com/archive/seeman102604.html
(1020 words)
|
|
| |
| | DairyBiz -- Animal Health -- Maintaining Herd Immunity -- Brought to you by Pfizer |
| | Pfizer recognizes that sound biosecurity practices protect your reputation, your way of life and your herd's potential. | | | Dairy producers need to examine their management skills, health programs, and biosecurity programs with the immune system in mind. | | | f we want to protect our resident herds from profit-taking illness and disease, it is critical to appreciate and address the resistance levels of the individual animals and of the herd in general. |
|
http://www.moomilk.com/archive/a_health_38.htm
(1732 words)
|
|
| |
| | Herd immunity and the HIV epidemic. |
| | O'Connor WT; Department of Family Practice Medicine, School of Medicine,; University of California, Davis 95616. | | | Herd immunity describes the collective immunocompetence of a population and its ability to resist disease. | | | An association between these superimposed secondary infections and the human immunodeficiency virus (HIV) epidemic can be made since the HIV's imposition on individual immunity has ramifications on a population level through a decline in herd immunity. |
|
http://www.aegis.com/aidsline/1991/nov/M91B0711.html
(352 words)
|
|
| |
| | Immunisation |
| | Factors affecting herd immunity - Strength of a person's immune system | | | This animation demonstrates how herd immunity is achieved. | | | Factors affecting herd immunity - How infectious the disease is |
|
http://www.immunisation.nhs.uk/article.php?id=78
(110 words)
|
|
| |
| | Is the theory of "herd immunity" flawed? |
| | "Herd" immunity is a theory which purports to explain how an entire group can be protected from disease. | | | In fact, circulating virus is known to boost the immunity of the vaccinated (and perhaps even those naturally immune), thereby prolonging the apparent effectiveness of the vaccine (and maybe even natural immunity). | | | Another possible problem is that vaccines often do not prevent transmission, instead merely preventing full-blown cases of disease (i.e., causing mild or subclinical cases). |
|
http://www.vaccinationnews.com/Scandals/July_5_02/Scandal23.htm
(613 words)
|
|
| |
| | immunity, types of |
| | Immunity is the ability of the body to resist becoming infected upon exposure to a microorganism or parasite. | | | immunity transferred to the patient "passively,"rather than formed by the patient himself; usually in the form of antibody protein substances | | | herd immunity is the principal behind rubella immunization: if all the kids who could possibly transmit the disease to expectant mothers are immune, the expectant mothers will be protected even if their antibodies are low |
|
http://www.drhull.com/EncyMaster/I/immunity.html
(211 words)
|
|
| |
| | Vaccination |
| | Historically, for example, vaccination for respiratory disease was done at the time of weaning. | | | While immunity develops to a different degree in each animal, all animals begin life with no immunity at all. | | | Vaccination to develop immunity is carried out when it appears the disease challenge will exceed the animal’s natural immunity. |
|
http://www.news.farmca.com/marchapril2000/vaccination.html
(681 words)
|
|
| |
| | Herd immunity - Wikipedia, the free encyclopedia |
| | It is therefore the general aim of those involved in public health to establish herd immunity in the populations for which they are responsible. | | | This is herd immunity - the fact that others in the herd or population have been vaccinated provides protection to all others, whether or not vaccinated themselves. | | | However, this is not always possible, or may fail after time. |
|
http://en.wikipedia.org/wiki/Herd_immunity
(294 words)
|
|
| |
| | Steve Quayle News Alerts |
| | Today, "herd immunity" typically refers to a situation in which so much of a population is immune to a given disease that the few scattered "susceptibles" are as good as immune to it. | | | The reason is that herd immunity threshold is mathematically related to another key concept in epidemiology called the "basic reproductive number." Expressed as R 0, this is the average number of people each newly infected person will infect in a population when everyone is susceptible. | | | Intuition suggests that the more contagious a disease, the greater is the percentage of the population that must be immune to achieve herd immunity. |
|
http://www.stevequayle.com/News.alert/03_Disease/030922.measles.html
(1079 words)
|
|
| |
| | mathepi.com |
| | In effect, the herd is immune, even though there is an individual calf that's not. | | | Well, even though the herd is no longer completely susceptible, the same principle can be applied. | | | You can become immune either by having had a disease before or by receiving a vaccine. |
|
http://www.mathepi.com/maindir/herd.html
(585 words)
|
|
| |
| | Herd immunity to helminth infection and implications for parasite control |
| | We describe here a simple mathematical model for the population dynamics of helminth infections which mirrors the development of a degree of acquired immunity within populations which are genetically heterogeneous with respect to immunological responsiveness. | | | We interpret observed patterns in the age-specific intensity of infection and attempt to understand the possible effects of control measures based on chemotherapy and vaccination. | | | Despite much research on immunological responses to helminth parasites, knowledge of the dynamic interplay between levels of herd immunity in humans and the rates of exposure, establishment and mortality of parasites remains limited |
|
http://www.nature.com/doifinder/10.1038/315493a0
(452 words)
|
|
| |
| | INDUCTION OF HERD IMMUNITY AGAINST PERTUSSIS WITH A MONOCOMPONENT PERTUSSIS TOXOID VACCINE |
| | The study provides evidence that the vaccine induced herd immunity because the decrease in the pertussis incidence was higher than expected based on individual protection and vaccination rate and because the disease incidence decreased in all age groups. | | | Herd immunity against pertussis was studied in the Gצteborg area (population 778,597) of Sweden when mass vaccination with pertussis toxoid of children born during the 1990s was instituted in 1995. | | | Significant decreases in B.pertussis isolates and hospitalizations occurred in all age groups including infants and adults. |
|
http://www.kenes.com/espid2001/ESPID_Abstracts/184.htm
(239 words)
|
|
| |
| | Risk Reduction Plan Stabilizes Herd Immunity |
| | Hargis helps the farm with detailed recordkeeping and identification, with the goal of having an on-farm system that assures the staff person with the least experience can always breed the right sow with the right semen. | | | He just hopes that when it does, all the programs that have been developed are enough to keep it at bay. | | | Pro-Net is a farrow-to-wean system in which the owners receive 15- to 18-day-old pigs to grow out in their own barns. |
|
http://nationalhogfarmer.com/mag/farming_risk_reduction_plan/index.html
(1620 words)
|
|
| |
| | Liver Facts - Vaccination Tames Hepatitis A Infection |
| | All three experts pointed out that there is a natural five- to 10-year cycle of hepatitis A infections, and it's possible that some of the decline seen was simply part of the natural cycle. | | | Targeting one cohort appears then to have a population effect, called herd immunity," explained Dr. Pierre Van Damme, author of an accompanying editorial in the same issue of the journal and a professor of social medicine at the University of Antwerp, in Belgium. |
|
http://www.liverfacts.com/ms/news/526804/main.html
(839 words)
|
|
| |
| | The Politics of School Immunization HHCS - May 2005 |
| | Concerns about the new "personal/philosophical" exemptions include speculation about "herd immunity." States have always granted some exemptions from school vaccination—on medical grounds, or if parents have religious objections to vaccination--but that has generally involved a relatively small number of children in any given school or classroom. | | | On the other hand, parents can read well-documented reports of occasional ill effects such as fevers and seizures from vaccination, and they have access to widespread allegations on the Internet that vaccination may be linked to disabilities such as autism. | | | The non-immunized are in effect "free riders," relying on the efforts of more compliant peers to keep them safe. |
|
http://www.healthinschools.org/ejournal/2005/may1.htm
(1114 words)
|
|
| |
| | Imperfect vaccines and herd immunity to HIV. |
| | This paper shows how to equate different aspects of imperfection in a prophylactic vaccine in terms of impact upon levels of herd immunity, and hence upon the vaccine coverage required for eradication. | | | The paper goes on to compare predicted patterns of seroconversion that would be observed in clinical trials and in community-wide vaccination campaigns for vaccines that confer the same levels of herd immunity but are imperfect in different ways. | | | Such comparisons reveal that an otherwise perfect vaccine that gives protection which wanes with a half-life of 10 years is only as good as a vaccine that works in 30% of people giving them complete, lifelong protection. |
|
http://www.aegis.com/aidsline/1993/dec/M93C0154.html
(384 words)
|
|
| |
| | Science Museum MMR: An Injection of Sanity? Herd Immunity |
| | The vaccinated animals who are directly protected against the disease shield those who haven't had the jab - such as babies under twelve months old and some ill children - from getting measles. | | | Imagine the whole population as a herd of animals. |
|
http://www.sciencemuseum.org.uk/antenna/mmr/nakedscience/143.asp
(82 words)
|
|
| |
| | Vaccination and herd immunity to infectious diseases |
| | Mathematical models of the spread and persistence of infection provide important insights into the problem of how best to protect the community against disease. | | | An understanding of the relationship between the transmission dynamics of infectious agents and herd immunity provides a template for the design of effective control programmes based on mass immunization. |
|
http://www.nature.com/doifinder/10.1038/318323a0
(588 words)
|
|
| |
| | Synthetic Life |
| | Any threat from bioterrorism will arise only if mass vaccination stops (23) and herd immunity against poliomyelitis is lost. | | | There is no doubt that technical advances will permit the rapid synthesis of the poliovirus genome, given access to sophisticated resources. |
|
http://www.evilbible.com/Synthetic_Life.htm
(2376 words)
|
|
|
