Justice
Alastair V. Campbell in Bioethics, 2017
Vaccines contain a dead or live but weakened germ that can cause a particular disease, like tetanus or smallpox. When we are given a vaccine, our body immediately produces antibodies against the foreign body. Immunization occurs when our body has developed immunity to it, either because we have been vaccinated or because we have already contracted the disease and recovered from it. Vaccination does not guarantee immunity. Natural immunity happens only after one has recovered from the actual disease, but for most people vaccination is a very effective way of preventing them from developing the full-blown illness, and it has resulted in a dramatic reduction in infectious diseases (at least in the wealthier nations of the world). Another important outcome of widespread vaccination is that it reduces the prevalence of the disease in whole populations (producing what is called ‘herd immunity’), thus reducing the risk of anyone in that group becoming infected, even if they are not immune.
Immunization
Julius P. Kreier in Infection, Resistance, and Immunity, 2022
Any disease to which a human or other animal may develop an immunity which protects against subsequent infection is a candidate for control by vaccination. Attainment of the immune state can be by active or passive means. Active immunization is based on the premise that administration of an appropriate immunogen will stimulate the afferent arm of the immune system to provide immune effector agents (cells or molecules capable of immune attack) which will protect the recipient against disease if exposure to the virulent agent occurs. Useful vaccines will do this without themselves causing significant disease. Passive immunization involves the administration of specific neutralizing or opsonizing antibodies or other immune effector molecules to protect against known or probable exposure. (Passive immunization with cells is not currently practical because of transplantation immunity against cells derived from a donor of a different histocompatibility haplotype [see chapter 11].) For the most part, this process depends on the availability of protective antibodies which must have initially been generated by an active immune response, but recent studies have demonstrated the protective effect of passively administered recombinant cytokines.
Quality Improvement in Managed Care: Using Preventive Medicine Guidelines
A.F. Al-Assaf in Managed Care Quality, 2020
The basic strategies of preventive medicine involve the use of screening, immunization/chemoprophylaxis, and counseling or education in order to avert a primary condition or mitigate secondary consequences. Screening, as a clinical process, lends itself to use of guidelines in that the inputs often involve a special population at risk, specific timing or intervals for action, and interdependence with multiple health care workers. The disadvantages of screening include multiple forms of costs and less than perfect technology to support screening tests, i.e., less than 100% sensitivity and specificity. Counseling on preferred health and safety habits is extremely labor intensive as an intervention and evidence to support each counseling intervention is often lacking. Factors such as variation in information presentation, reception by the patient, and exact compliance all contribute to the difficulty in designing controlled trials for counseling interventions. The methods of actual counseling may take several forms including: live dialogue, printed materials, video presentations, and group discussions. Immunizations generally prevent an infection or allay the harmful consequences of an infection. Immunization strategies are easier to test compared to the other preventive services. Costs and benefits are relatively simple to measure when assessing immunizations as an intervention and the outcomes may often be determined after years rather than a life-time.
Effects of Covid-19 fear on the attitudes toward Covid-19 vaccination in reproductive women
Published in Health Care for Women International, 2022
Hamide Arslan Tarus, Rüveyda Ölmez Yalazı, Tuğba Öz, Nurdan Demirci
WHO defines immunization as the “resistance of an individual to an infectious agent with the help of the administration of a vaccine” and defines vaccines as “pharmaceutical products that enable our immune system to recognize and fight pathogens such as viruses and bacteria and protect our body against the diseases caused by them.” A safe, effective and inexpensive method of preventing life-threatening infectious diseases at all ages, vaccination’s main goal is to maintain “the overall health of individuals through the prevention of death, permanent disability, severe illness and disease.” Today vaccines are used to protect the health and general well-being of all individuals from different age groups, and the WHO reports the lives of millions of people around the world have been saved by immunization (WHO, 2020b).
Determining optimal community protection strategies for the influenza vaccine
Published in Expert Review of Vaccines, 2019
Charlotte Switzer, Lorne Babiuk, Mark Loeb
For strongly immunizing infections, herd immunity is strongly driven by the contact probabilities of an infectious case [38]. Metcalf et al. [38] stated that ‘the more inherently transmissible a pathogen, the greater the proportion of the population that must be vaccinated to drive it locally extinct’ (2015: 753). The immunization threshold required to eradicate an infection generally assumes homogenous vaccination coverage, whereas real-world circumstances often find subgroups within a population who are not vaccinated for reasons of preference or access. Immunization is effective in that it reduces the number of susceptibles and increases the proportion immune. While immunization programs may aspire to population-level coverage, targeted programs which focus on vaccinating high-risk groups with high contact probabilities may be more efficient [37]. Indirect protection of vaccination can be challenging to quantify, but sources of evidence include short-term infection surveillance following vaccination introduction, and long-term changes in pathogen incidence [38]. Longitudinal changes in epidemic cycles can also indicate herd immunity effect. Improved methods to identify and measure indirect protection will have important implications for public health policy, as a better understanding of herd immunity and its impact will be insightful for logistic design of health interventions and immunization campaigns.
Advances and challenges in recombinant Mycobacterium bovis BCG-based HIV vaccine development: lessons learned
Published in Expert Review of Vaccines, 2018
Athina Kilpeläinen, Milena Maya-Hoyos, Narcís Saubí, Carlos Y. Soto, Joan Joseph
The route of immunization also plays a role in the outcome of the immune response. A single immunization of BALB/c mice with rBCG expressing HIV-1 CRF01_AE gag was shown to be able to induce HIV-1 gag-specific CTL responses and T-cell proliferation [107], and CTL responses were increased following administration of an rVaccinia vectored boost. Particularly, the responses were enhanced when the prime was delivered subcutaneous (s.c.) as compared to intradermal (i.d.), whereas delivery of the boost by either intravenous (i.v.) or i.d. injection resulted in similar responses [108]. However, i.d. is more often used as a route of immunization than s.c. (Table 1) and has been shown to induce higher HIV-specific IFN-γproducing CD8+ T cells than the s.c. route in mice immunized with rBCG expressing HIVA [109]. This suggests that although the route of immunization plays a role, other factors such as protein expression levels as well as the dose of BCG delivered can influence the outcome of the immune response. Although most studies performed in small animal models utilize a dose of 106–108 CFU (Table 1), lower doses have also been assessed [90,110]. A BCG-pan strain expressing the HIV-1C mosaic Gag (GagM) immunogen delivered at a dose of as low as 104 CFU combined with MVA was assessed pre-clinically in a prime-boost regimen in BALB/c mice and was shown to boost responses against the mosaic HIV-derived immunogen, resulting in strong-specific cellular immune responses [110].