concerns of vaccines, and the prevention and treatment of vaccines

SHE 3.4 the decision to participate in immunisation programs can be influenced by the social, economic and cultural context in which it is considered

what are the issues with the use of vaccines

• allergic reaction

• isolating virus from animal tissues

• preservatives

allergic reaction

issues usually stems from medium the vaccine was cultured in.

example - influenza vaccines are often cultured in fertilised eggs

isolating virus from animal tissues

• If animals are used as a culture medium it is difficult to isolate

• Also religious concerns.

• Concerns stem from humans ingesting products from animals infected with “Mad Cow Disease” in the UK

preservatives

• chemicals used as preservatives

• Individuals are concerned that they can affect the nervous system and lead to other health issues

• examples - acetone and aluminium phosphate

what are ethical concerns with vaccines

• treatment of animals

• some require human tissue

• testing of vaccines

treatment of animals

•Viruses can only reproduce in living cells and so require host tissues.

•Influenza virus cultured in chicken embryos

•Japanese encephalitis cultured in the brains of mice

some require human tissue

•Rubella vaccine it is obtained from human foetuses

testing of vaccine

•Exploiting people of developing countries to trial drugs and they don’t understand the risks.

•Animal testing – is it a necessary evil… most vaccines are tested on animals before clinical trials are conducted.

what are the cultural factors with vaccines

religious beliefs - parents with religious beliefs refuse to immunise children

what are economic factors with vaccines

cost of the vaccine - vaccine can be too expensive

commercialisation - the interest of commercial vaccine production may affect use

SU 3.20 antiviral and antibiotic drugs are used for treating infections and differ in their specificity to pathogens

what are antibiotics

drugs used to fight infections of microorganisms such as bacteria NOT viruses.

some bacteria are now resistant to it now

what are broad spectrum antibiotics

antibiotics that affect a wide range of bacteria

what are narrow spectrum antibiotics

antibiotics that target specific types of bacteria only

what do bactericidal antibiotics do

• Kill bacteria by changing the structure of the cell wall / cell membrane or disrupting the action of essential enzymes

• for example Penicillin, Cephalosporin

bacteriostatic antibiotics

• Disrupt protein synthesis and stop bacteria from reproducing

• example actinomycetes

what is multiple drug resistance

• Bacteria which are resistant to multiple strains of antibiotics

• “Super bugs”

• Occurs due to the overuse of antibiotics for prevention rather than treatment or people not finishing the full course of antibiotics.

what is total drug resistance

resistant to all known drugs

how does antibiotic resistance occur

•Natural genetic variation within the bacterial population is high due to high mutation rate of bacteria.

•When treated with antibiotics, some of resistant bacteria survive by chance (small numbers) these produce colonies of antibiotic resistant bacteria.

•If same selection mechanism/antibiotic is used again then there is an increased number of antibiotic resistant bacteria.

•This antibiotic no longer effective and new antibiotic(s) needed.

what are antiviral drugs

drugs used for treating viral infection, as antibiotics are ineffective against viruses.

how do antiviral drugs work

• As a virus enters host cell, infects with virus DNA or RNA and the host cell replicates making more virus particles.

• Antiviral drugs work to inhibit the development of the virus.

• Eg. HIV, herpes, hepatitis B and C, and influenza A and B.

why is it difficult to treat viral infections

the way in which viruses replicate makes it difficult to find drugs that will treat viral infections

because the host cell produces the new virus particles, any drug that interferes with virus replication is likely to be toxic to the host.