The image shows the progress of infection when damaged human skin comes into contact with Human Papillomavirus, or HPV.
It can be 6-12 months before HPV antibodies can be detected in the blood of an individual with a HPV infection. Use the information in the image to suggest why this is.
There is a vaccination for HPV which is routinely given to teenage girls, as it is thought to offer future protection against cervical cancer. The standard procedure is for each girl to receive three doses of the vaccine for full immunity, although there is some discussion about the optimum number of doses.
The graph below shows antibody production after different doses of HPV vaccine in teenage girls.
A student concluded from the data that it didn’t matter whether girls were given two doses of vaccine or three. Evaluate this conclusion.
HPV vaccines provide protection against cancer by preventing the virus from causing mutations in infected cells. Current medical advances in vaccine technology mean that researchers hope that it will soon be possible to vaccinate people against cancer cells themselves.
The image shows some of the changes that can take place when a cell becomes cancerous.
Use the image to suggest how a vaccine could be effective against the development of cancer.
It is hoped that one day, cancer vaccinations may exist which prevent cancer rather than for treatment of cancer. Trials to test these new vaccines will be put through a rigorous development procedure as follows:
Research and development stage using bioinformatics
Non-clinical trials in the laboratory (testing efficacy and toxicity)
Whole organism testing on animals (testing efficacy, toxicity and dosage)
Clinical trials on adult human volunteers
Compare and contrast these modern methods of vaccine development with those used by Edward Jenner in the development of the smallpox vaccine.
Development of an Ethics Research Committee marks a key change in the procedures involved in the development of new drugs, including vaccines, however, there are still issues associated with the modern methods described in part d).
Suggest what ethical issues may be associated with these procedures.
HIV infects human T-cells by binding to a cell surface receptor called CD4. This binding causes a shape change in the viral surface glycoproteins, enabling the virus to enter the host cell.
A new treatment for HIV involves a monoclonal antibody called Ibalizumab, the action of which is shown in the diagram below.
Suggest how Ibalizumab works as a treatment for HIV.
