1.1. In the UK babies are routinely vaccinated against pathogens such as measles viruses and meningococcal group B bacteria. Babies are given two or three separate vaccinations against these diseases at regular intervals before their third birthdays.

Explain why more than one vaccination is offered for each disease.

1.2. Fig. 1 shows the incidence of invasive meningococcal disease in the UK from 2010 to 2020. The vaccine for meningococcal B infections was introduced to the UK in 2015.

Fig.1

(i) Explain how vaccination works to produce the downward trend shown in Fig. 1. 

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(ii) Suggest a reason for the data shown in 2018/19.

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1.3. Routine vaccination of babies ensures that as many people as possible are vaccinated. Suggest how this protects the UK population against pathogens such as measles viruses and meningococcal bacteria.

1.4. An expectant mother is concerned about the health of her unborn baby after she has been infected with a common influenza virus (the flu). Her doctor tells her there is no need to be concerned. 

Explain how a foetus is protected against the pathogens that infect its mother during pregnancy.