[Maximum number: 2]

The Zika virus is a pathogen that can infect human cells.

(a)

Zika virus vaccines have been developed by scientists.

One of the vaccines contains small proteins from the Zika virus.

[ 2 ]

(i)

Explain how a vaccination programme may limit the spread of Zika virus disease through a population.

[ 2 ]

[Maximum number: 2]

Fig. 3.1 is an electron micrograph of a type of B-lymphocyte called a plasma cell.
Plasma cells secrete antibody molecules.

Fig. 3.1

(a)

State two reasons why the vaccination programme was successful in eradicating smallpox.

1

2

[ 2 ]

[Maximum number: 3]

Tuberculosis (TB), influenza and polio are examples of infectious diseases.

(a)

Polio is a serious viral disease affecting young children. In 1996, polio caused paralysis in more than 75000 children across Africa. A long-term vaccination programme allowed the World Health Organization (WHO) to declare that Africa was largely free of polio in 2020.

[ 3 ]

(i)

Explain how vaccination programmes can help to control the spread of infectious diseases, such as polio.

[ 3 ]

[Maximum number: 1]

The World Health Organization (WHO) set a target to eradicate polio, using vaccination, by the year 2000. However, cases are still being reported in some parts of the world after this date.

What explains these new cases of polio?
1 Some parts of countries are difficult to reach because of poor transport or wars.
2 There is not enough research to develop more effective vaccines.
3 Records of vaccinated and unvaccinated people are incomplete.

1 only

1 and 2 only

1 and 3 only

2 and 3 only

Which statement explains how a vaccination programme can control the spread of an infectious

[Maximum number: 1]

A successful vaccination programme provides a level of immunity where the majority of a population is protected.

There are several factors that can affect the success of a vaccination programme.
Which row correctly shows the factors that can affect the success of a vaccination programme?

frequent mutation of the pathogen

vaccination from eight weeks old

pathogen is able to invade T-cells

booster vaccinations needed frequently

✓

key
✓ = affects
$\boldsymbol{\chi}=$ does not affect

The vaccination programme for smallpox was a medical success story which resulted in the