From Inoculation to Immunity: A History of Vaccination
Centuries before anyone understood what caused disease, people in several parts of the world had noticed a curious fact: those who survived smallpox never caught it again. Acting on this observation, healers in China, India and the Ottoman Empire developed a deliberate practice now called variolation. A small quantity of matter taken from the sores of a mildly affected patient was introduced into a healthy person, usually through a scratch in the skin or, in one Chinese method, by blowing dried scabs into the nostrils. The aim was to provoke a limited bout of the disease that would leave the recipient protected. It was a gamble. Most who underwent it recovered with lasting immunity, but a minority fell gravely ill, and a few died — a risk families weighed against the far greater danger of the epidemic itself.
Variolation reached western Europe in the early eighteenth century, carried there partly through the efforts of Lady Mary Wortley Montagu, the wife of a British ambassador, who had watched the procedure performed in Constantinople and had her own children treated. Her advocacy met resistance from physicians who distrusted a folk remedy imported from the East, yet the practice slowly gained ground as its statistics proved persuasive: the death rate from variolation was a fraction of that from smallpox caught naturally. Still, the method had obvious drawbacks. Because it used the live smallpox virus, a variolated person could infect others and start a fresh outbreak, and the severity of the induced illness could never be reliably controlled. What was needed was a way to confer protection without exposing anyone to the disease itself.
That way was found, famously, by the English country doctor Edward Jenner. He had heard the rural belief that milkmaids who caught cowpox — a mild ailment picked up from cattle — seemed immune to smallpox. In 1796 he tested the idea directly, taking matter from a cowpox sore and introducing it into a young boy, then later exposing the child to smallpox, which failed to take hold. Jenner named his technique 'vaccination', from the Latin vacca, meaning cow. Its advantage over variolation was decisive: cowpox could not cause a smallpox epidemic, and the illness it produced was trivial. Jenner could not explain why the method worked — the existence of viruses lay a century in the future — but his careful documentation persuaded a sceptical medical establishment, and the practice spread rapidly across Europe and beyond.
For decades vaccination remained a single trick that worked against a single disease, with no theory to extend it. That changed with the work of the French chemist Louis Pasteur, who established that specific microorganisms cause specific diseases. Pasteur discovered, partly by accident, that a culture of the bacteria responsible for chicken cholera lost its power to cause illness when left to age, yet still protected birds injected with it. He grasped the general principle: a weakened, or attenuated, form of a pathogen could train the body's defences without causing serious harm. Applying this insight, he produced vaccines against anthrax in livestock and, most dramatically, against rabies in humans. In tribute to Jenner, Pasteur extended the word 'vaccine' to cover all such preparations, and immunisation became a method that could, in principle, be turned against many diseases rather than one.
The twentieth century turned this principle into a public-health revolution. Advances in growing viruses in the laboratory allowed vaccines to be manufactured in bulk and to a consistent standard, and coordinated campaigns carried them to populations that had never had access to a doctor. Diseases that had killed or crippled children for generations — diphtheria, whooping cough, tetanus, polio — were pushed into retreat across much of the world. The crowning achievement came in 1980, when the World Health Organization declared smallpox, the very disease that had prompted variolation, to have been eradicated from the planet. It remains the only human disease ever to have been deliberately wiped out, a feat made possible because the virus infected only people and because the vaccine was cheap, stable and highly effective.
Vaccine science has continued to change shape. Rather than using whole weakened pathogens, many modern vaccines present the immune system with only a fragment of a microbe, and the newest rely on genetic instructions that prompt the body to manufacture that fragment itself — the approach behind several vaccines developed at unprecedented speed during the coronavirus pandemic. Yet the field's oldest obstacle is not technical but social. From the earliest days of variolation, a share of the public has regarded the deliberate introduction of disease matter with suspicion, and organised resistance to vaccination is almost as old as the practice. Persuading enough people to accept a vaccine, researchers now recognise, can be as difficult as inventing one — and no laboratory breakthrough protects a community that declines to use it.
Reading Passage 1 has six paragraphs, A–F. Choose the correct heading for each paragraph from the list of headings below. Write the correct number, i–ix, next to each paragraph.
- i An observation turned into a deliberate but risky practice
- ii A safer method that could not explain itself
- iii A single success finally given a general principle
- iv The complete disappearance of a disease worldwide
- v A new obstacle created by government funding
- vi Carrying an eastern remedy into a doubtful West
- vii When the greatest challenge is human rather than scientific
- viii The rising economic cost of failed treatments
- ix How immunity is stored within the body
Do the following statements agree with the information given in Reading Passage 1? Write TRUE if the statement agrees with the information, FALSE if it contradicts it, or NOT GIVEN if there is no information on this.
Complete the sentences below. Choose NO MORE THAN TWO WORDS from the passage for each answer.
The Sensing City: Data and the Promise of Smart Urbanism
The phrase 'smart city' has become one of the most fashionable in urban planning, though what it means is often left conveniently vague. At its core is a simple idea: that a city can be run more effectively if it continuously measures itself. Sensors embedded in roads, buildings, pipes and public transport gather a constant stream of information about how the city is functioning — where the traffic is building, how much water is leaking, which rubbish bins are full — and that information is fed to systems that can respond, sometimes automatically. The promise is a city that behaves less like a fixed set of structures and more like a living organism, sensing its own condition and adjusting in real time. Governments and technology companies alike have embraced the vision, and few large cities are now without a 'smart' strategy of some kind.
The practical gains can be substantial. Traffic lights that adjust to the actual flow of vehicles, rather than following a fixed timer, can ease congestion and cut the emissions produced by idling cars. Sensors that report when a bin is full allow collection lorries to be sent only where they are needed, saving fuel and labour. Networks that monitor the electricity grid can balance supply and demand more finely, drawing on renewable sources when they are plentiful. In several cities, systems that detect leaks in the water network have saved millions of litres that would once have drained away unnoticed. Presented as a list, these improvements are undeniably attractive, and they explain much of the enthusiasm with which the smart-city model has been sold to hard-pressed municipal authorities.
None of this works without data, and the appetite for it is enormous. Beyond the fixed sensors, cities increasingly draw on the devices their residents already carry. The location signals from millions of mobile phones can reveal, in aggregate, how crowds move through a district over the course of a day; payment cards trace patterns of spending; cameras equipped with image-recognition software can count pedestrians or read number plates. Enthusiasts describe this as a city that finally knows itself, able to plan on the basis of how people actually behave rather than how planners imagine they do. The richer the data, the argument goes, the better the decisions that can be built upon it.
It is precisely this richness that alarms the model's critics. A system capable of optimising traffic by tracking vehicles is also, unavoidably, a system capable of recording where individuals go and when. Data gathered for one benign purpose can be repurposed for another that was never disclosed, and information that is harmless in isolation can become revealing when combined. A person's movements, purchases and daily routines, assembled from separate streams, amount to a detailed portrait that few would knowingly hand over. The danger, critics warn, is not necessarily a deliberate surveillance state but a gradual, almost accidental erosion of privacy, in which citizens are watched more closely than any previous generation without ever having agreed to it.
A further question concerns who owns and controls all this information. Much of the technology that underpins the smart city is designed, installed and operated by private corporations, which may retain the data their systems generate. This can leave a city dependent on a commercial supplier for the very information it needs to govern itself, and it raises the prospect of public decisions being shaped by companies whose priorities are not those of the electorate. Some cities have responded by insisting that data collected in public spaces belong to the public, and by writing such conditions into their contracts. But the balance of expertise, and often of power, tends to lie with the firms, and the terms on which urban data is gathered are frequently settled with little public debate.
There is also a subtler risk in trusting the data too completely. Any measurement captures some things and misses others, and a city managed by the numbers may quietly privilege whatever is easiest to count. Algorithms trained on past data can entrench the patterns of the past, directing resources towards districts that have always received them and away from those that have not. And a model built around connected devices may overlook the residents least likely to carry them — the poor, the elderly, the homeless — whose needs leave the faintest digital trace. A system that claims to represent the whole city may, in practice, listen most attentively to its most connected citizens.
For all these concerns, few would argue for abandoning the tools altogether; the waste and inefficiency of the unmonitored city are real enough. The more thoughtful voices in the debate call instead for a shift in emphasis — away from technology bought as a finished product and towards decisions made openly, with residents treated as participants rather than as sources of data. A smart city, on this view, is not one stuffed with the most sensors but one that is clear about what it measures, why, and on whose behalf. The technology, in the end, is only as trustworthy as the institutions that direct it.
Choose the correct letter, A, B, C or D.
Look at the following statements and the list of groups below. Match each statement with the correct group, A–D. NB You may use any letter more than once.
- A Enthusiasts of the smart-city model
- B Critics of the model
- C Some city authorities
- D The more thoughtful voices in the debate
Complete the summary below. Choose NO MORE THAN TWO WORDS from the passage for each answer.
Do the following statements agree with the claims of the writer in Reading Passage 2? Write YES if the statement agrees with the claims of the writer, NO if it contradicts them, or NOT GIVEN if it is impossible to say what the writer thinks.
The Deciding Brain: Neuroscience and the Question of Free Will
Few convictions feel more secure than the sense that we author our own actions. When you raise your hand, choose a meal or decide to end a friendship, it seems obvious that you could have done otherwise — that the decision was yours, and that nothing compelled it. This feeling of authorship is so basic that our systems of praise, blame, law and morality are built upon it. Yet the same period that has deepened our faith in science has also produced a picture of the brain that appears to leave no room for it. If every mental event is the product of physical processes obeying the ordinary laws of nature, then a choice is simply the outcome of prior causes — the state of your neurons a moment before, itself the product of earlier states stretching back beyond your birth. On this account the feeling of free choice may be genuine, but the freedom it reports is not.
The debate acquired a sharp empirical edge in the 1980s through a series of experiments by the neuroscientist Benjamin Libet. He asked volunteers to make a simple, spontaneous movement — flexing a wrist — whenever they felt the urge, and to note the exact moment at which they became aware of the decision to move. Meanwhile he recorded electrical activity in their brains. What he found was striking: a distinctive build-up of activity, which he called the 'readiness potential', began several hundred milliseconds before the volunteers reported being conscious of any intention to act. The brain, it appeared, had begun preparing the movement before the person knew they had decided on it. To many observers the implication was disturbing: the conscious will arrives too late to be the true cause of what we do, and is at best a spectator informed after the fact.
For those already inclined to doubt free will, Libet's results seemed to settle the matter. If the brain commits to an action before awareness of deciding appears, then the experience of choosing is a kind of story the mind tells itself afterwards, a narrative pasted over a process that has already run its course. Some writers have drawn bold conclusions from this and related findings, arguing that free will is an illusion and that we should reshape our institutions accordingly — softening the idea of blame, for instance, since a wrongdoer could not ultimately have acted otherwise. The appeal of the position is its apparent consistency with a thoroughly physical view of the mind: it asks us to take seriously the thought that we are, in the end, biological machines.
The bolder claims, however, have met sustained resistance, much of it aimed not at Libet's data but at what the data are taken to mean. Critics note that flexing a wrist on no particular grounds is nothing like the deliberate, reasoned decisions — whether to take a job, or to tell the truth — that we most care about when we speak of freedom; a finding about arbitrary twitches may simply not generalise. Others question whether the exact timing of a fleeting, private awareness can be reported with the precision the argument requires. More fundamentally, some philosophers argue that the whole experiment rests on a confused picture, one that imagines a conscious self standing apart from the brain and issuing commands to it. If, instead, the deciding self simply is the relevant brain activity, then the readiness potential is not something that pre-empts the decision but part of the decision being made.
Running beneath the experimental dispute is an older disagreement about what 'free will' should even be taken to mean. One long tradition holds that freedom requires the ability to have done otherwise in exactly the same circumstances — a power that determinism, if true, would deny us. But another, known as compatibilism, rejects this demand as confused. What matters for freedom, on this view, is not whether an action was caused but how: an action is free when it flows from the agent's own desires and reasoning, and is unfree when it is coerced or compelled from outside. A person choosing calmly among options is free in every sense worth wanting, even if that choice, like everything else, has causes. For compatibilists, the neuroscience changes nothing, because it was never the existence of causes that threatened freedom in the first place.
Whichever interpretation one favours, the stakes are considerable. Much of criminal law assumes that people can be held responsible for what they choose to do, and a genuine demonstration that no one ever really chooses would unsettle that assumption profoundly. Some argue that abandoning the notion of ultimate responsibility need not mean abandoning punishment — we might still restrain the dangerous and try to reform the correctable — but it would shift the justification from desert to consequences, from what an offender deserves to what protects society. Others worry about the effect of the message itself: experiments have suggested that people who are persuaded their choices are illusory may behave slightly less honestly, as though the belief in freedom, whatever its truth, does useful work.
What, then, has neuroscience actually shown? Rather less, on reflection, than the headlines suggest. It has demonstrated that unconscious brain processes precede and shape our conscious decisions — a genuine and important finding, but one that overturns only a particular, and perhaps naive, idea of free will: the notion of a conscious self hovering above the brain, uncaused and in full command. It has not shown, because it cannot, that our reasoned choices play no role in what we do, still less that the concepts of responsibility on which social life depends must be discarded. Whether we possess free will may turn out to depend less on any experiment than on which of several defensible meanings we attach to the words — a question that brain research can inform, but not, by itself, decide.
Reading Passage 3 has seven paragraphs, A–G. Which paragraph contains the following information? Write the correct letter, A–G. NB You may use any letter more than once.
- A Paragraph A
- B Paragraph B
- C Paragraph C
- D Paragraph D
- E Paragraph E
- F Paragraph F
- G Paragraph G
Do the following statements agree with the information given in Reading Passage 3? Write TRUE, FALSE or NOT GIVEN.
Choose the correct letter, A, B, C or D.
Answer the questions below. Choose NO MORE THAN THREE WORDS from the passage for each answer.