IELTS Academic Reading Practice Test 318

For much of the early twentieth century, polio was the disease that parents in Europe and North America feared more than any other. Caused by a virus that spreads through contaminated water and food and through contact with infected people, it usually produced nothing worse than a mild illness resembling flu. In a small proportion of cases, however, the virus attacked the nervous system and destroyed the cells that control muscles, leaving a child paralysed, sometimes permanently, and in the worst cases unable to breathe unaided. Epidemics arrived with the summer and filled hospital wards with patients in iron lungs, airtight metal cylinders that kept the chest moving by means of changes in pressure.

The most famous patient was Franklin D. Roosevelt, who was diagnosed with polio in 1921, at the age of thirty-nine, and never regained the use of his legs. Roosevelt bought a run-down resort at Warm Springs in Georgia, where the warm mineral water seemed to help sufferers, and in 1938 he helped to found the National Foundation for Infantile Paralysis. Its fundraising campaign, the March of Dimes, asked ordinary Americans to send small change to the White House, and millions did so. The money paid for research and for the care of patients, and the foundation's publicity made polio the most feared disease in the country.

Three types of poliovirus exist, and infection with one gives no reliable protection against the others, a fact that complicated every attempt at vaccination. The virus enters through the mouth, multiplies in the throat and intestine and is shed in the faeces for several weeks; where sanitation is poor it spreads easily, yet most infections pass unnoticed. Because paralysis followed perhaps one infection in a hundred, a vaccine could only be tested by giving it to very large numbers of children and watching whether they developed the disease.

Jonas Salk, a young American researcher at the University of Pittsburgh, took the opposite approach to most of his rivals. Instead of weakening the virus until it could no longer cause illness, he killed it with formalin, a chemical that destroyed its ability to infect while leaving its outer shape intact so that the immune system would learn to recognise it.

Killed vaccines had a poor reputation, because an earlier attempt against polio in the 1930s had gone badly wrong, and many scientists doubted that his version would work. His team still had to work out how to grow the virus in monkey kidney tissue, how to be sure that each batch was genuinely dead, and how to combine three types in one injection.

The trial that settled the question was organised by the National Foundation and was, at the time, the largest medical experiment ever conducted. In 1954, some 1.8 million schoolchildren in the United States took part: about 400,000 received the vaccine, 200,000 received a placebo, and the remainder were observed without being injected at all. The results were announced on 12 April 1955, exactly ten years after Roosevelt's death, and showed the vaccine to be effective. Within days several pharmaceutical companies were licensed to produce it, and demand exceeded supply for months.

Six firms were licensed to make the vaccine, and one of them, Cutter Laboratories of California, released batches that still contained live virus. Because each batch was grown in bulk, a single failure of inactivation could affect hundreds of doses, and within weeks about 200 children were paralysed and ten died. The episode, remembered as the Cutter incident, shook public confidence and halted the programme for a time. It also led to stricter federal inspection of vaccine production, and gave Sabin's supporters a powerful argument.

Albert Sabin, a Polish-born American researcher, had been working on a live but weakened vaccine since the 1930s. His aim was to produce an infection that would mimic natural immunity without causing disease, and he tested weakened strains on himself and on volunteers. A key advantage was that the vaccine could be swallowed rather than injected, and that the weakened virus multiplied in the intestine and could be passed on to others, so that immunity might spread through a community. Because the Soviet Union was willing to use it while American regulators hesitated, trials involving millions of children took place there in 1959, and the oral vaccine was licensed in the United States in 1961.

Salk's vaccine had one advantage that its rival lacked: it could not cause polio at all, whereas the weakened virus in the oral vaccine causes paralysis in roughly one recipient in every few million doses. Richer countries that had eliminated the disease therefore tended to prefer the injected vaccine, while the oral version, cheaper, easier to give and better at blocking transmission, dominated the global campaign. The two men were rivals, and the press portrayed their disagreement as a personal quarrel, although both refused to patent their vaccines and neither made money from them.

In 1988 the World Health Organization and its partners launched a campaign to eradicate polio entirely, when the virus was circulating in more than 125 countries and an estimated 350,000 people were paralysed each year. Two of the three types have since been declared eradicated: type 2 in 2015 and type 3 in 2019. Africa was certified free of wild polio in 2020, but transmission of type 1 has continued in Afghanistan and Pakistan, where reaching children in areas of conflict has proved the most stubborn obstacle of all.

An allergy is a reaction of the immune system to a substance that is harmless in itself. The substances that provoke it, called allergens, are usually proteins: pollen from grasses, trees and weeds; the droppings of house dust mites; the saliva and skin flakes of cats; the proteins in peanuts, eggs, milk and shellfish; and certain drugs. Allergies are common, and their frequency appears to have risen in many countries since the 1960s, although estimates vary widely and the reasons are still argued about.

The first stage of an allergic reaction is sensitisation, and it can take place without the person noticing anything at all. When an allergen enters the body, it is taken up by dendritic cells, which carry fragments of it to lymph nodes and present them to other immune cells. In someone who is predisposed to allergy, this process leads certain B cells to produce a class of antibody called immunoglobulin E, or IgE, which was not identified until the 1960s. These antibodies attach themselves to the surface of mast cells, which are found in the skin, the lining of the airways and the gut, and there they may remain for years, armed but silent.

The second stage occurs the next time the same allergen appears. It binds to several IgE molecules at once, drawing them together, and this cross-linking is the signal for the mast cell to release the contents of its granules into the surrounding tissue. The most important of these chemicals is histamine, which widens blood vessels and makes their walls leaky, producing redness, swelling and itching, and which also causes smooth muscle in the airways to contract. Other substances released at the same time, including leukotrienes and prostaglandins, prolong and intensify the response. The result, depending on where it happens, is sneezing and a streaming nose, or wheezing, or a rash, or vomiting and diarrhoea. In the most severe form, anaphylaxis, blood pressure falls sharply and the airway can close.

The form an allergy takes depends largely on the route by which the allergen enters. Pollen and dust mite droppings are inhaled, so they produce hay fever and asthma; foods are eaten, so they cause swelling of the lips, vomiting and, occasionally, anaphylaxis; drugs and insect stings reach the bloodstream directly and are the most likely to cause a severe reaction. Eczema, in which the skin becomes dry, cracked and inflamed, is also driven by an allergic-type immune response, though in this case the trigger is often unclear.

Diagnosis begins with the history: what the patient ate, touched or breathed in, and how soon afterwards the symptoms appeared. Skin prick tests introduce tiny amounts of suspected allergens into the skin of the forearm; a raised, itchy wheal within about fifteen minutes suggests that IgE against that substance is present. Blood tests measure the same antibodies. Neither test is conclusive on its own, because a positive result is common in people with no symptoms, and the most reliable method remains the oral food challenge, in which the food is eaten in gradually increasing amounts under medical supervision.

The most influential explanation for the rise in allergies was proposed in 1989 by David Strachan, an epidemiologist, who noticed that hay fever was less common in children with several older siblings. His suggestion, soon labelled the hygiene hypothesis, was that infections in early childhood, spread by messy contact with brothers and sisters, helped to steer the developing immune system away from allergic responses. There is supporting evidence: children who grow up on farms, in close contact with animals and their microbes, tend to have fewer allergies than children in cities. But the hypothesis in its original form fits the data poorly: many childhood infections show no such protective effect, and allergies have continued to rise in countries where family sizes are not changing.

Graham Rook has argued for a revised version, sometimes called the old friends hypothesis, in which the immune system needs exposure not to infections but to harmless microbes from soil, animals and other people, in order to learn tolerance. Others have pointed to changes in diet, to the use of antibiotics in infancy, to delivery by caesarean section, to vitamin D and to the loss of biodiversity. All of these are plausible, and several may matter; none has been shown to explain more than a fraction of the trend.

Treatment falls into two parts. The first is to relieve symptoms: antihistamines block the histamine receptor and reduce sneezing and itching, corticosteroid sprays calm inflammation in the nose and airways, and adrenaline, injected into the muscle, reverses the collapse of blood pressure in anaphylaxis. The second is to change the immune response itself. Immunotherapy has been given for hay fever for more than a century: increasing doses of the allergen are injected under the skin, or placed under the tongue, until the patient tolerates it. More recently, oral immunotherapy for peanut allergy has been shown to raise the amount that patients can safely eat; one product was approved for children in the United States in 2020.

None of these treatments is a cure. Patients on immunotherapy must usually keep avoiding the food, carry adrenaline and accept that reactions remain possible, and the protection fades if treatment stops. Why some children outgrow allergies while others keep them for life is still largely unexplained, and researchers are looking at the gut bacteria of those who do.

Few public institutions are defended with as much emotion as the British National Health Service. Since 1948 it has been financed almost entirely from taxation, and at the moment of use most care has been free: no bill at the end of a consultation, no calculation about whether an appointment can be afforded. Most other rich countries arrange things differently, requiring patients to pay a share of the cost while protecting the poorest with exemptions and annual limits. Which model produces better care, and greater fairness, is a question that deserves more attention than it usually receives.

When Aneurin Bevan, the minister responsible, opened the service in 1948, he insisted that treatment should be available to everyone and paid for from general taxation rather than insurance. The principle did not survive intact for long. In 1951 the government announced charges for spectacles and dentures, and Bevan resigned in protest, warning that a service which asked patients for money would lose the support of the middle classes and become a poor service for the poor. His prediction captures something real: the political strength of a universal service depends on everyone using it.

The Beveridge report of 1942, which set out the blueprint for the post-war welfare state, had assumed something similar. Beveridge identified disease as one of five giants to be attacked, and he proposed a comprehensive health service financed by the national insurance contributions of workers, so that the cost would be shared across a lifetime rather than billed at the moment of illness.

Economists have long argued that medical care is not a market like any other. In a celebrated essay published in 1963, Kenneth Arrow pointed out that patients cannot judge what they are buying, that demand is unpredictable and often urgent, and that the person who sells treatment also decides what treatment is needed. Under such conditions competition does not reliably deliver either efficiency or fairness, and insurance, public or private, becomes necessary. The argument is usually deployed in support of public funding, but it cuts both ways: if the market cannot discipline costs, another mechanism must.

That is where charges come in. Their advocates argue that a service that appears free at the moment of use will be over-used: patients consult doctors about minor complaints, miss appointments and resist discharge from hospital because there is no reason not to. A modest charge, on this view, reminds people of the cost of what they receive, raises revenue and helps to manage waiting lists. Some health economists add that competition between providers only works if money follows the patient, which requires a price.

Evidence about what charges do is thinner than either side's confidence suggests, but two American studies are often cited. In the RAND Health Insurance Experiment of the 1970s, families were assigned at random to insurance plans that required them to pay different shares of their bills. Those who paid more used substantially less care, but the reduction fell on necessary treatment as well as unnecessary, and while the average participant's health hardly changed, poorer and sicker people did worse. The Oregon experiment, which began in 2008, offered Medicaid coverage to low-income adults by lottery. Those who gained it used more health care, were less likely to face financial hardship and were less depressed, yet after two years measures such as blood pressure and cholesterol had not improved measurably.

Both studies hint at the real problem with charges, which is that the patients most likely to be deterred are those who most need care. A charge that seems trivial to a healthy professional may be decisive for someone on a low income managing several conditions. The World Health Organization has repeatedly warned that direct payments push households into poverty and discourage people from seeking help early, so that conditions are treated later, in hospital, at far greater expense. A system that saves money on consultations may spend it on emergency admissions.

It is also worth being honest about the phrase 'free at the point of use'. No health system is free in that sense: care is limited by budgets, staff and equipment, so the question is how it is rationed, whether by waiting lists, by clinical criteria or by price. Most European countries require patients to pay something for prescriptions or consultations, usually with an annual ceiling and exemptions for children and for people with long-term illnesses. The British service has never covered everything either: charges for prescriptions, dentistry and spectacles have existed for decades, and they are levied in some parts of the United Kingdom and not in others.

My own view is that the case for keeping essential care free at the point of use is strong, and Bevan was right about the politics as well as the ethics: a service used by everyone, including the wealthy and the vocal, is more likely to be well funded. Charges have a place only at the margins, for services whose use is genuinely a matter of choice. Any charge needs a low annual cap and generous exemptions, since a fee that stops a patient with chest pain from seeking help is not a saving but a cost postponed. The question that matters is not whether health care should be free, but which care, for whom, and who pays in the end.