Unit 17 · The Future of Medicine, and Capstone

In December 2020, nurses in the United States began giving the first COVID-19 vaccines. Two of the first vaccines used a new method called mRNA. The idea had taken researchers about thirty years to make work. The vaccines were built within days once the virus’s genetic code was shared, and then they were tested in large trials with tens of thousands of volunteers.

Your cells use messenger RNA, or mRNA, as a working copy of a gene. The copy carries instructions to the cell’s protein-making machinery. An mRNA vaccine delivers instructions for just one protein, the spike protein on the outside of the coronavirus. Cells make that protein for a short time. The mRNA breaks down within days, and it does not enter the cell’s nucleus or change DNA.

The immune system sees the spike protein and treats it as foreign. It makes antibodies, proteins that stick to the spike, and it trains memory cells. If the real virus arrives later, the body is ready faster. Hungarian-born scientist Katalin Karikó and American scientist Drew Weissman found a way to change mRNA so it did not set off too much inflammation. They shared the 2023 Nobel Prize in Physiology or Medicine for that work.

Bacteria have enemies too: viruses that attack them. Many bacteria keep small pieces of old virus DNA in their own DNA, like mug shots. If the same virus returns, the bacterium makes a guide that matches it and sends a cutting protein, such as Cas9, to cut the invader’s DNA. Scientists named this system CRISPR, from the repeating pattern of DNA where the mug shots are stored.

In 2012, Jennifer Doudna of the University of California, Berkeley, and Emmanuelle Charpentier, a French microbiologist, showed that this system could be turned into a tool. Scientists can write a guide RNA that matches almost any stretch of DNA they choose. The guide leads Cas9 to that spot, and Cas9 cuts. The cell then repairs the cut, and researchers can use that repair to switch a gene off or change it. Doudna and Charpentier won the 2020 Nobel Prize in Chemistry.

Victoria Gray’s treatment shows how this works in medicine. Scientists did not fix the sickle cell gene itself. They cut a switch gene that normally turns off fetal hemoglobin after birth. With that switch cut, her blood cells made fetal hemoglobin again. This is called somatic editing: it changes cells in one patient’s body, and those changes are not passed to children.

In November 2018, a Chinese scientist named He Jiankui announced that twin girls had been born from embryos he had edited with CRISPR. He said he wanted to protect them from HIV. Scientists around the world objected. The work had not been openly reviewed, the risks were unknown, and the edits could pass to the girls’ own children. A Chinese court later sentenced him to prison for illegal medical practice.

The key difference is between somatic editing and germline editing. Germline editing changes eggs, sperm or embryos, so every cell of the future person carries the change, and so can that person’s children. Many scientists and ethicists say germline editing should not be used to start pregnancies now. They point to unknown safety risks and to the fact that future people cannot give consent, which means agreeing after understanding the risks.

Others argue that one day germline editing might prevent serious inherited diseases for a whole family line. There are also worries about fairness: if editing becomes a costly option for the wealthy, it could widen gaps in health. These are real, open debates. Most countries restrict germline editing, and international scientific meetings have called for strict limits and broad public discussion before any use.

Two women have breast cancer. Under the microscope their tumors look alike. But a lab test shows that one tumor has large amounts of a protein called HER2 on its cells. For her, doctors can add a drug called trastuzumab, which targets HER2. The U.S. Food and Drug Administration approved it in 1998. For the other woman, whose tumor lacks extra HER2, that drug would not help.

This is personalized medicine, sometimes called precision medicine. Instead of one treatment for everyone with the same disease name, doctors use tests to find which group a patient belongs to. It became much more practical after the Human Genome Project finished reading nearly all of human DNA in 2003. Since then, reading a person’s genes has become far faster and cheaper.

One branch is pharmacogenomics, the study of how genes affect a person’s response to medicines. Some people’s livers break down certain drugs quickly, and others slowly. A gene test can help a doctor choose a medicine or a safer starting amount. Personalized medicine is growing, but many tests are costly, and most studies so far have included mostly people of European ancestry, so results may not fit everyone equally well.

People with diabetes can slowly lose vision from damage to the blood vessels in the retina, the back of the eye. Catching it early helps. In 2018 the U.S. Food and Drug Administration authorized a system called IDx-DR. A trained staff member photographs the retina in a regular clinic. Software then decides whether the patient should see an eye specialist, without a specialist first reading the picture.

This software is a kind of artificial intelligence, or AI. It was built through machine learning: a computer program studied a very large number of labeled eye photographs until it could sort new ones. Similar tools now help flag possible problems on X-rays, skin photos and heart tracings. Many work best as a second pair of eyes that points a doctor toward something to check.

AI has real limits. A program learns only from the data it is given. If most training images came from one group of people, it may make more mistakes with others; this is called algorithmic bias. A program can also be confidently wrong. For these reasons, health bodies stress testing tools in real clinics, protecting patient privacy, and keeping trained people responsible for decisions.

In spring 2020, the COVID-19 pandemic closed many clinic waiting rooms. Almost overnight, a large share of doctor visits in the United States moved to video and phone calls. A teenager could talk with a counselor from her bedroom. An older farmer could review blood-pressure readings with a nurse without driving two hours to town.

This is telehealth: health care delivered at a distance using technology. It includes video visits, phone calls, secure messages and remote monitoring, in which a device at home, such as a blood-pressure cuff or glucose meter, sends readings to a care team. Telehealth can save travel time, reach rural areas with few specialists, and make follow-up visits easier to keep.

Telehealth also has limits. A doctor cannot listen to lungs or press on a sore belly through a screen, so some problems still need an in-person exam. Not every home has fast internet, a private room or a device, a gap often called the digital divide. Many clinics now mix the two: video for check-ins and talk therapy, and in-person visits for exams, tests and emergencies.

When Alexander Fleming accepted the Nobel Prize in 1945 for discovering penicillin, he gave a warning. If people took too little penicillin, or took it when it was not needed, surviving bacteria could become resistant. He had already seen this happen in his laboratory. Within a few years, doctors began finding resistant bacteria in hospitals.

Antibiotic resistance happens through natural selection. In a large group of bacteria, a few may carry a gene change that helps them survive a drug. The antibiotic kills the others, and the survivors multiply. Bacteria can even pass resistance genes to one another. Antibiotics work against bacteria only; they do nothing against viruses, such as those that cause colds and flu.

The U.S. Centers for Disease Control and Prevention reported in 2019 that more than 2.8 million antibiotic-resistant infections happen in the United States each year, and more than 35,000 people die from them. Helpful steps are known. Take antibiotics only when a clinician prescribes them. Take them exactly as directed. Wash hands and keep vaccines up to date. This practice of careful use is called antibiotic stewardship.

In Japan, one of the countries with the longest life expectancy, it is common to meet healthy people in their eighties still gardening and walking to the market. Around the world, the same shift is under way. Better sanitation, vaccines, safer childbirth and treatment for heart disease mean more people reach old age than ever before.

The World Health Organization estimates that about 1 billion people were aged 60 or older in 2020. It projects about 1.4 billion by 2030 and about 2.1 billion by 2050. This is called population aging. Older adults are more likely to live with chronic conditions, illnesses that last a long time, such as arthritis, heart disease, diabetes or dementia. Many have more than one.

Aging well is not only about treating disease. The WHO speaks of healthy aging: helping people keep doing what they value. Regular movement, social contact, good hearing and vision care, and fall prevention all help. Health systems will need more geriatric specialists, nurses, home-care workers and family caregivers, and communities will need safe sidewalks, transit and places to gather.

Follow one patient, a man who falls from a ladder. Emergency medical technicians, or EMTs, reach him first. They check his breathing, protect his neck and drive him to the hospital. EMT training is a course of a few months, followed by a certification exam. Paramedics train longer and can give more medicines.

At the hospital, a registered nurse watches him hour by hour, gives medicines and explains what is happening. Registered nurses earn a two-year associate degree or a four-year bachelor’s degree and then pass a national licensing exam, the NCLEX-RN. A physician diagnoses his broken hip. Physicians finish four years of college, four years of medical school, and then residency, supervised hospital training that lasts about three to seven years.

Before he goes home, a pharmacist checks that his new medicines are safe together. Pharmacists earn a Doctor of Pharmacy degree and pass licensing exams. A physical therapist helps him walk again; physical therapists earn a doctoral degree, usually three years after college. Each of these jobs requires a license, official permission from a state to practice.

Not every health worker sees patients one at a time. Some are researchers. Katalin Karikó spent decades in laboratories studying mRNA before it became a vaccine. Research careers usually need a doctoral degree, such as a PhD or MD, and years of work in a lab or clinic. Research assistants and lab technicians help run studies with less schooling.

Public health workers protect the health of whole communities. They track outbreaks, inspect restaurants, test water and run vaccination drives. When a city health department traces the spread of measles, public-health workers are doing the detective work. Many hold a Master of Public Health degree, and community health workers often begin with shorter training and deep ties to the neighborhoods they serve.

Health care also includes other licensed paths. An acupuncturist practices a therapy from Traditional Chinese Medicine. Most U.S. states license acupuncturists; they usually complete a master’s-level program and a national certification exam. Other careers include dietitians, respiratory therapists, occupational therapists, medical interpreters and dental hygienists. Rules differ from state to state, so a smart first step is to check your own state’s licensing board.

Look at three possible questions. Does tai chi prevent falls in older adults? How did Bangladesh reduce deaths of young children? Should health insurance cover acupuncture for back pain? Each one names a real situation, and each can be studied with published evidence. That makes each a good research question: a clear question that evidence can help answer.

Some questions are too big. "Is traditional medicine good?" covers thousands of practices and cannot be answered in one project. Narrow it by naming who, what and which result. "Does tai chi reduce falls in adults over 65?" is focused. Some questions are about facts, and some are about values. "Should insurance cover it?" needs facts about benefit and cost, and also a judgment about fairness.

Start with something that matters to you: a family remedy, a sport injury, a news story, or a health gap in your community. Write the question in one sentence. Then ask three things. Can I find reliable evidence on it? Is it narrow enough? Could the answer surprise me? If the answer to the last one is no, you may be trying to prove something rather than find out.

Doctors who search for evidence often use a pattern called PICO. P is the population, the people the question is about. I is the intervention, the treatment or action being tested. C is the comparison, what it is measured against. O is the outcome, the result that matters. Writing each part down turns a vague idea into a searchable question.

Try it on falls. P: adults over 65 living at home. I: a tai chi class twice a week. C: no class, or a different kind of exercise. O: the number of falls in a year. Now the question reads, "In adults over 65, does twice-weekly tai chi reduce falls compared with no class?" Those words are also the search terms you will type into a database.

The outcome deserves the most thought. A study might show that tai chi improves balance on a lab test. That is useful, but the result that matters most to an older person is not falling and staying independent. Look for studies that measure outcomes people actually care about, such as falls, pain, days of school missed or survival.

Nadia’s grandmother’s story is a kind of evidence, called an anecdote: one person’s experience. Anecdotes matter. They often start good questions. But they cannot tell whether a result came from the remedy, from time, or from chance. Stronger kinds of evidence are designed to separate those causes.

A randomized controlled trial, or RCT, assigns people by chance to a treatment group or a comparison group and then compares outcomes. Because chance decides who gets what, the groups start out alike. An observational study watches what people already do, such as comparing people who drink green tea with people who do not. It can find links, but people who choose green tea may differ in other ways too.

A systematic review gathers every good study on one question, judges their quality, and often combines their results. The Cochrane Collaboration, founded in 1993, is a well-known group that publishes such reviews. For most treatment questions, a recent systematic review of RCTs is the strongest place to start. Some questions, such as rare side effects, depend more on large observational studies.

When you search a health question online, the first results may be ads or sellers. Start instead with trusted bodies. The World Health Organization (WHO) sets global guidance. The U.S. Centers for Disease Control and Prevention (CDC) tracks disease and publishes prevention advice. The National Institutes of Health (NIH) funds and reports medical research.

For traditional and complementary practices, the NIH’s National Center for Complementary and Integrative Health, or NCCIH, publishes plain-language pages. They cover acupuncture, tai chi, yoga, herbs and more. Each page says what the tradition teaches, what research has found, and what safety concerns exist. PubMed, a free database from the National Library of Medicine, lists millions of research articles and lets you filter for systematic reviews.

Many research articles are peer-reviewed. That means other experts read the study before publication and asked for fixes. Peer review catches many errors, but not all, so one study is never the final word. Also note the date. A 2024 review may include trials that a 2010 page never saw. Write down every source’s author or body, title and year as you go.

A website says a tea "cures diabetes naturally in 30 days" and "doctors don’t want you to know." A second site sells a new pill with a smiling scientist and a chart with no labels. Both show red flags: signs that a health claim may not be trustworthy. Red flags can show up for modern products and for traditional ones alike.

Common red flags include promises to cure serious diseases, claims that one product fixes many unrelated problems, stories instead of studies, and warnings not to trust your doctor. Ask who made the page and whether they profit. That is a conflict of interest: a reason someone might favor a result, such as selling the product. Studies should disclose conflicts, and readers should notice them.

Checking a claim does not mean mocking it. Many traditional remedies have been studied fairly, with mixed results. The goal is to ask the same fair questions of every claim: What is the evidence? Who says so? How strong is it? If a claim involves a serious illness, talk with a doctor, nurse or pharmacist before changing any treatment.

In 1747, aboard the British ship HMS Salisbury, the Scottish surgeon James Lind cared for sailors sick with scurvy. He chose twelve with similar symptoms and gave pairs of them different added foods or drinks, such as cider, vinegar, seawater, or oranges and lemons. The pair given citrus fruit recovered fastest. Lind’s small study is often called one of the first controlled trials, because he compared groups side by side.

Modern fair tests add more. A control group gets no treatment, a usual treatment or a placebo, a look-alike with no active ingredient. Random assignment decides who goes where. Blinding means patients, and often the researchers, do not know who got the real treatment. That matters because expecting to feel better can change how people feel and how researchers judge results.

Some treatments are hard to blind. You cannot hide from someone that they are doing tai chi. Researchers then compare tai chi with another activity, such as stretching, and use judges who do not know the groups to count the outcome. For acupuncture, some trials use a sham, such as needles placed at points the tradition does not use, and the choice of sham itself is debated.

In a park in Chicago’s Chinatown, a group of older adults moves slowly together through a set of flowing steps. This is tai chi, a practice that grew from Chinese martial arts. In Traditional Chinese Medicine, tai chi is understood to help the smooth flow of qi, the tradition’s idea of vital energy, while calming the mind and building balance.

Falls are a leading cause of injury for older adults, so researchers have tested whether exercise can help. A 2019 Cochrane systematic review by Catherine Sherrington and colleagues gathered trials of exercise for older people living in the community. It found that balance and functional exercise reduces the rate of falls, and that tai chi may reduce it too, though the evidence for tai chi was less certain.

Notice how two views fit together here. Science does not measure qi, so it cannot confirm the tradition’s explanation. But it can measure falls, and on that outcome the evidence is encouraging. The CDC includes tai chi-based balance programs among options to help prevent falls. A fair capstone would state both points clearly and respectfully.

In Bangladesh in the 1980s, health workers went village to village teaching families to mix clean water, sugar and salt. This is oral rehydration solution, or ORS. Diarrhea can drain water and salt from a child’s body quickly, and ORS replaces them. Trials in Bangladesh and India helped show it works, and it became one of the most important child-health tools in the world.

Worldwide, the number of children who die before age five has fallen sharply. The UN Inter-agency Group for Child Mortality Estimation reports about 12.8 million such deaths in 1990 and about 4.9 million in 2022, even as the world’s population grew. The under-five mortality rate, deaths per 1,000 live births, fell by more than half.

No single cure did this. Vaccines, ORS, bed nets against malaria, clean water, skilled birth attendants, better nutrition and girls’ education all played parts. Many of these steps were tested in trials and scaled up by governments and community health workers. A capstone on this question would compare several causes and ask which evidence is strongest for each.

Nadia’s final page had three headings. Under What is known, she wrote that a Cochrane review found honey may ease children’s cough symptoms more than no treatment, and that honey must never be given to babies under one. Under What is not known, she wrote that the trials were small and short. Under My conclusion, she said honey is a reasonable, low-cost comfort for coughs in children over one, while serious or lasting coughs need a doctor.

This structure keeps you honest. The certainty of evidence describes how sure we can be that a result is true. Cochrane and many guideline groups rate certainty as high, moderate, low or very low. Use their words. "May help" fits low certainty; "helps" fits high certainty. Never make a finding sound stronger than the evidence.

Where a question is contested, describe the main views fairly. For example, experts disagree about whether acupuncture’s benefits for some kinds of back pain come from the needling itself or from the care and expectation around it. Say that. Then state your own conclusion, with your reasons, and say what new evidence would change your mind.

Imagine presenting to a class where one classmate’s family uses Ayurvedic remedies, another’s uses traditional Mexican herbal teas, and another’s relies on a hospital for a long illness. Everyone in the room has reasons for their choices. A respectful presentation names each tradition in its own terms, such as "Ayurveda teaches…", and then reports the evidence plainly.

Keep the audience in mind. Use a clear question on your first slide, a few key findings, and one simple chart or table. Define any hard word. Put a citation for every fact: who said it, what the source is called, and the year. If you quote someone, use their exact words and mark them; otherwise paraphrase, which means restating an idea in your own words while still naming the source.

End with care. Remind listeners that your project is not medical advice. Anyone thinking about a treatment should talk with a doctor, nurse or pharmacist, and should tell them about any herbs or supplements. Then invite questions, and listen. A good health presentation leaves people better informed, and still feeling respected.