We know vaccines have been a miracle for public health. Now, new research led by the World Health Organization has found vaccines have saved an estimated 154 million lives in the past 50 years from 14 different diseases. Most of these have been children under five, and around two-thirds children under one year old.

In 1974 the World Health Assembly launched the Expanded Programme on Immunization with the goal to vaccinate all children against diphtheria, tetanus, pertussis (whooping cough), measles, polio, tuberculosis and smallpox by 1990. The program was subsequently expanded to include several other diseases.

The modelling, marking 50 years since this program was established, shows a child aged under ten has about a 40% greater chance of living until their next birthday, compared to if we didn’t have vaccines. And these positive effects can be seen well into adult life. A 50-year-old has a 16% greater chance of celebrating their next birthday thanks to vaccines.

What the study did

The researchers developed mathematical and statistical models which took in vaccine coverage data and population numbers from 194 countries for the years 1974–2024. Not all diseases were included (for example smallpox, which was eradicated in 1980, was left out).

The analysis includes vaccines for 14 diseases, with 11 of these included in the Expanded Programme on Immunization. For some countries, additional vaccines such as Japanese encephalitis, meningitis A and yellow fever were included, as these diseases contribute to major disease burden in certain settings.

The models were used to simulate how diseases would have spread from 1974 to now, as vaccines were introduced, for each country and age group, incorporating data on increasing vaccine coverage over time.

Children are the greatest beneficiaries of vaccines

Since 1974, the rates of deaths in children before their first birthday has more than halved. The researchers calculated almost 40% of this reduction is due to vaccines.

The effects have been greatest for children born in the 1980s because of the intensive efforts made globally to reduce the burden of diseases like measles, polio and whooping cough.

Some 60% of the 154 million lives saved would have been lives lost to measles. This is likely due to its ability to spread rapidly. One person with measles can spread the infection to 12–18 people.

The study also found some variation across different parts of the world. For example, vaccination programs have had a much greater impact on the probability of children living longer across low- and middle-income countries and settings with weaker health systems such as the eastern Mediterranean and African regions. These results highlight the important role vaccines play in promoting health equity.

Vaccine success is not assured

Low or declining vaccine coverage can lead to epidemics which can devastate communities and overwhelm health systems.

Notably, the COVID pandemic saw an overall decline in measles vaccine coverage, with 86% of children having received their first dose in 2019 to 83% in 2022. This is concerning because very high levels of vaccination coverage (more than 95%) are required to achieve herd immunity against measles.

In Australia, the coverage for childhood vaccines, including measles, mumps and rubella, has declined compared to before the pandemic.

This study is a reminder of why we need to continue to vaccinate – not just against measles, but against all diseases we have safe and effective vaccines for.

The results of this research don’t tell us the full story about the impact of vaccines. For example, the authors didn’t include data for some vaccines such as COVID and HPV (human papillomavirus). Also, like with all modelling studies, there are some uncertainties, as data was not available for all time periods and countries.

Nonetheless, the results show the success of global vaccination programs over time. If we want to continue to see lives saved, we need to keep investing in vaccination locally, regionally and globally.

Meru Sheel, Associate Professor and Epidemiologist, Infectious Diseases, Immunisation and Emergencies Group, Sydney School of Public Health, University of Sydney and Alexandra Hogan, Mathematical epidemiologist, UNSW Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Sweating is our body’s way of cooling down, a bit like an internal air conditioner.

When our core temperature rises (because it’s hot outside, or you’re exercising), sweat glands all over our skin release a watery fluid. As that fluid evaporates, it takes heat with it, keeping us from overheating.

But sweating can vary from person to person. Some people might just get a little dewy under the arms, others feel like they could fill a swimming pool (maybe not that dramatic, but you get the idea).

So what’s a normal amount of sweat? And what’s too much?

Why do some people sweat more than others?

How much you sweat depends on a number of factors including:

• your age (young kids generally sweat less than adults)
• your sex (men tend to sweat more than women)
• how active you are.

The average person sweats at the rate of 300 millilitres per hour (at 30°C and about 40% humidity). But as you can’t go around measuring the volume of your own sweat (or weighing it), doctors use another measure to gauge the impact of sweating.

They ask whether sweating interferes with your daily life. Maybe you stop wearing certain clothes because of the sweat stains, or feel embarrassed so don’t go to social events or work.

If so, this is a medical condition called hyperhidrosis, which affects millions of people worldwide.

People with this condition most commonly report problematic armpit sweating, as you’d expect. But sweaty hands, feet, scalp and groin can also be an issue.

Hyperhidrosis can be a symptom of another medical condition, such as an overactive thyroid, fever or menopause.

But hyperhidrosis can have no obvious cause, and the reasons behind this so-called primary hyperhidrosis are a bit of a mystery. People have normal numbers of sweat glands but researchers think they simply over-produce sweat after triggers such as stress, heat, exercise, tobacco, alcohol and hot spices. There may also be a genetic link.

OK, I sweat a lot. What can I do?

1. Antiperspirants

Antiperspirants, particularly ones with aluminium, are your first line of defence and are formulated to reduce sweating. Deodorants only stop body odour.

Aluminum chloride hexahydrate, aluminium chloride or the weaker aluminum zirconium tetrachlorohydrex glycinate react with proteins in the sweat glands, forming a plug. This plug temporarily blocks the sweat ducts, reducing the amount of sweat reaching the skin’s surface.

These products can contain up to 25% aluminium. The higher the percentage the better these products work, but the more they irritate the skin.

2. Beat the heat

This might seem obvious, but staying cool can make a big difference. That’s because you have less heat to lose, so the body makes less sweat.

Avoid super-hot, long showers (you will have more heat to loose), wear loose-fitting clothes made from breathable fabrics such as cotton (this allows any sweat you do produce to evaporate more readily), and carry a little hand fan to help your sweat evaporate.

When exercising try ice bandanas (ice wrapped in a scarf or cloth, then applied to the body) or wet towels. You can wear these around the neck, head, or wrists to reduce your body temperature.

Try also to modify the time or place you exercise; try to find cool shade or air-conditioned areas when possible.

If you have tried these first two steps and your sweating is still affecting your life, talk to your doctor. They can help you figure out the best way to manage it.

3. Medication

Some medications can help regulate your sweating. Unfortunately some can also give you side effects such as a dry mouth, blurred vision, stomach pain or constipation. So talk to your doctor about what’s best for you.

Your GP may also refer you to a dermatologist – a doctor like myself who specialises in skin conditions – who might recommend different treatments, including some of the following.

4. Botulinum toxin injections

Botulinum toxin injections are not just used for cosmetic reasons. They have many applications in medicine, including blocking the nerves that control the sweat glands. They do this for many months.

A dermatologist usually gives the injections. But they’re only subsidised by Medicare in Australia for the armpits and if you have primary hyperhidrosis that hasn’t been controlled by the strongest antiperspirants. These injections are given up to three times a year. It is not subsidised for other conditions, such as an overactive thyroid or for other areas such as the face or hands.

If you don’t qualify, you can have these injections privately, but it will cost you hundreds of dollars per treatment, which can last up to six months.

5. Iontophoresis

This involves using a device that passes a weak electrical current through water to the skin to reducing sweating in the hands, feet or armpits. Scientists aren’t sure exactly how it works.

But this is the only way to control sweating of the hands and feet that does not require drugs, surgery or botulinum toxin injections.

This treatment is not subsidised by Medicare and not all dermatologists provide it. However, you can buy and use your own device, which tends to be cheaper than accessing it privately. You can ask your dermatologist if this is the right option for you.

6. Surgery

There is a procedure to cut certain nerves to the hands that stop them sweating. This is highly effective but can cause sweating to occur elsewhere.

There are also other surgical options, which you can discuss with your doctor.

7. Microwave therapy

This is a newer treatment that zaps your sweat glands to destroy them so they can’t work any more. It’s not super common yet, and it is quite painful. It’s available privately in a few centres.

Michael Freeman, Associate Professor of Dermatology, Bond University

This article is republished from The Conversation under a Creative Commons license. Read the original article.