Ending pandemics is a social decision, not scientific. Governments and organizations rely on social, cultural and political considerations to decide when to officially declare the end of a pandemic. Ideally, leaders try to minimize the social, economic and public health burden of removing emergency restrictions while maximizing potential benefits.

Vaccine policy is a particularly complicated part of pandemic decision-making, involving a variety of other complex and often contradicting interests and considerations. Although COVID-19 vaccines have saved millions of lives in the U.S., vaccine policymaking throughout the pandemic was often reactive and politicized.

A late November 2022 Kaiser Family Foundation poll found that one-third of U.S. parents believed they should be able to decide not to vaccinate their children at all. The World Health Organization and the United Nations Children’s Fund reported that between 2019 and 2021, global childhood vaccination experienced its largest drop in the past 30 years.

The Biden administration formally removed federal COVID-19 vaccination requirements for federal employees and international travelers in May 2023. Soon after, the U.S. government officially ended the COVID-19 public health emergency. But COVID-19’s burden on health systems continues globally.

I am a public health ethicist who has spent most of my academic career thinking about the ethics of vaccine policies. For as long as they’ve been around, vaccines have been a classic case study in public health and bioethics. Vaccines highlight the tensions between personal autonomy and public good, and they show how the decision of an individual can have populationwide consequences.

COVID-19 is here to stay. Reflecting on the ethical considerations surrounding the rise – and unfolding fall – of COVID-19 vaccine mandates can help society better prepare for future disease outbreaks and pandemics.

Ethics of vaccine mandates

Vaccine mandates are the most restrictive form of vaccine policy in terms of personal autonomy. Vaccine policies can be conceptualized as a spectrum, ranging from least restrictive, such as passive recommendations like informational advertisements, to most restrictive, such as a vaccine mandate that fines those who refuse to comply.

Each sort of vaccine policy also has different forms. Some recommendations offer incentives, perhaps in the form of a monetary benefit, while others are only a verbal recommendation. Some vaccine mandates are mandatory in name only, with no practical consequences, while others may trigger termination of employment upon noncompliance.

COVID-19 vaccine mandates took many forms throughout the pandemic, including but not limited to employer mandates, school mandates and vaccination certificates – often referred to as vaccine passports or immunity passports – required for travel and participation in public life.

Because of ethical considerations, vaccine mandates are typically not the first option policymakers use to maximize vaccine uptake. Vaccine mandates are paternalistic by nature because they limit freedom of choice and bodily autonomy. Additionally, because some people may see vaccine mandates as invasive, they could potentially create challenges in maintaining and garnering trust in public health. This is why mandates are usually the last resort.

However, vaccine mandates can be justified from a public health perspective on multiple grounds. They’re a powerful and effective public health intervention.

Mandates can provide lasting protection against infectious diseases in various communities, including schools and health care settings. They can provide a public good by ensuring widespread vaccination to reduce the chance of outbreaks and disease transmission overall. Subsequently, an increase in community vaccine uptake due to mandates can protect immunocompromised and vulnerable people who are at higher risk of infection.

COVID-19 vaccine mandates

Early in the pandemic, arguments in favor of mandating COVID-19 vaccines for adults rested primarily on evidence that COVID-19 vaccination prevented disease transmission. In 2020 and 2021, COVID-19 vaccines seemed to have a strong effect on reducing transmission, therefore justifying vaccine mandates.

COVID-19 also posed a disproportionate threat to vulnerable people, including the immunocompromised, older adults, people with chronic conditions and poorer communities. As a result, these groups would have significantly benefited from a reduction in COVID-19 outbreaks and hospitalization.

Many researchers found personal liberty and religious objections insufficient to prevent mandating COVID-19 vaccines. Additionally, decision-makers in favor of mandates appealed to the COVID-19 vaccine’s ability to reduce disease severity and therefore hospitalization rates, alleviating the pressure on overwhelmed health care facilities.

However, the emergence of even more transmissible variants of the virus dramatically changed the decision-making landscape surrounding COVID-19 vaccine mandates.

The public health intention (and ethicality) of original COVID-19 vaccine mandates became less relevant as the scientific community understood that achieving herd immunity against COVID-19 was probably impossible because of uneven vaccine uptake, and breakthrough infections among the vaccinated became more common. Many countries like England and various states in the U.S. started to roll back COVID-19 vaccine mandates.

With the rollback and removal of vaccine mandates, decision-makers are still left with important policy questions: Should vaccine mandates be dismissed, or is there still sufficient ethical and scientific justification to keep them in place?

Vaccines are lifesaving medicines that can help everyone eligible to receive them. But vaccine mandates are context-dependent tools that require considering the time, place and population they are deployed in.

Though COVID-19 vaccine mandates are less of a publicly pressing issue today, many other vaccine mandates, particularly in schools, are currently being challenged. I believe this is a reflection of decreased trust in public health authorities, institutions and researchers – resulting in part from tumultuous decision-making during the COVID-19 pandemic.

Engaging in transparent and honest conversations surrounding vaccine mandates and other health policies can help rebuild and foster trust in public health institutions and interventions.

Rachel Gur-Arie, Assistant Professor of Nursing and Health Innovation, Arizona State University

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

Hundreds of millions of tons of single-use plastic ends up in landfills every year, and even the small percentage of plastic that gets recycled can’t last forever. But our group of materials scientists has developed a new method for creating and deconstructing polymers that could lead to more easily recycled plastics – ones that don’t require you to carefully sort out all your recycling on trash day.

In the century since their conception, people have come to understand the enormous impacts – beneficial as well as detrimental – plastics have on human lives and the environment. As a group of polymer scientists dedicated to inventing sustainable solutions for real-world problems, we set out to tackle this issue by rethinking the way polymers are designed and making plastics with recyclability built right in.

Why use plastics, anyway?

Everyday items including milk jugs, grocery bags, takeout containers and even ropes are made from a class of polymers called polyolefins. Polyolefins make up around half of the plastics produced and disposed of every year.

These polymers are used in plastics commonly labeled as HDPE, LLDPE or PP, or by their recycling codes #2, #4 and #5, respectively. These plastics are incredibly durable because the chemical bonds that make them up are extremely stable. But in a world set up for single-use consumption, this is no longer a design feature but rather a design flaw.

Imagine if half of the plastics used today were recyclable by twice as many processes as they are now. While that wouldn’t get the recycling rate to 100%, a jump from single digits – currently around 9% – to double digits would make a big dent in the plastics produced, the plastics accumulated in the environment and their capacity for recycling and reuse.

Recycling methods we already have

Even the plastics that make it to a recycling facility can’t be reused in exactly the same way they were used before – the recycling process degrades the material, so it loses utility and value. Instead of making a plastic cup that is downgraded each time it gets recycled, manufacturers could potentially make plastics once, collect them and reuse them on and on.

Conventional recycling requires careful sorting of all the collected materials, which can be hard with so many different plastics. Here in the U.S., collection happens mainly through single stream recycling – everything from metal cans, glass bottles, cardboard boxes and plastic cups end up in the same bin. Separating paper from metal doesn’t require complex technology, but sorting a polypropylene container from a polyethylene milk jug is hard to do without the occasional mistake.

When two different plastics are mixed together during recycling, their useful properties are hugely reduced – to the point of making them useless.

But say you can recycle one of these plastics by a different method, so it doesn’t end up contaminating the recycling stream. When we mixed samples of polypropylene with a polymer we made, we were still able to depolymerize – or break down the material – and regain our building blocks without chemically affecting the polypropylene. This indicated that a contaminated waste stream could still recover its value, and the material in it could go on to be recycled, either mechanically or chemically.

Plastics we need − but more recyclable

In a study published in October 2023, our team developed a series of polymers with only two simple building blocks – one soft polymer and one hard polymer – that mimicked polyolefins but could also be chemically recycled.

Connecting two different polymers together multiple times until they form a single, long molecule creates what’s called a multiblock polymer. Just by adjusting how much of each polymer type goes into the multiblock polymer, our team created a wide range of materials with properties that spanned across polyolefin types. But creating these multiblock polymers is easier said than done.

To link these hard and soft polymers, we adapted a technique that had previously been used only on very small molecules. This method is improved relative to traditional methods of making polymers in a step-by-step fashion, developed in the 1920s, where the reactive groups on the end of the molecules need to be exactly matched.

In our method, the reactive groups are now the same as each other, meaning we didn’t have to worry about pairing the ends of each building block to make polymers that can compete with the polyolefins we already use. Using the same strategy, applied in reverse by adding hydrogen, we could disconnect the polymers back into their building blocks and easily separate them to use again.

With an almost twofold increase in annual plastic use projected through 2050, the complexity and quantity of plastic recycling will only increase. It’s an important consideration when designing new materials and products.

Using just two building blocks to make plastics that have a huge variety of properties can go a long way toward reducing and streamlining the number of different plastics used to make the products we need. Instead of needing one plastic to make something pliable, another for something stiff, and a third, fourth and fifth for properties in between, we could control the behavior of plastics by just changing how much of each building block is there.

Although we’re still in the process of answering some big questions about these polymers, we believe this work is a step in the right direction toward more sustainable plastics.

We were able to create materials that mimic the properties of plastics the world relies on, and our sights are now set on creating plastic compositions that you couldn’t with existing methods.

Katherine Harry, PhD Student in Chemistry, Colorado State University and Emma Rettner, PhD Candidate in Materials Science and Engineering, Colorado State University

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