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Armed police officers stand guard as a male health worker carrying a cool box administers a polio vaccine to baby in Pakistan

Health workers administer polio vaccine to children in Islamabad in January as an armed police officer stands nearby for protection. Vaccinators have previously been attacked in Pakistan, where rumours persist about immunizations being harmful.Credit: Sohail Shahzad/EPA-EFE/Shutterstock

World health stumbles under COVID burden

Campaigns to quash tuberculosis (TB), measles and polio have all been set back by the need to divert medical resources to COVID-19. Half a million more people than usual might have died of TB last year because of a drop in the number of people who received life-saving treatment, according to World Health Organization estimates. The data suggest that the knock-on effects of the pandemic could be larger than those caused by COVID-19 itself — and that they will linger long after the pandemic has ended.

Nature | 12 min read

Measles vaccinations on hold. Map showing world vaccination coverage and countries which postponed campaigns.

Source: CDC/WHO

Allergy-free pigs could provide transplants

Genetically engineered pigs could soon provide a safe source of meat for people with a tick-bite-induced allergic reaction to a sugar molecule found on the surface of porcine cells. The US Food and Drug Administration authorized the production of the pigs, which lack the gene needed to produce galactose-α-1,3-galactose, late last year. Researchers say the approval is an important first step towards the goal of using organs from engineered pigs for transplants into humans. But many technical and regulatory hurdles remain. When it comes to gene-edited animals “the system is set up as if you’re dealing with kryptonite”, says animal geneticist Alison Van Eenennaam.

Nature Biotechnology | 9 min read

Video: How to fly a helicopter on Mars

On Monday, NASA’s Ingenuity drone made the first powered flight on another world. The robot rotorcraft — part of NASA’s Perseverance mission — lifted off from the surface of Mars for almost 40 seconds. Watch the historic moment and explore what it means for the future of space exploration.

Nature | 6 min video

COVID-19 coronavirus update

India’s COVID surge puzzles scientists

The pandemic is sweeping through India at a pace that has staggered scientists. Daily case numbers have exploded since March: the government reported 273,810 new infections nationally on 18 April. High numbers in India have helped to drive global cases to a daily high of 854,855 in the past week, almost breaking a record set in January. Just months earlier, antibody data had suggested that many people in cities such as Delhi and Chennai had already been infected, leading some researchers to conclude that the worst of the pandemic was over in the country. Researchers in India are now trying to pinpoint what is behind the unprecedented surge, which could be due to an unfortunate confluence of factors — including the emergence of infectious variants, a rise in unrestricted social interactions and low vaccine coverage.

Nature | 6 min read

How Africa will make its own vaccines

For decades, Africa has imported 99% of its vaccines. Now, the continent’s leaders want to bring manufacturing home. Last week, heads of state attending a meeting co-organized by Africa Centres for Disease Control and Prevention and the African Union pledged to increase the share of vaccines manufactured in Africa from 1% to 60% by 2040. This includes building factories and bolstering capacity in research and development. Key to the challenging plan’s success will be finding financing, harmonizing regulation — perhaps by establishing an African Medicines Agency — and learning from the successes of other low- and middle-income regions.

Nature | 6 min read

Read the accompanying editorial: Africa’s vaccines revolution must have research at its core (Nature | 7 min read)

Features & opinion

Close up of a brain tumour being dissected in a petri dish lit from beneath

Tiny pieces of a patient’s glioblastoma brain tumour can be used to grow organoid models for studying the role of cancer stem cells in disease.Credit: Jessica Kourkounis/The Washington Post/Getty

Developmental-biology tools take on cancer

Since the 1990s, researchers have suspected that stem cells in cancers hold the key to disease recurrence, cancer spread (or metastasis) and resistance to therapies. But cancer stem cells seem to defy characterization. They bear no defining molecular markers; they might not exist in every tumour; and, perhaps most frustratingly of all, correlate little with disease aggressiveness or treatment outcomes. Now, researchers are exploiting methods from developmental biology to understand whether — and how — cancer stem cells spur disease.

Nature | 11 min read

Blanket fossil-fuel bans entrench poverty

A move by the United States and several European countries to stop supporting fossil-fuel projects abroad will entrench poverty in regions such as sub-Saharan Africa, but do little to reduce the world’s carbon emissions, argues economist Vijaya Ramachandran. Africa accounts for around 17% of the world’s people but less than 4% of annual global carbon emissions: in 4 days, the average person in the United States consumes the electricity that the average Ethiopian consumes in a year. And most of the legacy emissions causing global warming came from rich countries. Instead, rich countries should help African governments to pursue a broad portfolio of energy sources for rapid, sustainable development.

Nature | 5 min read

The seductive mystery of axions

A hypothetical fundamental particle called the axion could provide a missing piece of the standard model of particle physics and offer an answer to the mysterious nature of dark matter. Physicist Chanda Prescod-Weinstein explains the theory behind the axion, how experimental physicists are searching for it and how its delights drew her to become an expert in a field she once considered boring.

American Scientist | 18 min read

Quote of the day

“When we fill urban landscapes with introduced plants, we are severing crucial, dependent relationships between native plants and wildlife that have evolved over millennia.”

Native plants — and embracing ‘messy’ gardens — are key to creating healthy urban ecosystems, argue conservation scientist Sheila Colla and environmental writer Lorraine Johnson. (Toronto Star | 4 min read)