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Local residents or Mariupol carry luggage as they walk past a high-rise building destroyed during Ukraine-Russia conflict

Ukrainians walk past a building in Mariupol that was destroyed during the Russian military’s invasion of their country.Credit: Alexander Ermochenko/Reuters

Risks of chemical weapons in Ukraine

Russia has denied any intention to use chemical weapons in its attack on Ukraine. But the Russian government has been linked over the past two decades with this type of attack — for example, in the case of a Novichok chemical attack in the United Kingdom in 2018 (the Kremlin denied involvement). The Wall Street Journal reported that attendees at Russia–Ukraine peace talks in March had been poisoned — although at least one Ukrainian government source has reportedly denied the story. Analysts explain why some fear that the Russian military will use chemical weapons — and how the world would know if it did.

Nature | 7 min read

Infected immune cells and severe COVID

Two studies have found that immune cells infected with SARS-CoV-2 can trigger a massive inflammatory response that could cause severe COVID-19.

• In a Nature paper, researchers looked at blood samples from people with COVID-19 and found evidence that the virus might activate inflammasomes, large molecules that trigger a cascade of inflammatory responses that ends in cell death.

• In a preprint study, which has not yet been peer-reviewed, researchers gave mice COVID drugs that blocked inflammasomes. The drugs “rescued the mice so they were not as sick”, says immunologist and co-author Esen Sefik.

More research is needed to work out how important infected immune cells are at driving severe COVID-19 compared with other possible mechanisms.

Nature | 4 min read

Reference: Nature paper & bioRxiv preprint

A lightning-fast ancient migration

Around 1,500 years ago, horse-riding warriors known as the Avars appeared in southeastern Europe seemingly out of nowhere and established an empire lasting more than 200 years. Now, DNA evidence suggests that they crossed a continent in the span of a decade or two. Human remains from Avar tombs in what is now Hungary closely match those from an individual buried just a few decades earlier in what is now eastern Mongolia — almost 7,000 kilometres away. “The DNA is so close it’s got to be within one generation, or less,” says geneticist and co-author Choongwon Jeong.

Science | 5 min read

Reference: Cell paper

Features & opinion

How Russia is rewriting energy geopolitics

Russia’s invasion of Ukraine has caused a short-term spike in fuel and food prices and could prompt a long-term shift towards sustainability. For now, one of the biggest questions facing world leaders is how to sever their energy dependence on Russia.

• The conflict could push Western economies, such as Germany, to push harder on renewables and incentivize unglamorous, but essential, investments in energy efficiency.

• If Europe turns to natural gas in a bid to reduce its reliance on oil, other regions — southeast Asia, in particular — could turn back towards coal.

• Decarbonization is likely to slow in Russia itself, which accounted for nearly 5% of global emissions in 2020.

Another key question is how rising energy prices and the potential loss of grain supplies from Ukraine and Russia could reinforce inflationary effects and drive up prices of food and other commodities. “One of the big casualties of the Russian invasion will be people who are already teetering on the edge in other places,” says economist Christopher Barrett. “It’s not just Ukrainians. It’s Yemenis, and Syrians, and Nigerians.”

Nature | 8 min read

Creating ‘a generation of researchers’

Leading Ugandan researcher Mahmoud Mamdani has stepped down after 12 years of heading the Makerere Institute for Social Research. During this time, he led a revamp of the institution’s mission “to focus on creating a generation of researchers — Ugandan and African”, he says. He reflects on his approach to learning and how to build a research institution when resources are scarce. “We do not teach our students to approach knowledge as some kind of a sacred gift that they should memorize,” says Mamdani. “They have to think of how they are going to contribute to this knowledge and not how they are going to consume it.”

University World News | 9 min read

Hepatitis B: closing in on a cure

Every year, more than 800,000 people worldwide die from liver disease caused by hepatitis B infection — a greater toll than from malaria. This is despite the fact that, unlike malaria, an effective childhood vaccine against the hepatitis B virus (HBV) has been available for more than 30 years. But there has been encouraging progress on several fronts. At centre stage is the quest for an outright cure for HBV — drugs that don’t just quiet the virus but eliminate it from the body permanently. Researchers predict that the next few years could bring a breakthrough akin to the cures for hepatitis C that have arrived in the past decade. To fulfil this goal, however, drug developers might well need to rethink the underlying biology of HBV infection.

Nature Outlook | Full collection

This editorially independent supplement is produced with the financial support of the Janssen Pharmaceutical Companies of Johnson & Johnson and of Vir Biotechnology.


“When [trainees] excel, it doesn’t just amplify the impact of my lab: it promotes the entire field.”

Biomedical engineer Kristi Anseth is one of five senior research leaders who offer their tips on building a legacy in science. (Nature | 10 min read)