MALARIA is the largest cause of death in young African children, and the disease claims over 6,00,000 lives globally each year. Now, results are out of the phase 3 trial data of the R21/Matrix-M™ malaria vaccine developed by Oxford University and Serum Institute of India. The double-blinded, randomised trials, conducted among 4,800 children in the 5–36 months age group in Burkina Faso, Kenya, Mali, and Tanzania, found that over three-fourths of them were protected from the disease during the first year of follow-up across all sites.

Efficacy over this period was broadly similar across all sites, both seasonal and standard (where malaria occurs year round), and in different transmission settings. The 12-month vaccine efficacy was 75 per cent at the seasonal sites and 68 per cent at the standard sites until the first clinical malaria episode was seen. Similarly, vaccine efficacy against episodes was 75 per cent at the seasonal sites and 67 per cent at standard sites.

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The vaccine was administered in three doses, four weeks apart, with a booster administered 12 months after the third dose. The booster maintained good efficacy over the following six to 12 months, according to the trial results that were published in The Lancet in February, although it was seen to reduce modestly afterwards. The vaccine also reduced infection rates in children measured at 12 and 18 months after vaccination, suggesting a potentially beneficial effect in reducing malaria transmission.

No serious adverse event was found that could be linked to immunisation. No other vaccine has reported over 55 per cent efficacy in the same age group.

The vaccine R21 also uses an adjuvant, or an immune-boosting component, called Matrix-M developed by Novavax. The vaccine obtained the WHO’s approval last year and has got regulatory approvals and licensure in several African countries.

This is the second malaria vaccine to have achieved and completed WHO pre-qualification, the other being RTS,S/AS01 (GlaxoSmithKline), which the WHO has recommended for use in children aged 5–17 months in moderate-to-high transmission settings. It had successful trial results last year in Cameroon. The R21 was designed in 2011 as a potential improvement on RTS,S/AS01.

Russia, India sign new protocol on Kudankulam reactors

ALEXEY LIKHACHEV, Director General of Russia’s Rosatom, on his recent visit to India signed a new protocol to the Intergovernmental Agreement (IGA) on the Kudankulam Nuclear Power Station (KKNPS). It was finalised on February 8 following negotiations between Likhachev and Ajit Kumar Mohanty, Chairman, Atomic Energy Commission, and Secretary, Department of Atomic Energy (DAE).

The protocol governs the amendment now made to the IGA of 2008. The IGA is an umbrella agreement for VVER-1000 nuclear reactor units 1–6 in phases. In Phase I, units 1 and 2 were completed and became operational in 2014 and 2017 respectively. Phase II comprising units 3 and 4 and Phase III comprising units 5 and 6 are under construction. The general framework agreement between Rosatom and Nuclear Power Corporation of India Ltd on the construction of units 3 and 4 was signed in 2014, and work began on them in 2017. A similar agreement was signed in 2017 for units 5 and 6, and work on them began in 2021. The KKNPS (with units 1–6) is expected to be operating at full capacity by 2027.

The expanded cooperation envisages construction of 12 units, and the recent amendment, in all likelihood, governs these additional units. In particular, for units 7 and 8, VVER-1200 reactors (an evolution from VVER-1000 based on AES-2006 design) have been proposed in Phase IV. The general contractor for the project is Rosatom subsidiary Atomstroyexport.

Meanwhile, it was reported that the pressure vessel (weighing 317 tonnes) was successfully installed on January 24 in unit 4. The same “open top” method first used at Kudankulam 3 was used again. It involves installing the component while the reactor dome is still open and can significantly cut the time taken to carry out the installation. The procedure involves moving the vessel to a vertical position, then lifting it by crane to a height of 50 m, and then lowering it into the reactor shaft of the reactor building.

1.5°C warming limit passed long ago

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THE most important measure of global warming has come from sea-surface temperature (SST) records. However, these date back only about 180 years. Now, a team of scientists from the University of Western Australia (UWA), Indiana State University, and the University of Puerto Rico-Mayaguez, led by Malcolm McCulloch of the UWA, accessed much earlier temperature records preserved in skeletons of long-lived sea sponges from the Eastern Caribbean. According to this first-of-its-kind study, global temperatures may have already exceeded 1.5°C warming and may pass 2°C later this decade. The study was published in a recent issue of Nature Climate Change.

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The findings suggest climate change has progressed a good deal beyond what the climate scientist community, the Intergovernmental Panel on Climate Change in particular, has so far believed. The Paris Accords of 2015 under the UN Framework Convention on Climate Change had set a guard rail of 1.5°C, which nations agreed not to exceed.

“Our research… suggests that opportunity has passed. Earth may in fact have already reached at least 1.7°C warming since pre-industrial times—a deeply troubling discovery,” McCulloch wrote in the website The Conversation.

 The team analysed the strontium to calcium ratio in the 300-year-old calcium carbonate skeletons of a sponge species, Ceratoporella nicholsoni (in picture). This ratio changes only with seawater temperature, which makes it a proxy thermometer.
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The team analysed the strontium to calcium ratio in the 300-year-old calcium carbonate skeletons of a sponge species, Ceratoporella nicholsoni. This ratio changes only with seawater temperature, which makes it a proxy thermometer. In fact, McCulloch has termed the technique “sclerosponge thermometry”.

The only place where this species grows is off the coasts of Puerto Rico. Samples were collected at a depth of 33–91 m. “SST can be highly variable on top,” McCulloch told Nature. “But this mixed layer represents the whole system down to a couple hundred metres, and it’s in equilibrium with the temperatures in the atmosphere.”