Published today as a research letter in The Lancet, their study compared the newer monovalent COVID vaccine, which specifically targets the XBB variant of Omicron (as recommended by the World Health Organisation), with older bivalent vaccines containing a mix of an Omicron variant and the original strain of COVID-19, which the UK deployed in Autumn 2023 before turning to monovalent vaccines¹.

The researchers found that both vaccines generated neutralising antibodies against the most recent strain of Omicron, BA.2.86. However, the new monovalent vaccine generated higher levels of antibodies against a range of other Omicron variants.

The team collected blood and nasal mucosal samples both before and after a fifth dose vaccination from 71 participants of the Legacy study, a research collaboration between the Crick and the NIHR University College London Hospitals Biomedical Research Centre. They compared the antibody levels before and after vaccination.

All 36 participants who received the bivalent vaccine and 17 who received the monovalent vaccine had boosted levels of antibodies against all variants tested, including the newest strain BA.2.86, which caused a wave of infection this winter. But those with the newer monovalent vaccine had 3.5x higher levels of antibodies against the XBB and BQ.1.1 strains after their booster vaccination.

Since the Omicron virus is highly transmissible and the virus replicates in the nose and throat, the researchers tested the levels of antibodies in the participants’ nasal cavity.

They found that the monovalent vaccine increased their ability to produce mucosal antibodies against most of the tested variants, whereas the bivalent vaccine didn’t provide a significant boost.

Neither vaccine increased neutralising antibody levels in the nasal cavity against the newest variant, BA.2.86, suggesting that current vaccines may be less likely to stop transmission or prevent asymptomatic or mild illness, while still protecting against severe disease.

This highlights the importance of careful vaccine updates and continuing to complement a vaccination programme with the development of antibody drugs that work against all variants, as some more vulnerable people don’t respond well to vaccines.

Emma Wall, Senior Clinical Research Fellow at the Crick and Consultant in Infectious Diseases at UCLH, said: “The UK’s strategy to deploy stocks of older vaccines paid off last year, as both vaccines provided equal protection against the newest strain. However, ongoing monitoring is needed, as the virus is continuing to evolve, so vaccine-induced antibodies might not work so well in the future. In the long run, vaccines that are effective against all new variants and can block COVID-19 being transmitted from person to person are needed.”

David LV Bauer, Group Leader of the RNA Virus Replication Laboratory at the Crick, said: “The situation this winter could have been different if the newly emerged BA.2.86 and JN.1 variants were substantially distinct from older Omicron variants, but fortunately this wasn’t the case.

“Most new variants arise quicker than most clinical trials can produce data. But laboratory analysis can provide a detailed picture very quickly. Continued surveillance will help us stay on top of viral evolution.”

That is what Ben-Gurion University of the Negev physicist Prof. Hezi Yizhaq and Prof. Itzhak Katra and their colleagues from Denmark, Germany, Italy, China, and the US contend in a cover article published in Nature Geoscience.

Sand ripples photographed on Mars by NASA’s Curiosity rover in 2015 showed two distinct patterns — large ripples (meter scale) and a shorter “impact” ripples pattern (decimeter scale). The prevailing theory proposed since then argues that the smaller scale ripples are produced by the impact mechanism of the particles transported by the wind like normal ripples on Earth and the larger ripples form due to hydrodynamic instability like subaqueous ripples. Furthermore, it was believed that the physical conditions that produced them on Mars could not produce them on Earth.

However, Prof. Yizhaq and Prof. Katra have proven experimentally using Ben-Gurion University’s wind tunnel and Aarhus University’s Mars tunnel that such a phenomenon could exist on Earth — we just haven’t noticed it yet because we didn’t know we should be looking for it.

Imitating Martian sand was not easy because it’s finer than sand here on Earth, explains Prof. Yizhaq, but the breakthrough occurred when they decided to try tiny glass balls to represent fine grains of sand.

Furthermore, the international research team has proposed a unified theoretical framework that would explain sand ripples on Mars and on Earth. At its most basic level, sand ripples on Mars caused by wind look like sand ripples on Earth caused by water.

“There is much more research, both fieldwork and experimentally, needed to prove our theory, but it is amazing to propose something so radically new in a field I have been studying for over 20 years. It is exciting to go out and try to find on Earth what can clearly be seen on Mars,” says Prof. Yizhaq.

Prof. Yizhaq is a member of the Department of Solar Energy and Environmental Physics. Prof. Itzhak Katra is a member of the Department of Environmental, Geoinformatics and Urban Planning Sciences.

The research was supported by the Israel Science Foundation (Grant no. 1270/20), the German-Israel Foundation for Scientific Research and Development (GIF) (Grant no. 155-301.10/2018), the National Natural Science Foundation of China, Texas A&M Engineering Experiment Station, Europlanet grant no. 871149, and the Horizon 2020 Research and Innovation Program.

“Our earlier work introduced the idea of a fourth traffic signal called a ‘white phase,’ which taps into the computing power of autonomous vehicles (AVs) in order to expedite traffic at intersections — but we had not yet incorporated what this concept would mean for pedestrians,” says Ali Hajbabaie, corresponding author of the paper and an associate professor of civil, construction and environmental engineering at North Carolina State University. “We’ve now expanded our computational modeling to account for foot traffic, and the results are extremely promising for both pedestrians and vehicles.”

The white phase concept makes use of AVs’ ability to communicate wirelessly with both each other and the computers that control the traffic signals. When enough AVs are approaching the intersection, this would activate a new traffic light — the white light. While red lights mean stop, and green lights mean go, white lights tell human drivers to simply follow the car in front of them. In short, the white light is a signal that AVs are coordinating their movement to facilitate traffic through the intersection more efficiently.

“Our previous research found that the more AVs there are on the road, the more efficiently the traffic moves,” Hajbabaie says. “To be clear, this improves travel time, fuel efficiency and safety for all of the cars on the road — not just AVs.”

To account for pedestrian traffic, the researchers incorporated a suite of new parameters into the optimization model that assessed the impact foot traffic would have on all traffic through an intersection.

“We found that, when pedestrians are added into the mix, the white phase concept still improves traffic efficiency for everyone,” Hajbabaie says. “And, again, the higher the percentage of traffic that is made up of AVs, the more efficiently traffic moves through intersections.

“If at some point in the future we see almost universal adoption of AVs, our models suggest that delays at intersections would decrease by more than 25%. More realistically, we will eventually see a lower percentage of wirelessly connected AVs on the road, but there would still be meaningful improvements in traffic time.”

The researchers know that governments will not be adopting these new traffic technologies in the immediate future, but are already taking steps to ensure that future pilot projects will be safe and effective.

“We are currently setting up a physical testbed that will allow us to experiment with this concept in the physical world — not just in a computer model,” Hajbabaie says. “However, the vehicles we are using in the testbed are small enough to hold in your hands. This will help us identify challenges in implementation without the expense — and safety risk — involved with using full-scale vehicles. In the meantime, we are open to working with industry and research partners to explore ways to move forward with these technologies.”