THE following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.

Vaccines designed for virus variants show promise in mice

Moderna Inc vaccines designed to protect against the worrisome coronavirus variants identified in South Africa and Brazil have yielded promising results when tested in mice, according to new data. The company tested two new approaches against the variants - a single-dose "booster" for mice vaccinated months earlier with both doses of the original Moderna vaccine, and a separate new two-shot version combining the original vaccine with the booster in mice that had never been vaccinated. In both scenarios, according to a paper posted on Tuesday on bioRxiv ahead of peer review, the treated animals had "significant" levels of antibodies against the original strain of the virus and comparably high levels of antibodies capable of neutralizing both the B.1.351 South African variant and the P.1 Brazil variant. Tests of the two new vaccines in humans are already underway. 

Hospital patients with UK variant do not face higher risks

A highly contagious variant of the coronavirus first identified in Britain, known as B.1.1.7, does not cause more severe disease in hospitalized patients, according to a study published on Monday in The Lancet Infectious Diseases. B.1.1.7 is now the most common variant of the coronavirus in the United States, according to the U.S. Centers for Disease Control and Prevention, and accounts for the vast majority of new cases in the UK. The new study compared 198 patients with B.1.1.7 infections and 143 with COVID-19 caused by other variants, all of whom were admitted to British hospitals in November and December. Patients infected with the UK variant had higher viral loads, which aligns with previous findings that B.1.1.7 is more transmissible. But the researchers saw no difference in the risks of critical illness, death, or other clinical outcomes in patients with B.1.1.7 and other variants. "Our data ... provide initial reassurance that severity in hospitalized patients with B.1.1.7 is not markedly different from severity in those without," the researchers said. 

Empty middle airplane seats would cut coronavirus exposure

Keeping middle airplane seats vacant could cut the risk of exposure to the coronavirus by 23% to 57% compared with a full flight, according to a simulation study on physical distancing onboard released on Wednesday by the U.S. Centers for Disease Control and Prevention in its Morbidity and Mortality Weekly Report. The researchers based their findings on laboratory modeling of exposure to the coronavirus on single-aisle and twin-aisle aircraft. "It is important to recognize that the current study addresses only exposure," not actual transmission resulting in infections, and it did not consider the impact of masking, the researchers said. U.S. airlines blocked middle seats early in the pandemic but have gradually opened them up, citing studies showing low transmission risk if everyone onboard wears a mask. The authors of the new study, however, say earlier research found "masking seems to not eliminate all airborne exposures to infectious droplets and aerosols and support the importance of multicomponent prevention strategies." Combining the effects of masking and distancing by means of empty middle seats would be more protective than either by itself, the researchers said.