20 public eye friday november 20, 2020 world news news coronavirus is airborne indoors why are we still scrubbing surfaces? people are removing masks for lunch or when they get back to their cubicle because they assume their cubicle is their private space mike ivesapoorva mandavilli hong kong — at hong kong’s deserted airport, cleaning crews constantly spray baggage trolleys, elevator buttons and check-in counters with antimicrobial solutions. in new york city, workers continually disinfect surfaces on buses and subways. in london, many pubs spent lots of money on intensive surface cleaning to reopen after lockdown - before closing again in november. all over the world, workers are soaping, wiping and fumigating surfaces with an urgent sense of purpose: to fi ght the coronavirus. but scientists increasingly say that there is little to no evidence that contaminated surfaces can spread the virus. in crowded indoor spaces like airports, they say, the virus that is exhaled by infected people and that lingers in the air is a much greater threat. hand washing with soap and water for 20 seconds - or sanitizer in the absence of soap - is still encouraged to stop the virus’s spread. but scrubbing surfaces does little to mitigate the virus threat indoors, experts say, and health officials are being urged to focus instead on improving ventilation and fi ltration of indoor air. “in my opinion, a lot of time, energy and money is being wasted on surface disinfection and, more importantly, diverting attention and resources away f r o m p r e v e n t i n g a i r b o r n e transmission,” said dr. kevin p. fennelly, a respiratory infection specialist with the united states national institutes of health. some experts suggest that hong kong, a crowded city of 7.5 million residents and a long history of infectious disease outbreaks, is a case study for the kind of operatic surface cleaning that gives ordinary people a false sense of security about the coronavirus. the hong kong airport authority has used a phone- booth-like “full-body disinfection channel” to spritz airport staff members in quarantine areas. the booth - which the airport says is the fi rst in the world and is being used in trials only on its staff - is part of an all-out eff ort to make the facility a “safe environment for all users.” s u c h d i s p l a y s c a n b e comforting to the public because they seem to show that local officials are taking the fight to covid-19. but shelly miller, an expert on aerosols at the university of colorado boulder, said that the booth made no practical sense from an infection- control standpoint. viruses are emitted through activities that spray respiratory droplets - talking, breathing, yelling, coughing, singing and s n e e z i n g. a n d d i s i n fe c t i n g sprays are o! en made from toxic chemicals that can signifi cantly affect indoor air quality and human health, dr. miller said. “i can’t understand why a n y o n e w o u l d t h i n k t h a t disinfecting a whole person would reduce the risk of transmitting virus,” she said. a ra n ge o f re s p i ra t o r y ailments, including the common cold and influenza, are caused by germs that can spread from c o n ta m i n a te d s u r fa c e s . so when the coronavirus outbreak emerged last winter in the chinese mainland, it seemed logical to astrazeneca covid-19 vaccine shows promise in elderly kate kelland, alistair smout london - astrazeneca and oxford university’s potential covid-19 vaccine produced a strong immune response in older adults, data published o n t h u rs d ay s h owe d , w i t h researchers expecting to release l a te - s ta ge t r i a l re s u l ts by christmas. the data, reported in part last month but published in full in the lancet medical journal on thursday, suggest that those aged over 70, who are at higher risk of serious illness and death from covid-19, could build robust immunity. “ t h e r o b u s t a n t i b o d y and t-cell responses seen in older people in our study are encouraging,” said maheshi ramasamy, a consultant and co- lead investigator at the oxford vaccine group. “we hope that this means our vaccine will help to protect some of the most vulnerable people in society, but further research will be needed before we can be sure.” late-stage, or phase iii, trials are ongoing to confi rm the fi ndings, researchers said, and to test whether the vaccine protects against infection with sars- cov-2 in a broad range of people, including people with underlying health conditions. results of those trials should defi nitely be known by christmas, the oxford vaccine group’s director, andrew pollard, said, adding it was too early to know whether and how well the vaccine works in preventing covid-19 disease. “we’re still waiting to get to the point where we can do the analysis to just work out how well the vaccine can protect people, and we’re getting ever closer to that,” he told journalists. “we are optimistic that we’ll be able to do that before christmas, and obviously we’ll share that with you as soon as we can at that point.” the oxford-astrazeneca covid-19 vaccine candidate, called azd1222 or chadox1 ncov-19, had been among the front-runners in global efforts to develop shots to protect against infection with the novel coronavirus, or sars-cov-2. but rival drugmakers pfizer inc pfe.n, biontech 22uay.f and moderna inc mrna.o have in the past 10 days edged ahead, releasing data from late-stage covid-19 vaccine trials that shows more than 90% effi cacy. “we’re not in a rush. we and it’s not a competition with the other developers,” oxford’s pollard said, adding that astrazeneca would release headline effi cacy data before it was published in an academic journal. oxford university has set a target of 53 infections to start the interim analysis of its late- stage trial results, though “lots of cases” in its trial arms in britain, south africa and brazil mean the exact number of infections reported could diff er. unlike the pfizer-biontech and moderna shots, both of which use new technology known as messenger rna (mrna), astrazeneca’s is a viral vector vaccine made from a weakened version of a common cold virus found in chimpanzees. the phase ii trial reported in the lancet involved a total of 560 healthy volunteers, with 160 aged 18-55, 160 aged 56-69, and 240 aged 70 or over. volunteers got two doses of the vaccine or a placebo, and no serious side eff ects related to the azd1222 vaccine were reported, the researchers said. astrazeneca azn.l has signed several supply and manufacturing d e a l s w i t h c o m pa n i e s a n d governments around the world. -reuters assume that these so-called fomites were a primary means for the pathogen to spread. studies soon found that the virus seemed to survive on some surfaces, including plastic and steel, for up to three days. (studies later showed that much of this is likely to be dead fragments of the virus that are not infectious.) t h e w o r l d h e a l t h organization also emphasized surface transmission as a risk, and said that airborne spread was a concern only when health care workers were engaged in certain medical procedures that produce aerosols. but scientific evidence was growing that the virus could stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhaled - particularly in crowded indoor spaces with poor ventilation. in july, an essay in the lancet medical journal argued that some scientists had exaggerated the risk of coronavirus infection from surfaces without considering evidence from studies of its closely related cousins, including sars- cov, the driver of the 2002-03 sars epidemic. “this is extremely strong evidence that at least for the original sars virus, fomite transmission was very minor at most,” the essay’s author, the microbiologist emanuel goldman of rutgers university, said in an email. “there is no reason to expect that the close relative sars-cov-2 would behave significantly different in this kind of experiment,” he added, referring to the new coronavirus. a few days a! er dr goldman’s lancet essay appeared, more than 200 scientists called on the w.h.o. to acknowledge that the coronavirus could spread by air in any indoor setting. bowing to enormous public pressure over the issue, the agency acknowledged that indoor aerosol transmission could lead to outbreaks in poorly ventilated indoor places like restaurants, nightclubs, offices and places of worship. s o m e e x p e r t s s a y t h e y are especially concerned that coronavirus droplets could spread through air vents in offi ces, which are crowded because the city has not yet developed a robust culture of remote work. “people are removing masks for lunch or when they get back to their cubicle because they assume their cubicle is their private space,” said yeung king- lun, a professor of chemical and biological engineering at the hong kong university of science and technology. “but remember: the air you’re breathing in is basically communal.” * mike ives reported from h o n g ko n g, a n d a p o o r va mandavilli from new york.