Jewish communities should cover their shofar with a face mask before blowing, because it can blast coronavirus particles to worshipers, a leading Israeli immunologist has said, as an American synagogue group also urged masking the ram’s horn.
“Attaching a face mask to a shofar is a good idea, and should really limit the spread of droplets,” said Cyrille Cohen, explaining that it should be fixed to the wide opening that the sound emanates from.
“Of course, it should be tight,” added Cohen, a long-time shofar blower, as well as head of the immunotherapy laboratory at Bar Ilan University in Ramat Gan and a member of the Health Ministry’s advisory committee on vaccines.
He said the rationale is that anybody can turn out to be an asymptotic carrier, and if a shofar blower turns out to be infected, the least exposure people have had to their germs, the better.
In America, the Orthodox Union has issued guidelines saying that “an appropriate precaution during shofar blowing would be to place a surgical mask over the wider end of the shofar, as this does not appear to alter the sound of the shofar blast.”
Jewish communities around the world will start daily shofar blasts on Friday, lasting for a month in the buildup to Rosh Hashanah, when it is traditionally blown around 100 times on each of the two days.
In Israel and various other places, restrictions limiting the size of synagogue services are expected to stay in place over Rosh Hashanah, but congregations are still expected to meet. Many communities are opting to hold at least some prayers outdoors, where the spread of coronavirus is reduced.
Most congregations will blow the shofar only on one day of Rosh Hashanah this year, as the first of the two days is Shabbat.
There is no single rabbi with universal authority on Jewish law and, with the idea newly mooted, it is too early to know if there will be objections to covering the shofar with a mask. But the Israeli Orthodox rabbi and Talmud scholar Jeffrey Woolf said there are little grounds to oppose the practice from a halachic viewpoint, calling it a “very smart idea.”
He said there is “absolutely no question and no problem,” explaining: “As long as the sound that comes out is authentic it is 100% fine.”
Cohen said he fears that as well as spreading infected droplets, some droplets from the blower could turn into aerosols.
“By adding force you can turn them into aerosols, theoretically,” he said, explaining that, smaller than droplets, aerosols “are more problematic because they could linger in the air.”
Two of the world’s top researchers on musical instruments and the pandemic think he is correct.
Adam Schwalje, a fellow with America’s National Institutes of Health who is based at the University of Iowa Hospitals and Clinics, told The Times of Israel that he has explored a variety of instruments, and found they spread both droplets and aerosols.
“A risk is involved with sounding the shofar,” he said, suggesting that its danger level is similar to that of the flute, with he has looked at in detail.
Schwalje, who is Jewish and familiar with the shofar, said that earlier research intensifies his belief that the horn may pose an infection risk.
A 2011 study was conducted on the vuvuzela, a simple plastic horn sometimes blown at soccer matches, and its ability to spread aerosols that could infect people with various germs. It found that “these plastic trumpets provide an excellent means of propagating respiratory aerosols, exceeding both sneezing and coughing as a means of disseminating droplet nuclei.”
Schwalje said: “I both fear and suspect that the shofar would be similar to the vuvuzela in terms of how much aerosol is created, though of course it would need to be tested to give any degree of certainty.”
Schwalje, together with Henry Hoffman, authored a set of protocols for musicians that are being widely followed. Published under the title “Wind Musicians’ Risk Assessment in the Time of COVID-19,” they have become the go-to source for American musicians wanting safety guidance.
Hoffman, professor of Otolaryngology at the University of Iowa Hospitals, told The Times of Israel that quarantining shofar blowers before they blow may be in order. “Serial testing and quarantining the ram’s hornblower prior to the event may help mitigate risk,” he said.
Schwalje and Hoffman aren’t the only experts who highlight the value of covering instruments. A team of researchers at the University of Colorado Boulder had musicians enter a room and analyzed the air. Their initial results, released online but not peer-reviewed, indicated that instruments produce aerosols in various sizes that can carry the COVID-19 virus, and found that they can stay airborne for minutes.
They found that cloth covers for instruments, and even a sack to cover an entire clarinet, reduced the spread of aerosols.
Cohen, the Colorado researchers and the Orthodox Union all recommended that as well as covering shofars, blowers ensure they never share shofars and maintain distance from their congregations. They also say outdoor prayers are best. The Orthodox Union suggested that the shofar should be pointed out of a window or door, or toward the front wall of the synagogue where people don’t normally sit.
Cohen said that he recommends shofar blowers stay further from worshipers than the two meters recommended for normal interactions. “I would say that since there are no definitive studies on shofars, a few more meters would be advised,” he said.
Schwalje agreed, saying: “More distance is probably better in most cases as airborne particles will tend to decrease in concentration as distance increases. Moreover, the other thing that distancing ensures is a limitation on the number of people in a space. Fewer people means less risk.”