For the most up-to-date news and information about the coronavirus pandemic, visit the WHO website.
An open letter, signed by 239 researchers from 32 countries, sent to public health bodies, including the World Health Organization, on Monday argues there’s significant evidence the coronavirus can persist in the air and spread in tiny, airborne particles from person to person. The letter, published in the journal Clinical Infectious Diseases on Monday, advocates for “the use of preventative measures to mitigate this route of airborne transmission” and suggests re-examining the role of different transmission routes in the spread of disease.
The existence of the open letter was first reported by The New York Times and Los Angeles Times on Saturday, describing the WHO as an organization “out of step with science” on the matter. On Thursday, the WHO responded by updating its scientific brief on how the coronavirus is spread.
It notes the science isnt yet settled on whether SARS-CoV-2, the coronavirus that causes COVID-19, spreads effectively and causes disease via the air. And it appears it’s not a yes or no equation. Like many aspects of the pandemic, it’s a puzzle that remains unsolved.
CNET Science
From the lab to your inbox. Get the latest science stories from CNET every week.
“It’s possible and even likely that airborne transmission occurs for SARS-CoV-2 sometimes,” Babak Javid, an infectious diseases physician at the Tsinghua University School of Medicine, said in a statement. “It’s not at all clear how common this is.”
The WHO’s official guidance on the matter is the virus moves from person to person via “small droplets” that are expelled when a person with COVID-19 coughs, sneezes or speaks. These droplets are too heavy to travel great distances, sinking quickly to the ground. In addition, it states the virus can be picked up from surfaces. That’s why hand-washing and social distancing are important to help curb the spread.
But the signatories in the open letter argue SARS-CoV-2 lingers in the air, and this may play a role in transmission. They believe when a person with COVID-19 expels virus, the particles remain aloft and can travel great distances on air currents, particularly where ventilation is poor. “It is understood that there is not as yet universal acceptance of airborne transmission of SARS-CoV2; but in our collective assessment there is more than enough supporting evidence so that the precautionary principle should apply,” they write.
To mitigate the risk of airborne transmission, they propose two major measures should be implemented: Better ventilation in public buildings and reducing overcrowding. It also calls for the WHO to recognize this potential route of transmission and more effectively communicate the risks associated with it.
“We are concerned that the lack of recognition of the risk of airborne transmission of COVID-19 and the lack of clear recommendations on the control measures against the airborne virus will have significant consequences,” the researchers write. The WHO has been reticent to provide additional advice highlighting the risks, citing a lack of evidence.
Some scientists voiced concerns over the letter suggesting the concerns over airborne transmission may be overblown.
“I’m a bit shocked this came up,” says Isaac Bogoch, an infectious diseases researcher at the University of Toronto. “There is no new data, just a signed letter that makes headlines.”
Over the air
The debate is centered on interpretation of transmission modes, and this confusion extends to the public’s perception of how the disease spreads.
“A problem here is the potential conflict between the technical notion of airborne transmission and the perception of the general public about this term,” said Jose Vazquez-Boland, chair of infectious diseases at the University of Edinburgh.
The academic kerfuffle essentially pits “droplets” — the heavy particles that fall to the ground within six feet — against “aerosols” — light viral particles that remain suspended in the air. The key difference is the size of the particles.
“The size of [a] droplet is going to be really important, because all effectively have mass or weigh something,” explains Bruce Thompson, a respiratory expert at Swinburne University in Australia. The bigger respiratory droplets from something like a sneeze don’t stick around in the air long; they’re airborne, but they drop to the ground quickly because of gravity. Aerosols are different.
“If it’s an aerosol, it’s potentially going to be floating around the air more,” Thompson says.
These technical distinctions can make it hard for the general public to understand what it means for a virus to be “airborne.”
“For the public, it may be difficult to differentiate between the different situations and technical definitions,” Vazquez-Boland said.
You might immediately think just going for a jog or spending time outside could result in infection as COVID-19 particles make their way into your lungs, but it’s more likely the “airborne” route occurs in densely packed, indoors settings with poor ventilation. Whether you can be infected with SARS-CoV-2 is likely context-specific, and many factors will play a role. Some of this nuance is being lost in the academic to and fro and causing some of the public’s confusion over the spread of the disease.
“There is a bit of a false dichotomy between droplet and airborne transmission,” Bogoch said. “It’s more of a spectrum rather than silos.
“COVID-19 falls closer to the droplet end of the spectrum,” Bogoch said.
Even if the risk is understated or under-acknowledged by the WHO, it may not have a dramatic effect on combating the spread. The organization does recommend avoiding crowded places as part of their official guidance on protecting yourself from COVID-19. It also advises those who feel sick to stay home or wear a mask when leaving the house, another factor limiting the risk of airborne transmission.
For now, whether coronavirus is airborne, the guidance remains mostly the same. Avoid crowded indoor locations, or if you must be indoors, try to spend less time there. The virus may accumulate in poorly ventilated spaces, increasing the risk of infection.
You should continue to maintain social distancing measures. When you’re out, put on a mask. Wash your hands. And keep listening to advice from local health authorities with the caveat that information can — and will — change based on new evidence.
WHO comments
During a press briefing on Tuesday, journalists questioned the WHO about the New York Times report and the open letter, giving the organization a chance to speak publicly on the matter.
“We acknowledge there is emerging evidence in this field,” said Benedetta Allegranzi, a WHO technical lead in infection prevention and control. “We believe that we have to be open to this evidence and understand its implications regarding the modes of transmission.”
“As we’ve said previously, we welcome the interaction from scientists all over the world,” added Maria Van Kerkhove, technical lead on the COVID-19 pandemic. “We are also looking at the role of airborne transmission in other settings where you have poor ventilation,” she noted. Van Kerkhove noted the WHO had been working on a “brief” regarding transmission for several weeks. The organization released the brief on Thursday, July 9, which is an update on the “modes of transmission” statement from March 29.
The WHO now acknowledges the emerging evidence of airborne transmission provided by the open letter, but the organization’s new brief states patients with COVID-19 “primarily” infect others through droplets and close contact. The WHO hasn’t “reversed” its guidance, as some claim, but rather added to it based on new evidence (and the open letter), while acknowledging the evidence for airborne transmission remains slim and “transmission of SARS-CoV-2 by this type of aerosol route has not been demonstrated.”
How important this route is for spreading COVID-19 is still up for debate and the WHO’s updated brief states “urgent high-quality research is needed to elucidate the relative importance of different transmission routes.”
Updated July 7: Added WHO briefing comments. Updated July 9: Adds WHO scientific brief publication and comments, updated headline.
The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.
It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.
Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”
Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.
Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.
A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.
On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.
Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”
But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”
“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.
Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.
Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.
Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.
“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.
“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”
This report by The Canadian Press was first published Sept. 13, 2024.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.
The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.
Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.
“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”
The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.
A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.
Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.
“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.
Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.
The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.
“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.
This report by The Canadian Press was first published Sept. 11, 2024.
ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.
Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.
Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.
Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.
The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.
“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.
Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.
Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.
Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.
A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.
This report by The Canadian Press was first published Sept. 10, 2024.
