Coming as it does at a time when COVID-19 resolutely refuses to pack up and go away, the 2021 United Nations Climate Change Conference (COP26) in Glasgow this November will likely discuss not only international climate action but the impact of climate on health issues as well. As the Lancet Countdown 2020 Report explained, no continent, country, or community is immune from the health impacts of the climate crisis.
The COP26 Special Report has linked the roots of the health crisis to the destruction of biodiversity, the climate emergency and particularly to air pollution. A study published in Science, “Ecology and Economics for Pandemic Prevention,” has found that the costs of preventing future zoonotic outbreaks like COVID-19—by preventing deforestation and regulating the wildlife trade—are as little as $22 billion a year, 2% of the economic and mortality costs of responding to the COVID-19 pandemic, which some economists predict could reach $10-20 trillion. The paper, co-authored by the Director of the Harvard T.H. Chan School of Public Health, Dr Aaron Bernstein, outlines how stimulus funding should be used to reduce the risk of disease spillover from animals to humans. (Read now in Science) Some of the important points raised in the report are:
- Over the last 100 years, 2 viruses a year spillover from animals to humans.
- Locations near the edges of tropical forests where more than 25% of the original forest has been lost tend to be hotbeds for animal-to-human virus transmissions.
- Wildlife markets and the legal and illegal trade of wildlife for pets, meat or medicine increase transmission.
Dr Bernstein, in a “conversation” on environmental issues and COVID-19 published in the Harvard Public Chan website, has established firm linkages between environmental degradation and viral diseases ( “Coronavirus, Climate Change, and the Environment A Conversation on COVID-19 with Dr Aaron Bernstein, Director of Harvard Chan C-CHANGE”:
“As the planet heats up, animals big and small, on land and in the sea, are headed to the poles to get out of the heat. That means animals are coming into contact with other animals they normally wouldn’t, and that creates an opportunity for pathogens to get into new hosts.
Many of the root causes of climate change also increase the risk of pandemics. Deforestation, which occurs mostly for agricultural purposes, is the largest cause of habitat loss worldwide. Loss of habitat forces animals to migrate and potentially contact other animals or people and share germs. Large livestock farms can also serve as a source for spillover of infections from animals to people.”
Climate change has already made conditions more favourable to the spread of some infectious diseases, including Lyme disease, waterborne diseases such as Vibrio parahaemolyticus which causes vomiting and diarrhoea, and mosquito-borne diseases such as malaria and dengue fever. To help limit the risk of infectious diseases, we should do all we can to vastly reduce greenhouse gas emissions and limit global warming to 1.5 degrees.
We also need to take climate action to prevent the next pandemic. For example, preventing deforestation—a root cause of climate change—can help stem biodiversity loss as well as slow animal migrations that can increase the risk of infectious disease spread. The recent Ebola epidemic in West Africa probably occurred in part because bats, which carried the disease, had been forced to move into new habitats because the forests they used to live in had been cut down to grow palm oil trees.
Recent research from Rachel Nethery, Xiauo Wu, Francesca Dominici and others at Harvard Chan has found that people who live in places with poor air quality are more likely to die from COVID-19 even when accounting for other factors that may influence the risk of death such as pre-existing medical conditions, socioeconomic status, and access to healthcare.
The broad conclusion is that investing $22-31 billion a year to monitor and police the wildlife trade and curb tropical deforestation can help prevent future pandemics. Not much when the US is looking at a $ 65 billion package to tackle future pandemics and when the US administration has also estimated losses due to Covid-19 at $ 16 trillion so far.
Meanwhile, the New York Times reported on Friday that a key advisory panel to the Food and Drug Administration overwhelmingly rejected recommending Pfizer booster shots for most recipients of the company’s coronavirus vaccine. (https://www.nytimes.com/2021/09/17/us/fda-pfizer-booster-covid.html?)
While the vote — the first on boosters in the United States (US) — was a blow to the Biden administration’s strategy to make extra shots available to most fully vaccinated adults in the US eight months after they received a second dose, it partially endorsed the move allowing for boosters to be given only to people who are 65 or older or at high risk of severe COVID-19 and had received their second dose at least six months ago.
Committee members appeared dismissive of the argument that the general population needed booster shots, saying the data from Pfizer and elsewhere still seemed to show two shots protected against severe disease or hospitalization and did not prove a third shot would stem the spread of infection.
A welcome development for the World Health Organization (WHO) Director-General, Dr Tedros Adhanom Ghebreyesus, who has been outspoken in his opposition to booster shots at a time when COVAX the international vaccine initiative he’s spearheading is struggling hard to achieve a target of first jabs to 20% of the population in Africa. The fewer the boosters in the US and elsewhere, the more the availability elsewhere.
As if the different avatars of COVID-19 weren’t bad enough, an old “faithful” has turned up to make matters worse. There’s been a recurrence of the Nipah virus in the southern Indian state of Kerala, the third outbreak since 2018. And it couldn’t have come at a worse time. Kerala, known for its palm-lined beaches on the Arabian Sea, is still reeling with a caseload of 4 million coronavirus infections since the pandemic began, the US NPR reports (www.npr.org/sections/goatsandsoda/2021/09/12/1035571714/)
The Nipah virus is making news again after reports that a 12-year-old boy died from the virus on September 5 in Kerala’s Kozhikode district. The WHO classifies Nipah as a “virus of concern” for future epidemics because “each year it spills over from its animal reservoir into humans,” says Dr Stephen Luby, a professor of infectious disease at Stanford University. And when humans are infected, it can be transmitted from person to person.
“However, each time a person is infected, the virus is in an environment that selects for human adaptation and transmissibility. The risk is that a new strain that is more efficiently transmitted person to person could generate a devastating outbreak. Indeed, since 70% of people who are infected with Nipah virus die, such a strain could represent the worst pandemic humanity has ever faced,” Luby added.
Following the boy’s death, public health authorities swung into action, contact-tracing friends, family members and health workers. They identified and isolated 251 people, including 30 close family members. Eleven samples from those in close contact with the boy were sent for testing, and on September 8, they were negative. But how this child contracted Nipah is still unclear.
“It’s really difficult to establish the cause of the boy’s illness,” says Dr Thekkumkara Surendran Anish, associate professor of community medicine at the Government Medical College in Thiruvananthapuram. “The infected patient was just too sick to tell us anything about what he ate or did. That’s why it’s all speculation.”