Start of hayfever season increases your risk of Covid, docs warn – even if you’re NOT allergic
HAYFEVER season increases your risk of picking up Covid, even if you don’t have the allergy, doctors have warned.
Their advice is to stay indoors when the pollen count is high between March and September to prevent picking up the coronavirus.
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In a new study, researchers looked at how the number of coronavirus cases increased in response to rising or falling pollen levels.
The takeaway of the study was that pollen can exacerbate Covid-19.
The team studies 31 countries – including the UK, US, Spain, Italy, Australia, South Africa and Canada.
On average, 44 per cent of the variability in Covid case rates was linked to pollen exposure – which is also what causes hayfever.
Infection rates spiked four days after there was a high pollen count – the lag is due to the time it takes for symptoms to show.
Case rates went up by four per cent when there was a spike in pollen levels.
But if there was strict lockdown, restricting people’s contact with friends and family, the impact was reduced by half.
The published research paper, in the journal PNAS, said there was “a robust and significant positive correlation between SARS-CoV-2 infection rates and airborne pollen concentrations”.
Plant physiologist Lewis Ziska, who led the research, said it wasn’t just a problem for those with hayfever, who are allergic to pollen.
Everyone inhales pollen for the outdoor air but it won’t necessarily cause allergic symptoms such as a cough, runny nose and itchy eyes.
Pollen ‘dampens the immune system’
A study by the same research team prior to the pandemic showed pollen can suppress the immune system by “significantly reducing” immune cells.
It means it may struggle to respond to viruses as quickly.
Their paper in 2018 said GPs are more likely to see people with severe respiratory tract infections during the early spring.
With millions of Brits still waiting for their vaccine over the spring and summer months, the risk of catching Covid is still real.
Dr Ziska wrote for ScienceAlert: “On days with high pollen counts, try to stay indoors to limit your exposure as much as possible.
“When you’re outdoors, wear a mask during pollen season.”
Although the findings suggest going outdoors in the spring and summer months could increase your risk of catching Covid, science generally suggests the opposite is true.
Pollen is only one environmental factor to consider.
Sunlight is thought to damage viral particles, which may be one reason Covid cases came down during the UK’s last summer.
And scientists say wind helps to blow viral particles away, so it’s best to meet a friend for a walk in the park than at your home.
Scientists agree that socialising outdoors is much safer than indoors, where there is a lack of ventilation.
So although pollen may reduce your ability to fight off Covid, there is a lower risk of you picking it up outdoors in the first place.
Know the signs
Experts have previously warned that symptoms of Covid could be mistaken for hayfever.
A cough and loss of smell can be present in both hayfever and Covid sufferers.
But a high temperature is unique to Covid, while itchy eyes and sneezing is more likely to be hayfever.
Hay fever affects up to one in five Britons.
The traditional hayfever period used to span just over a month – from mid June to mid July.
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But it can now last from March until September, with an additional three weeks compared to 30 years ago, according to a recent study.
What is more, there is over a fifth more pollen in the air – and the amount is going up.
The phenomenon has been blamed on burning of fossil fuels, cutting down rainforests and farming livestock.