Hay fever season is back, much to the dismay of thousands of bleary-eyed and runny-nosed Brits. But could all that extra sneezing and coughing increase the spread of Covid-19 as more people socialise outdoors this spring?
Dr Daniel Atkinson, clinical lead at Treated.com and a GP, says hay fever sufferers should be mindful of keeping their coughs and sneezes under wraps to keep germs to themselves. “With high pollen counts usually setting in around this time of year, hay fever – particularly sneezing – could be an aggravating factor that causes some amount of spread in the coming weeks,” he says.
The main way coronavirus spreads is during close contact with others, so the idea is that increased sneezing and coughing – key symptoms of hay fever – could fuel the spread of the virus when people meet, particularly as one in three people with Covid-19 are thought to have no symptoms.
This spring – up until 17 May – people are only able to socialise outdoors, Boris Johnson’s roadmap states. They should social distance and practice good sneeze hygiene when doing so, says Dr Atkinson. “If the pollen forecast is high on a particular day and could put your sinuses through the wringer, maybe think about rearranging your walk for a different day,” he adds.
So how likely is it that hay fever could increase the spread Covid-19 outdoors?
Well, experts suggest outdoor transmission is pretty low. Speaking to HuffPost UK about the risk of catching Covid in busy parks, Paul Hunter, professor in Medicine at the University of East Anglia, said evidence shows transmission of Covid outside is much lower – about 19-fold less – than transmission indoors.
This doesn’t mean transmission outdoors is impossible, he said, “but it will be unlikely to play an important role in the spread of the epidemic”.
The highest risk of transmission outdoors is during face-to-face conversation between unmasked people, less than one metre apart, if there is less wind and less sunlight, added virologist Dr Julian Tang, from the University of Leicester. In these conditions, the virus can pass quickly between individuals through the air.
Dr Atkinson agrees you’re less likely to catch or spread coronavirus outdoors because it’s an open environment and virus particles can’t hang in the air as easily. “But it’s not impossible,” he warns. “And a high pollen count increases the risk. Researchers suggested Covid-19 particles can travel as far as eight metres when carried by a sneeze.”
There aren’t any specific studies on hay fever and Covid-19, yet – although “it would be an interesting area of study,” says Dr Simon Clarke, associate professor in cellular microbiology at the University of Reading, “because both have impact on inflammation response in our airways.”
He adds that while it’s true someone with Covid-19 sneezing more often as a result of hay fever could increase chances of transmission to others, there’s no evidence it actually does in the real world.
“Being outside and in moving air is one of the best ways to stay safe if you are alongside other people,” he says. “Of course, anyone sneezing should always follow good hygiene practice and use a tissue and wash hands.
“That’s sound health advice as well as just good manners.”
Hay fever hygiene in the pandemic
1. Always cover your mouth if you sneeze or catch it in a tissue.
2. Carry hand sanitiser with you when outside the house.
3. Check the pollen forecast before you make plans. If the pollen count is high and you get hay fever, it may be worth avoiding grassy areas or arranging a meet-up on a different day.
4. Remember to social distance and maintain two metres between you and others.
5. Get the vaccine when you are offered it. As well as protecting you, there’s early evidence to suggest that it also limits the risk you’ll spread the virus to someone else.