When the risk is lowest outdoors
Taking your dog for a walk, cycling, walking a path, or having a picnic with members of your household or vaccinated friends are all activities where the risk of exposure to viruses is negligible. In situations like this, you can keep a mask in your pocket, in case you are in a crowd or need to go inside.
- On April 13, 2021, US health authorities called for an immediate discontinuation of Johnson & Johnson’s single-dose Covid-19 vaccine after six recipients in the United States developed a rare blood clot condition within one to three weeks of vaccination.
- All 50 states, Washington, DC and Puerto Rico has temporarily discontinued use of the vaccine or recommended providers. The U.S. military, federally-run vaccination sites, and a host of private companies, including CVS, Walgreens, Rite Aid, Walmart, and Publix, also stopped the injections.
- Less than one in a million vaccinations for Johnson & Johnson is now being investigated. If there is indeed a risk of blood clots from the vaccine – which has yet to be determined – that risk is extremely low. The risk of getting Covid-19 in the United States is much higher.
- The pause could complicate the nation’s vaccination efforts at a time when many states are facing an increase in new cases and the reluctance to tackle vaccinations.
- Johnson & Johnson had also decided to delay the rollout of its vaccine in Europe due to concerns about rare blood clots, but later decided to resume its campaign after the European Union’s drug regulator said a warning label should be added. South Africa, devastated by a more contagious variant of the virus emerging there, suspended use of the vaccine and Australia announced it would not purchase doses.
“I think it’s a bit too much to ask people to put on the mask when they go for a walk, jog or bike ride,” said Dr. Muge Cevik, a clinical lecturer in infectious diseases and medical virology at the University of St Andrews School of Medicine in Scotland, where masking outdoors has never been necessary. “We are at a different stage of the pandemic. I think outdoor masks shouldn’t have been mandatory at all. It’s not where the infection and transmission takes place. “
‘Let me run without a mask. Mask in pocket, ”tweeted Dr. Nahid Bhadelia, an infectious disease physician and the medical director of the specialty pathogens division at Boston Medical Center. “Given how conservative I have been about my opinion throughout the year, this should tell you how low the risk overall is for transmission outdoors for short-term contact – and even lower after vaccination. Keep the masks on when you are standing still in a crowd and entering. “
To understand how low the risk of external transmission is, researchers in Italy used mathematical models to calculate how much time it would take to become infected outside in Milan. They envisioned a grim scenario where 10 percent of the population was infected with Covid-19. Their calculations showed that if a person were to avoid crowds, it would take an average of 31.5 days of continuous outdoor exposure to inhale a dose of virus sufficient to transmit an infection.
“The results are that this risk is negligible in the outdoors when crowding and direct contact between people is avoided,” said Daniele Contini, senior author of the study and aerosol scientist at the Institute of Atmospheric Sciences and Climate in Lecce, Italy.
Even with more contagious virus variants circulating, the physics of outdoor viral transmission has not changed and the risk of getting infected outdoors is still low, virus experts say. Pay attention to the infection rate in your community. As the number of cases increases, your risk of encountering an infected person increases.
When outdoor fun moves indoors
Dr. Cevik notes that debates about outdoor masking and articles featuring photos of crowded beaches during the pandemic have given people the wrong impression that parks and beaches are unsafe, distracting from the much greater risks of indoor transmission. Often times, it is the indoor activities associated with outdoor fun – such as unmasked traveling in a subway or car to go for a walk, or walking into a pub after spending time on the beach – that pose the greatest risk. “People have barbecues outside, but then they spend time inside chatting in the kitchen,” said Dr. Cevik.