When outdoor risk is lowest
Walking your dog, cycling, hiking on the trail or picnicking with members of your household or vaccinated friends are all activities where the risk of virus exposure is negligible. In this kind of situation, you can keep a mask on hand in your pocket if you are in a crowd or need to go indoors.
- On April 13, 2021, U.S. health agencies called for an immediate halt to the use of Johnson & Johnson’s single-dose Covid-19 vaccine after six recipients in the United States developed a rare disorder involving blood clots within one to three weeks of vaccination.
- All 50 states, Washington DC and Puerto Rico paused or recommended providers suspend use of the vaccine. 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.
- Fewer than one in a million Johnson & Johnson vaccinations are now being studied. If there really is a risk of blood clots from the vaccine – which has not yet been determined – the risk is extremely low. The risk of getting Covid-19 in the US is far higher.
- The break could complicate the country’s vaccination efforts at a time when many states are facing an increase in new cases and trying to counter vaccination hesitation.
- Johnson & Johnson had also decided to postpone the rollout of its vaccine in Europe due to concerns about rare blood clots, but it 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 virus variant that emerged there, suspended the use of the vaccine, and Australia announced it would not buy any doses.
“I think it’s a little too much to ask people to put on the mask when they go for a walk or run or bike,” he 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 outdoor masking has never been required. “We are in another phase of the pandemic. I think outdoor masks should not have been mandatory at all. This is not where the infection and transmission occur. ”
“Let me drive without a mask. Mask in your pocket, ”tweeted Dr. Nahid Bhadelia, an infectious disease physician and the medical director of the Special Pathogen Unit at Boston Medical Center. “Given how conservative I have been on my opinions all year, this should tell you how low the risk is in general for transmission outside for contact over short periods – and even lower after vaccination. Keep the masks on when you are quiet in a crowd and looking indoors. ”
To understand how low the risk of outdoor transmission is, researchers in Italy used mathematical models to calculate the time it would take for a person to become infected outdoors in Milan. They imagined a gloomy scenario in which 10 percent of the population was infected with Covid-19. Their calculations showed that if a person avoided crowds, it would take an average of 31.5 days of continuous outdoor exposure to inhale a dose of virus sufficient to transmit infection.
“The results are that this risk is negligible in the open air if crowds and direct contact between humans are avoided,” said Daniele Contini, senior author of the study and an aerosol researcher at the Institute of Atmospheric Sciences and Climate in Lecce, Italy.
Even as more infectious virus variants circulate, the physics of viral transmission outdoors have not changed and the risk of becoming infected outdoors is still low, virus experts say. Be aware of the number of infections in your community. If the number of cases increases, the risk of encountering an infected person increases.
When outdoor fun moves indoors
Dr. Cevik notes that debates about outdoor masking and articles showing photos of crowded beaches during the pandemic have left people with the false impression that parks and beaches are unsafe and distracted from the far higher risks of indoor transmission. Often, the indoor activities associated with outdoor fun – such as traveling unmasked in a subway or car to go hiking or dropping off at a pub after spending time on the beach – pose the highest risk. “People have barbecues outdoors, but then they spend time indoors chatting in the kitchen,” said Dr. Cevik.