(CNN) Practice social distancing, wear a mask, wash your hands (for at least 20 seconds) -- the recommendations to prevent coronavirus are a familiar refrain to most Americans.
There's little guidance, though, when it comes to sex in the age of Covid-19.
So three Harvard physicians examined the likelihood of coronavirus infection in a number of sex activities. And to better prevent infection during sex between partners who haven't been isolating together, people should wear masks and avoid kissing, the authors write.
These and more recommendations were published in the Annals of Internal Medicine.
Coronavirus's sexual transmissibility hasn't been rigorously studied, but we do know that it's a highly contagious respiratory illness that spreads through droplets like coughs, sneezes and spit.
"The sexual health implications of these recommendations have received little attention, even though it appears that all forms of in-person sexual contact carry risk for transmission of the virus," said Dr. Jack Turban, study lead author and resident at Harvard Medical School, where he studies the mental health of transgender youth.
Sex puts partners within close proximity, so partners are likely to be exposed to those droplets. And since an estimated 35% of coronavirus patients are asymptomatic, sex could provide the prime conditions for infection.
The study maintains that abstinence offers the lowest risk of infection, but the authors acknowledge that it's not a realistic option for many. What's more, the idea of sex as "dangerous" could have "insidious psychological effects at a time when people are especially susceptible to mental health difficulties," the authors say.
So the study takes a sex-positive approach. To better prevent infection, the authors write, people can reduce their number of sexual partners and avoid sex with people who show symptoms of Covid-19, including fever, cough, fatigue and loss of taste or smell.
In addition to wearing masks, people who have sex with partners outside of their home should also shower before and after, avoid sex acts that involve the oral transmission of bodily fluids and clean up the area afterward with soap or alcohol wipes to reduce their likelihood of infection.
The researchers also include recommendations for masturbation and digital sex, though people who engage in the latter should be aware of the security risks involved, the researchers said.
Sex between partners who've isolated together still presents some risk, because one partner might've been exposed to the virus if they've left the shared home. The researchers didn't recommend a mask for partners in this situation, though.