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Many countries have started to lift restrictions and open up their borders, but that doesn’t mean it’s safe to hop on a flight overseas just yet. Cold weather is rolling in, cases are still going up, and it’s as important as ever that you wear a mask and keep your distance. Here’s some of the latest coronavirus news you need to know for the week.

Long-haul flights still pose a risk of infection to travelers

A new study from the Centers for Disease Control and Prevention (CDC) investigated the potential for in-flight transmission and found that on long-haul flights, COVID-19 can travel beyond the recommended spacing between seats.

The study identified a single symptomatic passenger flying from London to Vietnam on March 1 who transmitted the virus to 15 people on the flight. The woman was seated in business class, and of those who contracted the virus after the flight, 12 were seated in business class, two were passengers in economy class and one was a flight attendant in economy class.

The researchers believe that the virus was transmitted through aerosols or droplets, and that the reach from business to economy class may have been a result of a flight attendant using the business class restroom. It’s worth noting that at the time, face masks were not yet recommended on flights, which may make the results less relevant for current travelers—though it does emphasize why wearing a mask is so crucial. Planes have HEPA air filters and excellent circulation, but even so sitting near someone with COVID-19 for many consecutive hours is risky. Other passengers have caught the novel coronavirus on board flights, even when people are wearing masks.

The CDC finally acknowledged that the novel coronavirus can travel through the air, then revoked that guidance

On Friday, the CDC updated its guidelines to acknowledge that COVID-19 can, in fact, travel through the air—then, on Monday, removed this update and announced that it was a mistake. The reverted guidelines now only warn of spreading the virus through respiratory droplets, which are much larger than aerosol particles and are produced when an infected person coughs, sneezes or talks.

The now-removed update noted that the virus can be transmitted by simply breathing. It also warned that aerosols and droplets can travel distances longer than 6 feet and remain suspended in the air for extended periods of time, and asked people with symptoms to isolate at home. Before this update, the CDC recommended that people wear face masks, keep at least 6 feet of distance from others and wash their hands frequently. Those guidelines have not changed.

Scientists have been raising concerns about the possibility of airborne transmission since April. The World Health Organization updated its information to include the possibility of airborne transmission in July, but the CDC hasn’t followed suit until now.

An increase in stillbirths is worrying medical professionals around the globe

A series of reports from around the world has found that the proportion of pregnancies ending in stillbirths has risen by as much as 50% since the beginning of the pandemic in late March.

This trend appears not to be due to complications from COVID-19 itself, but rather as collateral damage of overwhelmed healthcare systems. As hospitals devoted more time and effort to controlling outbreaks, routine care during pregnancy often fell by the wayside and pregnant women hesitated to attend in-person appointments for fear of contracting the virus.

The WHO recommends that expecting parents attend eight prenatal appointments. During the pandemic, many of these appointments have gone online, which prevents healthcare workers from providing services—such as taking blood pressure and ultrasounds—that could identify risks to the fetus or mother.

The actual number of stillbirths, according to researchers, has remained constant throughout the pandemic, but far fewer women are going to the hospital to give birth. It’s possible that women with uncomplicated births might have opted to stay home, and that the proportion of stillbirths is only appearing to increase because statistics are collected at hospitals. But it’s also possible that women are opting for home births more overall, and that some of those have been stillbirths. Some of the hospitals in the study delivered half as many babies as would otherwise be normal, so there are certainly a lot of missing data points.

You may be safe from COVID-19 reinfection, but probably not for long

A 35-year study of the common cold may provide insight into whether people can get the novel coronavirus twice—and how long protective immunity might last.

The study, published in Nature last Monday, measured participants’ antibody levels for four strains of coronavirus to determine whether people can be infected by the same strain more than once, and how long it takes for a person to become reinfected. The study found cases of reinfection as soon as 6 months post-infection, but most often not until 12 months after (if reinfection occurred at all).

The researchers predict that immune responses to COVID-19 may follow similar patterns. It may be awhile before we know for sure whether it’s possible—or likely—to get infected twice. So far, there does seem to be at least one documented case of a reinfection with SARS-CoV-2, but it’s difficult to tell for sure whether the other reports are true reinfections.

A “report” on COVID-19 being made in a lab has been completely debunked

Virologists have known for a couple of months now that SARS-CoV-2 was probably circulating in bats for many years before making a recent jump into humans, but plenty of people have spread conspiracy theories about the virus being made intentionally in a lab somewhere in China. A National Geographic story last week took apart this particular report, but journalists everywhere have been combating this kind of misinformation since the pandemic began.