Aug 1, 2019

Axios Science

By Alison Snyder
Alison Snyder

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  • Smart Brevity count: 1,226 words, < 5-minute read.
1 big thing: One year on, no end in sight for Ebola outbreak

Health workers carry a coffin containing a victim of Ebola virus in Butembo in May. Photo: John Wessels/AFP/Getty Images

One year ago today, the Democratic Republic of the Congo declared an outbreak of Ebola.

  • Since then, more than 1,800 people have died, the virus has been carried to the
    large city of Goma on the border of Rwanda and to nearby Uganda, and violence has killed health workers, Eileen Drage O'Reilly and I write.

The big picture: Politics, violence and community suspicion are thwarting efforts to contain the virus, which shows no signs of abatement.

The latest: 3 more cases of Ebola were confirmed this week in Goma, bringing the total to 4 in the city.

There are several experimental vaccines for Ebola, but only one — made by Merck — is currently approved for use in the DRC.

  • Preliminary results indicate it's highly effective, but there are limited supplies for now. (Merck tells Axios it has donated more than 210,000 doses to WHO since last year, and forecasts providing another roughly 900,000 over the next 6 to 18 months).
  • WHO and other groups have been recommending the DRC test other vaccines, including one made by Johnson & Johnson.
  • But, while Merck's one-dose vaccine takes about 10 days to provide immunity to most people, Johnson & Johnson's vaccine isn't completely effective for about 56 days and requires follow-up to administer two doses.
  • The DRC agreed to halve each dose of Merck's vaccine (to 0.5mL), which doubled the supply while still being effective.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, tells Axios that by halving the doses "we're not going to run out of vaccine for a while."

"The biggest challenge is insecurity," says Ben Dahl, who returned recently from the DRC where he served as response lead for the Centers for Disease Control and Prevention.

  • It stems in part from skepticism in the community about the existence of the outbreak, suspicion of sudden international interest in the much-neglected region and rampant misinformation about Ebola treatment centers.
  • This hinders efforts to contain the deadly virus by quarantining suspected cases and tracing, vaccinating and monitoring anyone who had contact with a person infected with the virus.

Another issue is the lack of financial tracking of funding for an outbreak "rumored to cost $1 million a day," says Jennifer Nuzzo, a senior scholar at Johns Hopkins' Center for Health Security.

  • Uncertainty over how the new leadership at the ministry and the Ebola effort also complicate the scenario, although she says people are "optimistic so far."
  • But, the strife over adding a second vaccine is "creating a worrisome scenario," she adds."There's a [vaccine] battle being set up here .... It will only fuel skepticism and exacerbate vaccine hesitancy."
2. Ebola outbreak, by the numbers
Expand chart
Data: DRC Ministry of Health; Chart: Andrew Witherspoon, Harry Stevens/Axios

The current Ebola outbreak in the DRC is the country's 10th since 1976 — and the worst in its history.

  • In the past year, the DRC reports there have been 2,701 accumulated cases (2,607 confirmed and 94 probable).
  • In total, there were 1,813 deaths (1,719 confirmed and 94 probable).
  • 776 people were cured.

For comparison, there were 318, 317 and 264 cases reported in outbreaks of the virus in the DRC in 1976 (the first), 1995 and 2007, per WHO.

  • The deadliest outbreak of the disease, which killed more than 11,000 people, was in West Africa in 2014-2016.

The big picture: Efforts to fight Ebola in the DRC are hindered by a parallel outbreak of measles, other diseases, misinformation and insecurity in the region.

3. The Milky Way in 3D

Milky Way map. Credit: J. Skowron/OGLE/Astronomical Observatory, University of Warsaw

A new 3D map of the Milky Way reveals the structure of our galaxy as never before, according to a new study, Axios' Miriam Kramer reports.

Why it matters: By modeling the Milky Way, scientists can piece together the galaxy’s history, explaining why it looks the way it does and placing it in context with other galaxies observed around our own.

What they found: The new study, published today in the journal Science, confirms the Milky Way’s disk appears to be warped in an extreme way.

  • “We don't know for sure, but we think that the warp may have been caused by interactions with satellite galaxies,” Dorota Skowron, one of the study’s authors tells Axios via email. “Other possibilities point to interactions with intergalactic gas or dark matter.”
  • The team measured the distances from the Sun to more than 2,400 pulsing stars called Cepheids in order to map the galaxy from the inside out.
  • They found the Milky Way does have four arms arranged in a spiral structure, as earlier studies have suggested.

What’s next: Mapping variable stars like Cepheids on the other side of the Milky Way’s center could inform future research about the shape of our galaxy, astrophysicist Richard de Grijs, who didn’t take part in the new study, tells Axios via email.

4. Worthy of your time

Illustration: Rebecca Zisser/Axios

The future of asteroid tracking (Miriam Kramer — Axios)

Obituary: Chaser, "the world's smartest dog" (Derrick Bryson Taylor — NYT)

The geology of geopolitics (Steve LeVine — Axios)

Japan approves first human-animal embryo experiments (David Cyranoski — Nature)

A new science of progress (Patrick Collison and Tyler Cowen — The Atlantic)

5. Something wondrous

A turtle embryo. Photo: Du et al./Chinese Academy of Sciences

Turtle embryos appear to be able to move within their eggs to temperature sweet spots that influence their sex, a new study reports.

The big picture: The sex of some turtle species is determined by the nest's temperature. The turtles can control that temperature a bit — by changing the time of season they are active or choosing their nesting sites accordingly.

  • But the eggs of turtles are "stuck wherever mom puts them, which makes them really susceptible to climate change," says Eric Gangloff, an assistant professor of zoology at Ohio Wesleyan University who wasn't involved in the study.

How it works: For the Chinese pond turtles (Mauremys reevesii) studied, the pivotal temperature — at which females and males are produced at a population-sustaining ratio of 1:1 — is about 29°C.

  • Two degrees warmer and all the offspring are female, with potentially "catastrophic population declines," the authors write in the journal Current Biology.
  • That pivotal temperature can evolve over time, explaining why turtles, among Earth's longer inhabitants, have survived natural climate changes in the past.

What they found: Wei-Guo Du of the Chinese Academy of Sciences and his colleagues report the temperature inside eggs of the species' could vary as much as 4.7°C during development.

  • The embryos moved about 4mm on average in response to different temperatures and, when they hatched, yielded an equal number of males and females.
  • Embryos in eggs treated with a chemical that blocks their ability to sense temperature moved half as much on average and were largely male or female, depending on the nest temperature.

Yes, but: Some researchers are skeptical of the results. They question how long embryos can move inside the egg as they develop and whether the turtles can coordinate that movement as the study implies, reports Science's Katie Camero.

  • And, "that control over sexual destiny has limits," the researchers write. Under projected climate change scenarios, for example, the ability to move around the egg isn't likely to help the turtles maintain their populations.

The bottom line: "Maybe it will help them hang on for a little while longer, but unless broader action is taken, it won’t matter in the long run," says Gangloff.

Alison Snyder