Stories by Sara Reardon

A federal judge in Texas ruled to withdraw the Food and Drug Administration’s approval of the abortion drug mifepristone, potentially making medication abortion less accessible nationwide

As more people turn to chat-based AIs for medical advice, it remains to be seen how these tools stack up against—or could complement—human doctors

The risks associated with a bone marrow transplant used to treat HIV mean the procedure is unlikely to be widely used in its current form

With cases declining in the U.S. and Europe, here are some scenarios of how the outbreak might play out

An unvaccinated person in New York State’s Rockland County developed paralysis from a polio infection, emphasizing the need to target vaccination efforts to vulnerable communities

The virus circulating in the current outbreak has mutated 50 times in the past four years

The model, which uses machine learning to track the fitness of different viral strains, accurately predicted the rise of Omicron’s BA.2 subvariant and the Alpha variant

States that outlaw abortions after a certain number of weeks could make it difficult or impossible to terminate a pregnancy because of a serious genetic disorder

Results from a large study suggest that vaccines offer less protection against lingering symptoms than expected

The Biden administration’s Test to Treat program aims to make the treatments available at pharmacies, yet it requires a medical provider to prescribe the drugs

A CDC database of sewage data from communities around the nation could provide earlier warning of outbreaks and new viral variants

A handful of experiments are raising questions about whether clumps of cells and disembodied brains could be sentient and how scientists would know if they were

It depends, but vaccinated people should generally wait five days after exposure before taking an antigen test. Here’s why

If the Supreme Court overturns Roe v. Wade in a Mississippi abortion case, numerous state laws will interfere with key biological and social decisions during pregnancy

Wealthy countries have bought up most of the available vaccine doses for booster shots but still have far more than they need

Experts explain what this treatment involves, who needs it and how to get it

A tool built by the U.S. Geological Survey suggests that the number of fatalities may range from 10,000 to 100,000 or more

Mutations that make a virus more transmissible are only part of the equation

Viral load is roughly 1,000 times higher in people infected with the Delta variant than those infected with the original coronavirus strain, according to a study in China

The international collaboration does not have enough COVID vaccine doses to meet its goals, so wealthy countries must step up to fill the gap

The first successful clinical test of optogenetics lets a person see for the first time in decades, with help from image-enhancing goggles

The legislation runs counter to evidence that puberty blockers and hormone treatments are safe and save lives

The SARS-CoV-2 coronavirus seems to be suddenly acquiring mutations at a rapid rate. The most worrying variants, first discovered in South Africa and Brazil, increase the virus’s contagiousness and may even help it evade the human immune system. These characteristics are helping the new variants outcompete the original virus, allowing them to spread quickly around the world.

Viruses, including SARS-CoV-2, are constantly evolving and acquiring mutations that don’t affect the virus much. The reason public health experts are concerned is that the new mutations improve the virus’s spike protein, which helps the pathogen enter cells and is the target of most vaccines. If the spike protein evolves sufficiently, the virus may eventually be able to reinfect individuals who have already had COVID-19 or been vaccinated against it.

But scientists say it will likely be years before the vaccine stops working entirely—if it ever does. In the meantime, social distancing remains the best way to fight the new mutants. After all, the more viruses that exist in the world, the greater the chance that one will evolve a dangerous mutation.

In this video, we explain what the new variants actually are, how they arise and spread, and what they could mean for the future of our ability to vaccinate ourselves against the virus.

Here is a guide to novel versions of the COVID-causing virus—and genetic changes that can make them more contagious and evasive in the body