Will Covid-19 vaccines protect you against variants? 9 questions about variants, answered.

Covid-19 vaccines remain the best tool to contain the spread of new variants of the virus. | Chip Somodevilla/Getty ImagesHow coronavirus variants are affecting vaccines, treatments, and our attempts to return to normal. The Covid-19 pandemic now appears to be the worst it has ever been, with daily new cases worldwide topping 800,000 several times over the past week. More new cases have been reported in the past two weeks than in the first six months of the crisis. More than one in three of these new cases were reported in India, the world’s second-most-populous country and now the epicenter of Covid-19. The rising infections, deaths, and strained health system have created a humanitarian crisis, one that may not relent for months. Other parts of the world that have barely begun to vaccinate people may soon see their own surges in Covid-19. What’s complicating the situation is the rise of new variants of SARS-CoV-2, the virus that causes Covid-19. Several of these variants contain mutations that can make prior immunity less effective, allow the virus to spread more readily, and, in some cases, cause more deaths. And the more the disease spreads, the more variants can arise. The SARS-CoV-2 variant first identified in India last year, called B.1.617, has already become the dominant version of the virus in some parts of the country and could be a driver, among others, of the current outbreak. And it’s one reason countries are now imposing travel restrictions on flights from India. Other variants have already arisen independently in different parts of the world and have rapidly gained ground, too. The World Health Organization (WHO) is now tracking 10 SARS-CoV-2 variants internationally. It may be hard to grasp the current scale of the pandemic from the US, which has so far managed to fully vaccinate at least one-third of its population while seeing precipitous drops in new cases, hospitalizations, and deaths. All three of the vaccines that have begun distribution in the US have proven to be highly effective at preventing hospitalizations and deaths from Covid-19, the worst consequences of the disease. However, the US can’t afford to be complacent. Several of these more dangerous variants have already arrived in the US. The Centers for Disease Control and Prevention (CDC) released new Covid-19 models and found that variants are poised to drive an increase in new cases in May. The challenge now is to vaccinate people to contain the spread of the virus, not just in the US but around the world. As long as the virus is spreading anywhere, it can mutate in threatening ways. But variants aren’t the only factor at play; public health measures and political will to contain the disease will also shape the remainder of the pandemic. How these factors are converging can be confusing, so here are nine questions and answers that may clarify some of the concerns: 1) What is a variant? Viruses mutate all the time, making mistakes in copying their genetic code as they replicate. Most of these mistakes are actually detrimental to the virus or have no effect. But in rare cases, a change in the genetic code can occur that confers an advantage to the pathogen, changes how it functions, or makes it harder to counter. The term “variant” refers to a virus strain with a distinct grouping of mutations. Sometimes these variants contain dozens of individual mutations compared to the original strain of a virus. The combination of mutations in these variants may even be working together, making the variants more dangerous than versions of the virus with individual mutations. Variants of SARS-CoV-2 have arisen at several points during the pandemic, but what’s concerning about the variants spreading right now is that they seem to be better able to spread. Some also seem to lead to more severe outcomes from Covid-19. And several variants seem to be better able to evade the immune system in people who were already infected or in people who have been vaccinated. So variants can increase the chances of a Covid-19 survivor getting reinfected or raise the likelihood of a breakthrough infection in someone who received a vaccine. 2) Why did variants show up all of a sudden? There are several factors behind why so many SARS-CoV-2 variants have emerged. One is simply that the virus has been spreading to more people in more countries. With more infections, there are more mutations, thereby creating a greater likelihood of a rare combination of those mutations converging in a way that poses a threat. Selection pressure is playing a role, too. As more people gain immunity through infection or vaccination, the variants that can evade that immunity remain and can circulate. “It is not an accident that these variants first arose in areas that have a record of poor implementation of measures to mitigate spread and very high rate of infection,” said Theodora Hatziioannou, a research associate professor of retrovirology at the Rockefeller Universit

May 6, 2021 - VOX
Covid-19 vaccines remain the best tool to contain the spread of new variants of the virus. | Chip Somodevilla/Getty ImagesHow coronavirus variants are affecting vaccines, treatments, and our attempts to return to normal. The Covid-19 pandemic now appears to be the worst it has ever been, with daily new cases worldwide topping 800,000 several times over the past week. More new cases have been reported in the past two weeks than in the first six months of the crisis. More than one in three of these..