Vaccination programmes around the world have been shown to be reducing COVID-19 transmission rates and hospital admissions. But news of COVID variants emerging — and spreading fast — is still a concern. Viruses mutate; this is to be expected. And, as the coronavirus spreads and infects more people, it will be given more opportunity to do so, particularly in countries that have been slow to lock down, enforce social distancing or close borders. Mutations are random changes in the DNA of the virus that can alter its shape and the way it behaves. When a virus infects a human cell, its main job is to replicate and then spread. The virus instructs the infected cell to start making more copies of itself that then go on to infect other cells and are eventually coughed, sneezed or breathed out, enabling them to infect other people. Replication of the virus occurs at a relatively quick rate, however, which means errors can occur. Most of these errors are either harmful to the virus or have no effect, but as time goes on, the chances of an “advantageous error” — one that might make the original virus more powerful or infectious — occurring increase. Here are the new variants the experts are keeping an eye on. Brazil variant Something terrible is happening in Brazil. The country, which suffered horrific losses during the painful first wave of COVID-19, now finds itself entangled in an even worse second wave. After the US, Brazil (population 213 million) has one of the worst COVID-19 death tolls in the world, with more than 11 million people testing positive and more than 270 000 dead. Brazil’s leader, President Jair Bolsanaro, appears to have his head buried firmly in the sand as, in the past, the dismissed COVID-19 as a “little flu”. He has also repeatedly appeared in public without a face mask. Recently he went to the midwestern state of Goiás, where nearly 9 000 people have died, and told people to “stop whining” about the coronavirus outbreak, a move that was widely condemned by other countries. Furthermore, the rollout of vaccines in the country has been beset by supply problems and bottlenecks in the delivery process, as well as by false rumours such as one claiming the vaccine will turn people into animals. To make matters worse, a new variant — known as the P1 variant — has now emerged. It was first identified in the Amazonian city of Manaus in December and is thought to be more infectious than the original virus, enabling it to become the dominant strain. There is no evidence yet that this variant will make you more unwell, but as the virus is likely to infect more people this, inevitably, will result in more deaths. More than 2 000 deaths a day are already being recorded in Brazil, largely as a result of this new strain. It is spreading fast. Since December, the World Health Organisation (WHO) has identified it in other countries, including Canada, the United States, the United Kingdom, France, Germany, Spain, Japan, Mexico, India, Italy and the Republic of Korea. The new variant has overwhelmed hospitals in Brazil. W