New variants of the SARS-CoV-2, the virus that causes COVID-19, have appeared to spread more easily. Some may cause more serious disease. Fortunately, current vaccines appear to be at least partially effective against these variants. The best way to protect yourself and others from COVID-19 is to get vaccinated as soon as you are eligible. The more people who are vaccinated, the fewer will get infected. This, in turn, will reduce the risk of new, deadlier variants arising and taking over.

In addition to working as a University of Washington Medicine infectious disease specialist, I collaborate with an international team on detecting new infectious disease threats, including new variants of known pathogens. The program, called United World Antiviral Research Network (UWARN), has experts at research centers in Africa, Asia, Europe, and North and South America. We set up the program in 2019 because of concern that the world’s ability to respond to pandemic threats was too slow and uncoordinated. Unfortunately, 2020 proved that to be correct.

Although we monitor and track a host of viral pathogens, we are currently focused on detecting and characterizing new SARS-CoV-2 variants. Our collaborators in the Republic of South Africa, led by Professor Tulio de Oliveira at the University of KwaZulu-Natal in Durban, first identified the B.1.135, a fast-spreading variant that is able to elude the body’s immune response in people who had been infected with previous versions of the virus and should have acquired some immunity. Our UWARN partners in Brazil, led by Drs. Luiz Alcantara and Marta Giovanetti at the Fundação Oswaldo Cruz in Rio de Janeiro, have shown that a variant first detected in that country, called P1, can reinfect people who had been infected with previous versions of the virus. Their research also suggests that variants tend to arise in communities where a large percentage of the population is infected. The finding suggests new variants can emerge even in communities where herd immunity has been achieved from natural infection.

The rise of more dangerous variants is not a surprise. Each time a virus makes a copy of itself, it generates a copy of the genetic instructions encoded in its genome. Often, while copying this code, mistakes are made. Most of these “typos” have no effect. But some change the way the virus behaves, making it better able to infect a cell, for example, or to elude the body’s immune response. When a change in the virus’ genetic code significantly changes its structure and function, it is called a variant. Through natural selection, first described by Charles Darwin, variants that can replicate more efficiently, spread from person to person or evade the immune response will come to predominate in a community.

Currently a number of variants are circulating in the United States and abroad that particularly worry experts. These include B.1.135 and P1, mentioned above, and B.1.1.7, which was first detected in Britain where its rapid spread caused a surge in the number of cases. Two of these variants, B.1.1.7 and B.1.135, have been recently detected in Washington state. Experts warn that if such variants are allowed to spread, the United States could see yet another surge of cases, hospitalizations and deaths in the coming months.

Fortunately, the three vaccines that have been approved for use in the United States are very likely effective in preventing serious illness caused by all the variants that have been identified so far. Indeed, these vaccines produce more effective immunity than COVID-19 illness itself. Vaccine developers are already designing vaccines that should be more effective against these variants should they be needed.

The emergence of variants should serve as a warning that we cannot become complacent. As UWARN’s partners in South Africa and Brazil have shown, variants tend to emerge in areas where infection rates are high: The more infections, the greater the chance that even more deadly variants might emerge. In a sense, we are now in a race with the virus, a race where we must suppress the coronavirus before it can generate new, more virulent variants.