New strains of Covid-19, known as FLiRT variants, have been spreading globally, leading to concerns about a potential summer spike in cases. These variants are descendants of the JN.1 variant and are now becoming dominant strains in the U.S. and Europe. The mutations in the variants’ genetic code have caused them to independently pick up the same set of mutations. While there is currently little evidence to suggest that these new strains are more severe, cases are on the rise in several countries.
In the U.S., the KP.2 strain is now the dominant strain, accounting for 28.2% of all cases in the two weeks leading up to May 11. This is a significant increase from 3.8% at the end of March when the strain was first discovered. Another FLiRT variant, KP.1.1, is also on the rise, accounting for 7.1% of current infections. In Europe, the new variant has been detected in 14 countries, with the World Health Organization reporting limited cases in all reporting countries.
Despite the increase in cases of these new strains, the World Health Organization has noted that individual countries are seeing slight increases in detections from very low levels. The U.K. Health Security Agency continues to monitor data related to the new variants, assessing their severity and vaccine effectiveness. While it is unlikely that the new strains will cause a major wave of infections, there may be an uptick in cases during the summer months due to the mutations in the circulating strains.
Jennifer Horney, a professor of epidemiology at the University of Delaware, believes that the new strains will likely lead to an increase in the number of cases in the U.S. over the next few months. However, many of these cases are expected to be mild due to existing immunity rather than changes in the circulating strain. Health professionals are closely monitoring the effectiveness of current vaccines against the new variants, with the U.S. Food and Drug Administration’s vaccines advisory committee set to discuss recommendations for this winter’s Covid-19 vaccine next month after collecting more data.
