This undated handout picture obtained with an atomic force microscopy released by Cell Press on March 6, 2026 shows a Vesicular Stomatitis Virus (VSV) with deltavirus (protrusion). Microbes still hold surprises. Researchers have just discovered how tiny viruses slip inside other viruses to penetrate and infect a cell. 'Deltaviruses are transmitted via a viral Trojan horse,' according to a study published on March 6, 2026 in Cell, one of the most prestigious biology journals, led by researchers from the CNRS. (Photo by Handout / Cell Press / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CELL PRESS / HANDOUT" - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This undated handout picture obtained with a negative-stain electron microscopy released by Cell Press on March 6, 2026 shows a Snake reptarenavirus with snake deltavirus. Microbes still hold surprises. Researchers have just discovered how tiny viruses slip inside other viruses to penetrate and infect a cell. 'Deltaviruses are transmitted via a viral Trojan horse,' according to a study published on March 6, 2026 in Cell, one of the most prestigious biology journals, led by researchers from the CNRS. (Photo by Handout / Cell Press / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CELL PRESS / HANDOUT" - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This undated handout picture released by Cell Press on March 6, 2026 shows a Snake reptarenavirus alone, without deltavirus. Microbes still hold surprises. Researchers have just discovered how tiny viruses slip inside other viruses to penetrate and infect a cell. 'Deltaviruses are transmitted via a viral Trojan horse,' according to a study published on March 6, 2026 in Cell, one of the most prestigious biology journals, led by researchers from the CNRS. (Photo by Handout / Cell Press / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CELL PRESS / HANDOUT" - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This undated handout picture obtained with a cryo-electron microscopy released by Cell Press on March 6, 2026 shows a "Pregnant" Vesicular Stomatitis Virus (VSV) with the protrusion corresponding to the deltavirus. Microbes still hold surprises. Researchers have just discovered how tiny viruses slip inside other viruses to penetrate and infect a cell. 'Deltaviruses are transmitted via a viral Trojan horse,' according to a study published on March 6, 2026 in Cell, one of the most prestigious biology journals, led by researchers from the CNRS. (Photo by Handout / Cell Press / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CELL PRESS / HANDOUT" - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This undated handout picture released by Cell Press on March 6, 2026 shows a normal Vesicular Stomatitis Virus (VSV) without deltavirus. Microbes still hold surprises. Researchers have just discovered how tiny viruses slip inside other viruses to penetrate and infect a cell. 'Deltaviruses are transmitted via a viral Trojan horse,' according to a study published on March 6, 2026 in Cell, one of the most prestigious biology journals, led by researchers from the CNRS. (Photo by Handout / Cell Press / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CELL PRESS / HANDOUT" - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This undated handout picture released by Cell Press on March 6, 2026 shows a Vesicular Stomatitis Virus (VSV) (elongated particle) and a rodent deltavirus. Microbes still hold surprises. Researchers have just discovered how tiny viruses slip inside other viruses to penetrate and infect a cell. 'Deltaviruses are transmitted via a viral Trojan horse,' according to a study published on March 6, 2026 in Cell, one of the most prestigious biology journals, led by researchers from the CNRS. (Photo by Handout / Cell Press / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CELL PRESS / HANDOUT" - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This undated handout picture released by Cell Press on March 6, 2026 shows a normal Vesicular Stomatitis Virus (VSV) without deltavirus. Microbes still hold surprises. Researchers have just discovered how tiny viruses slip inside other viruses to penetrate and infect a cell. 'Deltaviruses are transmitted via a viral Trojan horse,' according to a study published on March 6, 2026 in Cell, one of the most prestigious biology journals, led by researchers from the CNRS. (Photo by Handout / Cell Press / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CELL PRESS / HANDOUT" - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

LOS ANGELES, CALIFORNIA - MARCH 05: In an aerial view, Los Angeles Memorial Coliseum and the California Science Center in Exposition Park are shown on March 5, 2026 in Los Angeles, California. Exposition Park is expected to receive nearly $100 million in proposed funding for upgrades and renovations ahead of the FIFA World Cup 2026 and LA28 Summer Olympics. Los Angeles Memorial Coliseum will host the LA Fan Festival during the World Cup and will host the Track and Field competitions and Opening Ceremony in the LA28 Summer Olympics. (Photo by Mario Tama/Getty Images)