Dive Insight:

RSV is one of the most common, and confounding, viruses that cause infections in humans. There’s no approved vaccine and current treatment options focus on managing symptoms, much like a cold.

For most people who contract RSV, that’s enough; they generally suffer only cold-like symptoms. But the virus can be deadly for infants or the elderly. RSV leads to 58,000 hospitalizations of children younger than 5 every year in the U.S. and 177,000 hospitalizations among those 65 and older, according to the Centers for Disease Control and Prevention. The virus kills some 14,000 elderly Americans annually.

Scientists have been trying to develop a vaccine since the 1960s but failed to produce shots that were safe and effective. Pfizer is among several companies that have revived vaccine efforts, by targeting a viral protein that RSV uses to attack human cells.

Pfizer’s experimental vaccine is currently in Phase 3 testing, with results expected by the end of June. The company is studying the inoculation in seniors aged 60 and over, as well as in pregnant women, with an eye toward giving infants early protection against the virus.

GlaxoSmithKline also expects to get results soon from a Phase 3 study of its vaccine in people aged 60 and over. The company in February had to pause a trial of a related vaccine in pregnant women because an independent board monitoring the study became concerned about possible safety issues.

Johnson & Johnson, meanwhile, expects to finish its vaccine trial in people 60 and over next year. And Moderna, which is using a different technology than the three major drugmakers, got clearance in February to kick off a Phase 3 trial of its entry.

Though far from huge, the Pfizer-ReViral deal ranks as one of the largest so far this year in the biotechnology industry. After several booming years, mergers and acquisitions dipped dramatically in 2021 and have yet to resurge.