Washington, Jan 15 : Cases of and hospitalizations for respiratory viruses, including Covid, the flu and RSV, continue rising across the US, and some health systems have started returning to mask and limited-visitation policies as health officials warn that hospital capacity may become strained, the media reported. Vaccination rates for all three illnesses remain low, despite the efficacy of updated flu and Covid boosters and the entrance of new RSV vaccines for older and pregnant people, The Guardian reported. The US Centers for Disease Control and Prevention (CDC) has urged providers to administer more vaccines in light of the possibility of "more severe disease and increased healthcare capacity strain" from respiratory illness, especially in the wake of holiday gatherings. About 44 per cent of adults have received flu shots this season but less than half of that number -- about 17 per cent -- of Americans eligible for the updated Covid shots have received them, with only one in three nursing home residents being up-to-date. The updated Covid boosters protect well against currently circulating variants, according to early research, The Guardian reported. Only 17 per cent of adults 60 and up have received the new RSV vaccines, and Beyfortus, the new, highly effective treatment to prevent RSV among infants, has been very difficult to access, The Guardian reported. Hospital admissions for Covid are up 20.4 per cent from the previous week, and Covid deaths are up 12.5 per cent in the same time period, with more than 1,600 people dying from Covid in the week ending December 9, according to the last full data set from the CDC, The Guardian reported. /IANS