The Covid-19 pandemic killed off one strain of the flu, and that will change the next vaccines | CNN For 10 years, Americans have had access to flu shots that protect against four strains of the virus: two A strains and two B strains. Brenda Goodman CNN

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In 2020, all the precautions that helped people avoid Covid had an unexpected benefit: An entire branch of the flu’s family tree, a B strain that geneticists call the Yamagata clade, disappeared, and it hasn’t been detected since.

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US respiratory virus levels remain high as flu rises in central states Respiratory illness levels in the United States remained high but stable last week, with flu activity rising in some regions of the country and indicators declining for both COVID-19 and respiratory syncytial virus (RSV), the Centers for Disease Control and Prevention (CDC) said today in its latest data updates. CIDRAP

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Flu activity ticked down last week, but respiratory virus season is far from over in the US

The United States started the new year awash in respiratory illness, with high levels of flu, Covid-19 and RSV across most of the country. The latest data from the US Centers for Disease Control and Prevention notes that some measures of flu activity dipped in early January, but the single week of decrease is not a trend – and experts warn that more increases are likely to come.

In the latest update this week, and consistently through the season, the agency’s Center for Forecasting and Outbreak Analytics has suggested that this respiratory disease season will probably result in a similar number of hospitalizations as last season. And while current hospital capacity is considered stable overall, the CDC says that hospitals in some parts of the country have reported strains on their resources due, in part, to increases in respiratory illness.

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