"The coronavirus has become more adept at reinfecting people. Already, those infected with the first Omicron variant are reporting second infections with the newer versions of the variant — BA.2 or BA2.12.1 in the United States, or BA.4 and BA.5 in South Africa.
"Those people may go on to have third or fourth infections, even within this year, researchers said in interviews."
"Earlier in the pandemic, experts thought that immunity from vaccination or previous infection would forestall most reinfections.
"The Omicron variant dashed those hopes. Unlike previous variants, Omicron and its many descendants seem to have evolved to partially dodge immunity. That leaves everyone — even those who have been vaccinated multiple times — vulnerable to multiple infections."