Advisers to the World Health Organization recommended on Monday that people with weakened immune systems who have been fully vaccinated get booster shots of new coronavirus vaccine.
People in the US and some European nations who are immunocompromised can already get boosters. The advisers weighed in, saying such individuals are "less likely to respond adequately to vaccination."
Experts said even people in the group who are fully vaccinated with shots from Pfizer-BioNTech, Moderna, or AstraZeneca are at risk of breakthrough infections. So, they could still suffer from a severe case.
The advisers also suggested that people aged 60 and older who received the Chinese vaccines Sinopharm or Sinovac get another shot. They said studies involving people in that age group in Latin America show those vaccines perform less well over time.
WHO leaders have accused wealthy nations of hoarding vaccines. They said, as of last week, less than 5 percent of people in Africa had been fully vaccinated.