Patients who recover from coronavirus infections may lose their immunity to reinfection within months, according to research released yesterday that experts said could have a "significant" influence on how governments manage the pandemic.
In the first study of its kind, a team led by researchers from King's College London examined the levels of antibodies in more than 90 confirmed virus patients and how they changed over time.
Blood tests showed even individuals with only mild COVID-19 symptoms mounted some immune response to the virus. Of the study group, 60 percent showed a "potent" viral response in the first few weeks after infection.
However, after three months only 16.7 percent had maintained high levels of COVID-19-neutralising antibodies, and after 90 days several patients had no detectable antibodies in their bloodstream.
The research suggests immunity cannot be taken for granted and may not last more than a few months, as is true with other viruses such as influenza.
Experts said the findings may change how governments plan for the next phase of the pandemic, including how they fund and organise vaccine research and development.
Meanwhile, according to a United Nations report published yesterday, nearly one in nine people in the world are going hungry.
Economic slowdowns and climate-related shocks are pushing more people into hunger, while nutritious foods remain too expensive for many, contributing not only to undernourishment, but to growing rates of obesity in all.
Nearly 690 million people, or 8.9 percent of people around the globe, are hungry, the UN found. That number rose by 10 million people in just one year to 2019, found the study, which said eradicating hunger by 2030 - a goal set five years ago - will be impossible if trends continue.
Five United Nations agencies co-authored the report: the Food and Agriculture Organization (FAO), the International Fund for Agricultural Development (IFAD), the United Nations Children's Fund (UNICEF), the World Food Programme (WFP) and the World Health Organization (WHO).