Health and Science

Recovered Covid patients have been reinfected with new virus strains, WHO says

Key Points
  • Preliminary reports from South Africa suggest people with prior Covid infection could be reinfected with a new, more infectious variant of the virus, the World Health Organization said.
  • Initial findings also show Covid vaccines may be less effective in protecting against new strains of the virus, but vaccination may reduce the severity of infection, WHO said.
  • Vaccination may also decrease the spread of new Covid variants, according to WHO.
A lab technician uses a single channel pipette dropper to test material during Covid-19 polymerase chain reaction (PCR) test processing at a laboratory in the Dunkeld suburb of Johannesburg, South Africa, on Wednesday, Feb. 10, 2021.
Waldo Swiegers | Bloomberg | Getty Images

Preliminary reports from South Africa show people who have recovered from Covid-19 have been reinfected with a new, more contagious variant of the virus, World Health Organization officials said at a press briefing Friday.

The good news, however, is that the vaccines developed to guard against the virus appear to reduce the severity of illness in those who do develop Covid-19, even if it doesn't completely protect them from infection, said the WHO's chief scientist, Dr. Soumya Swaminathan.

Dr. Scott Gottlieb discusses the rise in variant Covid cases
Dr. Scott Gottlieb discusses the rise in variant Covid cases

"The [vaccine] trials that have been done so far in South Africa as well as in Brazil with different candidates have shown complete protection against severe disease and hospitalization and death. There hasn't been a single case reported in any of the trials," she said.

Vaccination may also decrease the spread of new Covid variants, according to the WHO.

"There are reports now that if you have the vaccine and you get infected, the viral load is much lower. So the chances of infecting others may be lower," said Swaminathan.

Prior Covid infection produces antibodies and cell mediated immunity that are thought to prevent reinfection, scientists have found. Vaccination also helps individuals build protection against the virus.

But researchers continue to study the extent to which prior infection and vaccination protect against the new, more infectious variants of the coronavirus.

Increased vaccination efforts alone are likely insufficient in managing the spread of the coronavirus strain originating in the U.K., Dr. Scott Gottlieb, former commissioner of the Food and Drug Administration, told CNBC on Thursday. Gottlieb said a combination of incoming warmer weather and ramped up vaccinations could help contain the variant.

Swaminathan at the WHO briefing Friday stressed the importance of vaccinated people continuing to take precautions such as mask wearing, hand washing and social distancing to control the spread of the virus.