Reduced Risk of Re-infection: New Study Suggests Covid-19 Antibody Positivity Offers 10-Fold Protection

Strategic Insights -

Researchers from the National Cancer Institute and partnering companies have found that individuals who test positive for Covid-19 antibodies have a significantly lower risk of re-infection with SARS-CoV-2. According to the study published in JAMA Internal Medicine, people who tested positive for Covid-19 antibodies were at a decreased risk of coronavirus infection compared with those who tested negative for antibodies. The study suggests that being antibody-positive after natural infection is associated with partial protection against a new infection, although more research is needed to determine a causal relationship and the duration of this protection.

Key Takeaways:

  • A study published in JAMA Internal Medicine found that individuals who tested positive for Covid-19 antibodies had a 10-fold reduction in risk of re-infection compared to those who tested negative.
  • The study analyzed data from over 3.2 million people in the United States who completed a Covid-19 antibody test between January and August 2021.
  • Among those tested, 11.6% tested positive for Covid-19 antibodies, while 88.3% tested negative.
  • The study found that only 0.3% of those who tested positive for Covid-19 antibodies ended up testing positive for coronavirus infection later, beyond 90 days, compared to 3% of those with negative Covid-19 antibody test results.
  • Dr. Douglas Lowy, principal deputy director of the National Cancer Institute, emphasized that people who have recovered from Covid-19 should still get vaccinated when it is their turn.
  • The study suggests that there is an association between positive Covid-19 antibody test results and a lower risk of infection some 90 days later, but more research is needed to determine a causal relationship and the duration of protection.

Statistics:

  • 11.6% of over 3.2 million people tested positive for Covid-19 antibodies between January and August 2021.
  • 88.3% of over 3.2 million people tested negative for Covid-19 antibodies between January and August 2021.
  • 0.3% of those who tested positive for Covid-19 antibodies later tested positive for coronavirus infection beyond 90 days.
  • 3% of those with negative Covid-19 antibody test results later tested positive for coronavirus infection beyond 90 days.

Sources:

  • Howard, J. (2023) New evidence suggests Covid-19 antibodies lower risk of re-infection. CNN.
  • JAMA Internal Medicine. (2023) Association Between Covid-19 Antibody Positivity and Lower Risk of Re-infection.
  • Lowy, D. (2023) Principal Deputy Director of the National Cancer Institute. Interview with CNN.