Following new data from Imperial College London (ICL) suggesting that antibody levels against SARS-CoV-2 wane over time; Michael Breen, Director of Infectious Diseases and Ophthalmology at GlobalData offers his view.
“One of the most salient implications for the new data by ICL, which suggests that antibody levels against SARS-CoV-2 drop by more than 25 per cent in as little as several months, is that protection against reinfection may decrease as antibody levels drop. This rains on the parade of the often-touted ‘herd immunity’ method and increases the potential for multiple waves of COVID-19 outbreaks. However, these data do not necessarily point to such dire outcomes.
“Indeed, decreasing levels of antibodies is not ideal – with waning protection from natural infection also suggesting that vaccines against this pathogen might not confer long-lasting protection and require seasonal vaccination for control – our understanding of the natural course of this disease is still nascent. As we learn more about infection and disease management, we will also be better equipped to combat future outbreaks.
“We should keep in mind that lower levels of antibodies do not absolutely mean increased risk of reinfection. While important in combating infection, antibodies are only one part of a range of host defense systems. However, with coronavirus infections, we tend to see the opportunity for reinfection on a yearly basis, thus these other mechanisms may not be able to defend against this novel coronavirus.”
“Also, importantly, levels of antibodies decreased more in the elderly than in healthcare workers, possibly due to healthcare workers regularly being exposed to SARS-CoV-2. Therefore, we know that we must more carefully monitor those in this age group, and possibly vaccinate this group more frequently than others due to their decreased ability to maintain protective levels of antibodies.”