A recent study published in the Lancet has found that contraction of the novel coronavirus does not guarantee lifelong immunity for unvaccinated individuals and that the virus may return within a few months. Researchers from Yale University and the University of North Carolina concluded that unvaccinated individuals should expect to contract COVID-19 every 16 to 17 months.
As COVID-19 remains a relatively new virus, questions about the duration of immunity provided by previous infection persist. However, similar viruses offer some answers according to the study. Led by Jeffrey Townsend, a professor of biostatistics at Yale, researchers examined reinfection rates among the unvaccinated and determined that recovery from the virus does not provide lifelong protection.
The study analyzed post-infection data from six coronaviruses similar to the current strain, dating back to 1948. Using this data, the researchers estimated the average time until reinfection for unvaccinated individuals to be approximately 16 months. Townsend stated in a university press release, "Reinfection could occur within three months or less." Therefore, it is recommended that those who have previously been infected get vaccinated, as past infection may offer very little long-term protection against subsequent infections.
The study confirmed that some individuals may be reinfected within months, while for others, it could take years. The study's supervisors concluded that the findings may be valuable for public health policymakers, emphasizing that urgent measures will be crucial in reducing virus-related fatalities.
According to the Centers for Disease Control and Prevention (CDC), 57.2% of the U.S. population has been fully vaccinated, while 66.2% have received at least one dose of the vaccine. It is noteworthy that COVID-19 has resulted in at least 4,926,579 deaths globally since the World Health Organization reported the emergence of the disease in China at the end of December 2019.
