Large-scale inequities in the distribution of COVID-19 vaccines to low- and middle-income countries will ensure that the virus is here to stay for many years. Even if the SARS-CoV-2 vaccine coverage is sufficient to eventually eradicate the current pandemic, issues of existing and future variants and new coronaviruses remain.
While the current vaccines appear to have some efficacy against variants of SARS-CoV-2, protection against new mutations is not guaranteed, and breakthrough infections still may occur. The magnitude of the COVID-19 pandemic requires a rapid response to develop broad-spectrum agents to combat multiple strains of coronaviruses.
The Population Council is developing a self-administered, on-demand, low-cost nasal spray containing Griffithsin and carrageenan that has the potential to neutralize the coronavirus in the upper respiratory tract—the virus’s point of entry—by binding to the spike protein that gives the coronavirus its distinctive morphology.
Such a product could prevent the virus from establishing the infection; migrating to the lower respiratory tract, thereby preventing the sequelae that SARS-CoV-2 can cause; or spreading to other susceptible hosts.
Griffithsin has demonstrated effectiveness against a broad range of human and animal coronaviruses, providing strong evidence that it may be effective against future variants and new coronaviruses, especially if combined with a potent antimicrobial such as carrageenan. In laboratory studies, Griffithsin and carrageenan are shown to have a powerful synergistic effect in neutralizing the SARS-CoV-2 virus.
A self-administered nasal spray could address some aspects of vaccine hesitancy and user preference and ameliorate distribution challenges in low-resource settings. An on-demand nasal spray could also be provided to frontline workers and others who interact with high-risk populations (and therefore are especially vulnerable to breakthrough infections). Finally, it could be a crucial stopgap measure to buy time while existing vaccines are evaluated against new mutations and new coronaviruses.
The Population Council is currently seeking funding to evaluate the Griffithsin-Carrageenan formulation in vivo to test the efficacy of this formulation against SARS-CoV-2 and select the lead formulation. The proposed nasal spray product may prevent the SARS-CoV-2 (and other coronavirus) infection, decrease transmission, and/or reduce the severity of the disease.