Leading scientists worldwide continue advancing COVID-19 vaccine research, yet they emphasize caution. History shows no guarantee of success, particularly with this novel coronavirus's distinct characteristics compared to prior strains.
The University of Oxford's COVID-19 vaccine candidate has garnered attention after advancing to human clinical trials. Project leaders suggest it could reach the market by September 2020 if trials succeed.
Despite this optimism, experts urge caution. In a The Guardian article dated May 22, 2020, Jonathan Van-Tam, England's deputy chief medical officer since 2017, warned: "We can't be sure we'll get a vaccine."
Van-Tam highlights precedents like HIV, isolated over 30 years ago without a vaccine, and dengue, discovered in 1943 but only vaccinated in 2019. Even the fastest vaccine—against mumps—took four years.
Prior outbreaks like SARS (2003) and MERS (2012) advanced coronavirus vaccine knowledge, aiding current efforts. However, a key concern is that natural infection may not confer long-lasting immunity.
Evidence suggests immune responses fade quickly, with low antibody levels risking rapid reinfection. This raises doubts about vaccine durability—if protection lasts only a year, society may need to coexist with COVID-19 for years.
Viral genetic stability is crucial. Seasonal flu mutates swiftly, requiring annual new vaccine formulations; HIV's rapid evolution explains its vaccine elusiveness.
COVID-19 appears stable but, like all viruses, mutates over time. Some changes target spike proteins central to vaccine design, potentially rendering vaccine-induced antibodies ineffective by preventing viral binding and disease prevention.
