In a recent interview, infectious disease epidemiologist Tara Smith shared her expertise on the ongoing COVID-19 pandemic. As an expert in zoonotic diseases, which are transmitted between animals and humans, Smith provided valuable insights into the current situation. She addressed various questions about COVID-19, including the potential for immunity from cold coronaviruses, the impact on the neurological system, the challenges in developing a vaccine, the need for ongoing social distancing, and the potential for long-term immunity. Smith also discussed the possibility of chronic infection and the potential lessons we can learn from bats’ immune systems. This article provides a summary of her responses to these pressing questions.
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Smith explained that there is limited cross-protective immunity between different coronavirus species. Even when immunity does develop, it tends to wane relatively quickly. Studies have shown that the human coronaviruses that cause the common cold also elicit short-term immunity. Therefore, recent exposure to a common cold coronavirus does not necessarily provide protection or prophylaxis against COVID-19.
Can COVID-19 cause changes in hearing?
Smith noted that there is currently no evidence to suggest that COVID-19 affects the nerves of the auditory system. While the virus can enter through the olfactory (smell) nerves and affect the surrounding tissues, its impact on the auditory system is yet to be determined. Smith emphasized the need for further research in this area.
Why has it been challenging to develop a COVID-19 vaccine?
Smith explained that developing an effective and safe vaccine involves multiple factors. One of the challenges is the mutation rate of the virus. COVID-19 mutates less frequently than influenza, making it relatively stable. However, finding good antigens that generate a robust immune response without causing harm to the host is essential. Smith pointed out that previous attempts to develop vaccines for SARS and MERS coronaviruses were hindered by safety concerns, such as antibody-dependent enhancement, where the antibodies produced by the vaccine actually worsen the infection. Smith highlighted the need for careful selection of antigens and ongoing research efforts to develop a successful vaccine for COVID-19.
Smith acknowledged that social distancing has played a crucial role in slowing the spread of COVID-19. However, she emphasized the importance of transitioning from mitigation efforts to a containment strategy. This strategy involves widespread testing, isolation of infected individuals, contact tracing, and quarantine of exposed individuals. Smith mentioned that the lack of testing supplies and logistical challenges make it difficult to implement this strategy currently. She expressed hope that testing capacity would improve, allowing for a more effective containment approach to replace long-term social distancing measures.
How long will it take to develop herd immunity?
Smith explained that the percentage of the population that needs to be immune to achieve herd immunity depends on the virus’s transmissibility. With an estimated reproductive number (R0) of three for COVID-19, approximately 60 to 70 percent of the population would need to be immune to reach the herd immunity threshold. However, the duration of immunity and the level of protection against reinfection are still unknown. Smith highlighted the need for long-term studies to determine the duration and strength of immunity, as well as the potential for reinfection.
Smith addressed several other questions, including the possibility of COVID-19 becoming a chronic infection, the role of bats’ immune systems in handling viruses, and the evolution of viruses to become less pathogenic. She emphasized the need for ongoing research and cautioned against making definitive conclusions without robust scientific evidence. Smith’s expertise and insights provide valuable information for understanding and combating the COVID-19 pandemic.
