1st and 2nd-generation COVID-19 Vaccines with Dr. Deborah Fuller

In this video interview, we discuss the strengths and limitations of COVID-19 vaccine candidates with Dr. Deborah Fuller, Professor of Microbiology at University of Washington. Her lab, which studies influenza, HIV, and Zika virus, is currently focused on immunity against COVID-19 and the development of novel vaccination strategies against SARS-CoV-2. Her lab’s work has resulted in over a dozen patents and two startup biotech companies. 

Key Points

• RNA vaccines are safe and immunogenic but are highly dependent on the “cold chain” compared to other types of vaccines  
• DNA vaccines are generally less immunogenic than RNA vaccines in terms of antibody responses, but could be stored at room temperature and may be more effective in the induction of T-cell responses 
• Adenovirus vaccines are immunogenic and easy to manufacture; however, they are less suitable for repeat immunization (e.g. booster shots) due to the development of anti-adenovirus vector immunity 
• Considerations for vaccine design include:
  • Minimization of antibody-dependent enhancement of type 2 helper T cell response
  • Maximization of neutralizing antibody and type 1 helper T cell response to avoid vaccine-enhanced respiratory disease 
• Next-generation vaccines are being designed to fix potential shortcomings of 1st-generation vaccines in regards to cost of scale-up, needle-free delivery, single-shot efficacy, long-term immunity & immunity in special populations (e.g. elderly adults), as well as minimization of dependence on the “cold chain” 

Time Stamps

• DNA and RNA vaccines for COVID-19 (00:41)
• Storage requirements of DNA vaccines (02:21)
• Storage requirements of RNA vaccines (02:49)
• Strengths of RNA vaccines (03:14)
• Moderna vs. Pfizer’s RNA vaccine (06:46)
• Strengths and weaknesses of adenovirus vaccines (09:59)
• CanSino vaccine (11:27)
• Immunogenicity vs. reactogenicity of vaccines (14:20)
• Antibody-dependent enhancement (16:16)
• Type 2 helper T cell response (17:15)
• Role of T cell response in immunity (21:36)
• Immunological memory and long-term protection against infection (23:54)
• Vaccines and long-term protection against infection (27:44)
• Next-generation vaccines (28:43)
• Next-generation vaccines and the “Cold Chain” (31:03)
• Clinical development of UW’s self-replicating RNA vaccine (32:34)