Thread by @BenjaCurrents

SARS vaccines: where are we?
"Data regarding the correlates of protection, animal models and the available evidence regarding potential vaccine ENHANCEMENT of SARS disease are discussed"

Inactivated virus vaccines
"However, despite high neutralizing antibody titers, protection was incomplete for all vaccine preparations and administration routes tested." 🤔@juancarlossaid

AdVs vectored SARS-CoV vaccines
"Interestingly, although the intramuscular route was more effective in inducing neutralizing SARS serum antibodies, the INTRANASAL route of administration induced IgA and was MORE EFFECTIVE in blocking SARS-CoV replication in nose and lung tissue"

"Ferrets are a good model for SARS-CoV because they support replication in the upper and lower respiratory tracts, develop clinical disease, shed virus from the upper airway and develop severe lung pathology "

Vaccine enhancement of disease
"The greatest fear among vaccinologists is the creation of a vaccine that is not only ineffective, but which exacerbates disease. Unfortunately, CoV vaccines have a history of enhancing disease, notably with feline CoVs"

"Other groups have also shown that administration of anti-S antibody does not enhance disease upon SARS-CoV challenge in mice or ferrets , again suggesting that antibody is not enhancing disease in SARS-CoV infection."

"In our ferret vaccine trials using S and N proteins, we noted a delayed histopathology in vaccinated groups, but no increase in pathology compared to unvaccinated groups " @luigi_warren @Wezuwezu

"In the vast majority of studies, immunogenicity has been elicited without any negative impact on health after challenge with the virulent pathogen."

"However, we have shown that, while inactivated SARS with alum vaccine induced 15-fold higher serum-neutralizing antibody titers than the other vaccines (Ad-vectored), this vaccine did not universally protect ferrets better from SARS-CoV challenge" @commieleejones @jjcouey

"The ability of an antibody to neutralize virus infection is the easiest activity to measure, but it is not the only important function of antibody in antiviral defense." @eugyppius1 @drcraigwax

"Intranasal administration increases protection, despite greatly reduced serum antibody responses. These data underscore the importance of mucosal immunity." @gerdosi @Ducky68257909

"The data indicate that the most efficacious vaccine strategy might be a heterologous combination of intranasal and systemic vaccination, since each delivers different aspects of protection. Given the incomplete protection of current vaccines, it seems unwise to discount T-cell"

July 2009: "SARS vaccines: where are we?"
tandfonline.com/doi/full/10.15…