Inactivated SARS-CoV Vaccine Prepared from Whole Virus Induces a High Level of Neutralizing Antibodies in BALB/c Mice

Abstract

We tested the ability of inactivated SARS-CoV vaccine to induce neutralizing antibodies in BALB/c mice. The inactivated vaccine was prepared by SARS-CoV virus propagation in Vero cells, with subsequent beta-propiolactone inactivation and Sepharose 4FF column chromatography purification. One hundred forty BALB/c female mice were divided into seven groups of 20 mice each. Of the seven groups, three groups were inoculated with 0.1, 1, and 3 microg of the vaccine without adjuvant while three other groups were inoculated at the same three dosages of vaccine with aluminum hydroxide as adjuvant, respectively. The remaining group was set up as a blank control. Each mouse was inoculated twice at an interval of 3 weeks. One week after the second immunization, mice sera were collected to detect serum neutralizing antibodies. An assay for determining neutralizing antibody titers was developed. The results can be summarized as follows: (1) higher dosages of vaccine induced higher levels of neutralizing antibody titer; (2) the level of neutralizing antibodies induced by the inoculation with aluminum hydroxide adjuvant was slightly higher than that without adjuvant, but the difference was not statistically significant.

Intranasal Vaccination of Recombinant Adeno-Associated Virus Encoding Receptor-Binding Domain of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) Spike Protein Induces Strong Mucosal Immune Responses and Provides Long-Term Protection against SARS-CoV Infection

“…Several vaccine strategies proposed for prevention of SARS include inactivated virus-based vaccines (15), DNA-based vaccines (16), recombinant subunit vaccines (17), and viral vector-based vaccines (18). These vaccine candidates are able to induce protective immune responses against SARS-CoV, including NA and T cell immune responses (14, 19 -21).…”

Elicitation of Immunity in Mice After Immunization with the S2 Subunit of the Severe Acute Respiratory Syndrome Coronavirus

“…For protein vaccination, 50 g of recombinant protein was formulated with 50 l of Incomplete Freund's Adjuvant (IFA, Sigma-Aldrich, St. Louis, MO) in a total volume of 0.1 ml per dose. Inactivated vaccine was prepared as previously described (Tang et al, 2004). Briefly, Vero cells were infected with the SARS-CoV and incubated in a serum-free medium at 37°C for 36 h. When the infective titer reached 10 7 TCID 50 , the cells were lysed by freezing and thawing at Ϫ20°C, followed by centrifugation at 6000 rpm for 20 min.…”

“…Neutralization of SARS-CoV infection was assessed as previously described (Tang et al, 2004). Briefly, the sera of mice were collected 1 week after the second immunization and doubly diluted with PBS.…”

Newcastle disease virus, a host range-restricted virus, as a vaccine vector for intranasal immunization against emerging pathogens

“…Inactivated whole-virus preparations of SARS-CoV have been shown to induce protective immunity in small-animal models (2)(3)(4)(5) and primates (6,7). However, large-scale growth of a highly pathogenic agent introduces the risk of laboratory infection, which indeed has occurred (8).…”