Study of immunogenicity and efficacy against Omicron BA.5 of recombinant protein-based COVID-19 vaccine delivered by intramuscular and mucosal routes in nonhuman primates.

BACKGROUND: With SARS-CoV-2 continuing to evolve, there is a need to adapt COVID-19 vaccines to enhance mucosal immunity and better address immune-evasive variants. This pilot study was performed in mice and rhesus macaques to compare Advax-adjuvanted monovalent and bivalent recombinant spike protein vaccines, including when delivered via a combination of intramuscular (IM) and intrapulmonary (IPM) or oral routes. METHODS: Mice were first used to compare the immunogenicity of monovalent and bivalent vaccines containing a variety of spike protein variants. Then, rhesus macaques (n = 23) were divided into 5 groups to receive COVID-19 vaccines via different routes. Clinical signs, local vaccination site reactions, body weight, food consumption, serum, alveolar lavage, nasal and oral antibody levels, and nasal and alveolar lavage virus loads were assessed in response to a heterologous Omicron BA.5 virus challenge. RESULTS: The Wuhan + Mu bivalent vaccine gave the most broadly cross-neutralizing antibody responses. Robust serum neutralizing antibodies against Wuhan, Delta and Lambda variants were obtained, but BA.5 neutralizing antibodies were not detectable pre-challenge. Overall, the IM x3 and the IM x2 plus oral x2 vaccines delivered the best protection, with reduced lung virus load versus unimmunized controls across Days 2, 4 and 7. CONCLUSIONS: Advax-adjuvanted monovalent or bivalent recombinant spike protein vaccines given via parenteral and/or mucosal routes protected against a heterologous BA.5 challenge, despite absent serum BA.5 neutralizing antibody, pre-challenge. The possibility of using an oral Advax-adjuvanted protein booster to provide broad protection against newer SARS-CoV-2 variants warrants further investigation.

In vitro activity of cysteamine against SARS-CoV-2 variants.

Global COVID-19 pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Continuous emergence of new variants and their rapid spread are jeopardizing vaccine countermeasures to a significant extent. While currently available vaccines are effective at preventing illness associated with SARS-CoV-2 infection, these have been shown to be less effective at preventing breakthrough infection and transmission from a vaccinated individual to others. Here we demonstrate broad antiviral activity of cysteamine HCl in vitro against major emergent infectious variants of SARS-CoV-2 in a highly permissible Vero cell line. Cysteamine HCl inhibited infection of wild type, alpha, beta, gamma, delta, lambda, and omicron variants effectively. Cysteamine is a very well-tolerated US FDA-approved drug used chronically as a topical ophthalmic solution to treat ocular cystinosis in patients who receive it hourly or QID lifelong at concentrations 6 times higher than that required to inhibit SARS CoV-2 in tissue culture. Application of cysteamine as a topical nasal treatment can potentially1) mitigate existing infection 2) prevent infection in exposed individuals, and 3) limit the contagion in vulnerable populations.

Homegarden diversity and food security in southern Mexico.

Home gardens are recognised in the literature for their contribution to food security, yet the process by which agrobiodiversity and household characteristics mediate this relationship is less well understood. This paper contributes to fill this research gap by drawing on a multi-site case study in the Yucatán region in Mexico. By applying regression analysis, the significance of the association between home garden diversity and food security is confirmed. Plant diversity is found to have a positive association with food consumption scores and the frequency of vegetable intakes. The number of animals used for food purposes is also found to have positive and significant associations with food consumption scores and frequency of meat intakes. However, the dimension and the significance of these positive associations were found to vary among communities and quantiles of the distribution of food security measures. In the households studied, younger individuals and better-educated people, males and Spanish speakers were more likely to engage in jobs in urban areas. Engagement in urban jobs was found to involve complementarities with the overall plant diversity of home gardens, but also trade-offs with the diversity of vegetables and other herbs used for food purposes and with the abundance of animals raised for food purposes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12571-021-01148-w.