Large differences in COVID‐19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage were associated with low death rates in European countries. SARS‐CoV‐2 binds to its receptor, the angiotensin converting enzyme 2 (ACE2). As a result of SARS‐Cov‐2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT 1 R) axis associated with oxidative stress. This leads to insulin resistanceas well as lung and endothelial damage, two severe outcomes of COVID‐19. The nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2) is the most potent antioxidant in humans and can block the AT 1 R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are given: Kimchi in Korea, westernized foods and the slum paradox. It is proposed that fermented cabbage is a proof‐of‐concept of dietary manipulations that may enhance Nrf2‐associated antioxidant effects helpful in mitigating COVID‐19 severity.

Adjuvants may promote immune responses: by recruiting professional antigen-presenting cells (APCs) to the vaccination site, increasing the delivery of antigens to APCs, or by activating APCs to produce cytokines and by triggering T cell responses. Aluminium salts have been effective at promoting protective humoral immunity; however, they are not effective in generating cell-mediated immunity. A number of different approaches have been developed to potentiate immune response and they have been partially successful. Research has been conducted into vaccine delivery systems (VDS); enhancing cross-presentation by targeting antigens to (APCs). Antigen discovery has increased over the past decade, and consequently, it has accelerated vaccine development demanding a new generation of VDS that combines different types of adjuvants into specific formulations with greater activity. The new approaches offer a wide spectrum of opportunities in vaccine research with direct applications in the near future.

Coronaviruses (CoVs) are a collection of enveloped viruses with non-segmented, positive-sense single-stranded RNA genomes with distinctive crown-like spikes that protrude from the capsid of helical symmetry. 1 They have a remarkably long RNA genome and a particular replication strategy. In this complex family, several members attack different species causing several diseases that can end up in death. In November 2002, in China, a severe acute respiratory syndrome coronavirus (SARS-CoV) was identified. It promptly spread to other countries. There were around 8000 confirmed cases, and the mortality rate was 9.6%. 2 Then, another member of the family, Middle East respiratory syndrome coronavirus (MERS-CoV), appeared in Saudi Arabia in 2012 and later emerged in South Korea in 2015. The confirmed cases of MERS-CoV exceeded 2000, with a mortality rate of ∼35%. 2 In 2019, another member of the family was identified, SARS-CoV-2. 3 The number of infected people and the mortality rate still grow continuously. Infected elderly individuals with comorbidities exhibit the worst outcomes. There are now several vaccines against SARS-CoV-2 approved for emergency use by the regulatory offices of different countries.The coronavirus genome is formed by 2 UTR sites, 5′ and 3′, the replicase, the spike (Spike), the envelope E (Envelope), the M (Membrane), the N (Nucleocapsid) and

Metabolic syndrome (MetS) is a syndrome that involves at least three disorders dyslipidemia, insulin resistance, obesity and/or hypertension. MetS has been associated with several chronic diseases in the adulthood; however, in the recent years, the syndrome was redefined in children. Girls with early menarche and asthma, and children with MetS and asthma that reach adulthood appear to have higher risk to develop severe or difficult to control asthma and a higher probability to suffer cardiovascular diseases. It has been proposed that patients with MetS and endocrinological disorders should be considered a different entity in which pharmacologic treatment should be adjusted according to the individual. Recent patents on the field have addressed new issues on how endocrine control should be managed along with asthma therapeutics. In the near future, new approaches should decrease the high morbidity and mortality associated to these types of patients.

The scope of the article is to review the different approaches that have been used for HIV vaccines. The review is based on articles retrieved by PubMed and clinical trials from 1990 up to date. The article discusses virus complexity, protective and non-protective immune responses against the virus, and the most important approaches for HIV vaccine development.