Virus-like particles (VLPs) are a versatile, safe, and highly immunogenic vaccine platform. Recently, there are developmental vaccines targeting SARS-CoV-2, the causative agent of COVID-19. The COVID-19 pandemic affected humanity worldwide, bringing out incomputable human and financial losses. The race for better, more efficacious vaccines is happening almost simultaneously as the virus increasingly produces variants of concern (VOCs). The VOCs Alpha, Beta, Gamma, and Delta share common mutations mainly in the spike receptor-binding domain (RBD), demonstrating convergent evolution, associated with increased transmissibility and immune evasion. Thus, the identification and understanding of these mutations is crucial for the production of new, optimized vaccines. The use of a very flexible vaccine platform in COVID-19 vaccine development is an important feature that cannot be ignored. Incorporating the spike protein and its variations into VLP vaccines is a desirable strategy as the morphology and size of VLPs allows for better presentation of several different antigens. Furthermore, VLPs elicit robust humoral and cellular immune responses, which are safe, and have been studied not only against SARS-CoV-2 but against other coronaviruses as well. Here, we describe the recent advances and improvements in vaccine development using VLP technology.

Neglected Tropical Diseases (NTDs) are a group of diseases that are highly prevalent in tropical and subtropical regions, and closely associated with poverty and marginalized populations. Infectious diseases affect over 1.6 billion people annually, and vaccines are the best prophylactic tool against them. Along with NTDs, emerging and reemerging infectious diseases also threaten global public health, as they can unpredictably result in pandemics. The recent advances in vaccinology allowed the development and licensing of new vaccine platforms that can target and prevent these diseases. In this work, we discuss the advances in vaccinology and some of the difficulties found in the vaccine development pipeline for selected NTDs and emerging and reemerging infectious diseases, including HIV, Dengue, Ebola, Chagas disease, malaria, leishmaniasis, zika, and chikungunya.

The COVID-19 vaccinations have played a significant role in controlling the pandemic. To elucidate their impact on the immune system, a COVID-19 vaccination atlas was developed using an integrative systems vaccinology approach. The atlas includes 562 samples from 245 participants, including both healthy individuals and those infected with or without prior vaccination, and covers the administration of five vaccines in different regimens. Key findings include the identification of distinct immune markers that differentiate between vaccine types and infection statuses. We observed that mRNA vaccines induced transient but strong immune responses after booster doses, whereas viral vector vaccines showed sustained immune activation with infection, partially resembling the immune profile exhibited during infection. Heterologous vaccination regimens demonstrated enhanced immune diversification compared to homologous regimens. Finally, we described the immunological landscape of COVID-19 vaccines and vaccines against other pathogens, at the gene-level and in cell population dynamics.

The COVID-19 vaccinations have played a significant role in controlling the pandemic. To elucidate their impact on the immune system, a COVID-19 vaccination atlas was developed through an integrative systems vaccinology approach. The atlas includes both healthy individuals and those infected with or without prior vaccination, and covers the administration of five vaccines in different regimens: Covilo®, Zifivax®, Vaxzebria® or Covishield®, Spikevax®, and Comirnaty®. Critical markers were identified to discriminate the different types of vaccines and infection, in which infection was associated with GATA3, ZNF3, KMT2A, ASXL1, SP100, and GZMM, and vaccine types were marked by ITGAM, ACTG1, LGALS3, and STAT5B. Additionally, the immunological signatures of heterologous vaccination and infection were described, and it was also shown how a full vaccination regimen markedly limited the shift of immune responses during natural infection, thereby constraining disease progression. Finally, the common transcripts shared across COVID-19 vaccines and vaccines against other pathogens were described.

Dengue virus (DENV) and Zika virus (ZIKV) are public health threats, causing substantial morbidity and mortality worldwide. The co‐circulation of DENV and ZIKV complicates prevention and control efforts, highlighting the importance of studying cross‐reactive antibodies, vaccines, and immune modulators. This study explores the cross‐reactivity and neutralizing capacity of antibodies against DENV elicited by immunization with a ZIKV protein extract. Female isogenic BALB/c mice were immunized with ZIKV protein extract derived from C6/36 cell cultures. Splenic B lymphocytes from immunized mice were fused with myeloma cells using polyethylene glycol (PEG) to generate hybridomas. The resulting antibodies were assessed using ELISA and plaque reduction neutralization tests (PRNT) against ZIKV and DENV including their structural and nonstructural proteins. Our findings showed that immunization induced a diverse antibody response, including antibodies recognizing epitopes unique to ZIKV as well as epitopes shared with DENV. Notably, neutralizing antibodies targeting conserved epitopes, particularly those shared with DENV‐1, were also identified against other DENV serotypes. These results suggest the presence of cross‐reactive neutralizing antibody responses between ZIKV and DENV, potentially exhibiting serotype‐specific reactivity. Collectively, this study provides experimental evidence of flavivirus cross‐reactivity and contributes to a more refined understanding of humoral responses in settings where these viruses co‐circulate.

The COVID-19 vaccinations have played a significant role in controlling the pandemic. To elucidate their impact on the immune system, a COVID-19 vaccination atlas was developed through an integrative systems vaccinology approach. The atlas includes both healthy individuals and those infected with or without prior vaccination, and covers the administration of five vaccines in different regimens: Covilo®, Zifivax®, Vaxzebria® or Covishield®, Spikevax®, and Comirnaty®. Critical markers were identified to discriminate the different types of vaccines and infection, in which infection was associated with GATA3, ZNF3, KMT2A, ASXL1, SP100, and GZMM, and vaccine types were marked by ITGAM, ACTG1, LGALS3, and STAT5B. Additionally, the immunological signatures of heterologous vaccination and infection were described, and it was also shown how a full vaccination regimen markedly limited the shift of immune responses during natural infection, thereby constraining disease progression. Finally, the common transcripts shared across COVID-19 vaccines and vaccines against other pathogens were described.