Viral diseases, including avian influenza (AI) and Newcastle disease (ND), are an important cause of morbidity and mortality in poultry, resulting in significant economic losses. Despite the availability of commercial vaccines for the major viral diseases of poultry, these diseases continue to pose a significant risk to global food security. There are multiple factors for this: vaccine costs may be prohibitive, cold chain storage for attenuated live-virus vaccines may not be achievable, and commercial vaccines may protect poorly against local emerging strains. The development of transient gene expression systems in plants provides a versatile and robust tool to generate a high yield of recombinant proteins with superior speed while managing to achieve cost-efficient production. Plant-derived vaccines offer good stability and safety these include both subunit and virus-like particle (VLP) vaccines. VLPs offer potential benefits compared to currently available traditional vaccines, including significant reductions in virus shedding and the ability to differentiate between infected and vaccinated birds (DIVA). This review discusses the current state of plant-based vaccines for prevention of the AI and ND in poultry, challenges in their development, and potential for expanding their use in low- and middle-income countries.

Background Hepatitis B infection seriously threatens global public health, especially in developing nations. Despite several investigations on HBV incidence, the national pooled prevalence remains unknown, particularly in populations at-risk at whom interventions should be primarily aimed. Methods A comprehensive literature search of the following databases: Medline [PubMed], Scopus, Google Scholar, and Web of Science was conducted following the PRISMA guidelines. I-squared and Cochran's Q were used to measure the heterogeneity between the studies. Publications that matched the following were included: Primary studies published in Egypt from 2000 to 2022 reported HBV prevalence based on HBsAg. We excluded any studies that were not performed on Egyptians or that were performed on patients suspected of acute viral hepatitis or studies focusing on occult hepatitis or vaccination evaluation studies, or national surveys. Results The systematic review included 68 eligible studies reporting a total of 82 incidences of HBV infection based on hepatitis B surface antigen with a total sample size of 862,037. The pooled national prevalence among studies was estimated to be 3.67% [95% CI; 3: 4.39]. Children under 20 with a history of HBV vaccination during infancy had the lowest prevalence of 0.69%. The pooled prevalence of HBV infection among pregnant women, blood donors, and healthcare workers was 2.95%, 1.8%, and 1.1%, respectively. While patients with hemolytic anemia and hemodialysis patients, patients with malignancies, HCC patients, and chronic liver disease patients had the highest prevalences at 6.34%, 25.5%, 18.6%, and 34%, respectively. Studies reporting HBV prevalence in urban settings compared to rural settings revealed a similar HBV prevalence of 2.43% and 2.15%, respectively. Studies comparing HBV prevalence in males and females revealed a higher prevalence among males (3.75%) than females (2.2%). Conclusion In Egypt, hepatitis B infection is a significant public health issue. The blocking of mother-to-infant hepatitis B transmission, the scaling up of the scope of the existing vaccination program, and implementing new strategies, including screen-and-treat, may reduce the prevalence of the disease.