Recombination of the genome occurs within actively infected cells. Following the onset of viral DNA replication, an intermediate set of genes codes for transcription factors of late gene expression. The products of the later genes include transcription factors necessary for transcribing the early genes for new virions, as well as viral RNA polymerase and other essential enzymes for new viral particles. These proteins are then packaged into new infectious virions capable of infecting other cells. Research
Two live samples of Variola major remain, one in the United States at the CDC in Atlanta, and one at the Vector Institute in Koltsovo, Russia. Research with the remaining virus samples is tightly controlled, and each research proposal must be approved by the WHO and the World Health Assembly (WHA). Most research on poxviruses is performed using the closely related Vaccinia virus as a model organism. Vaccinia virus, which is used to vaccinate for smallpox, is also under research as a viral vector for vaccines for unrelated diseases.The genome of Variola major was first sequenced in its entirety in the 1990s. The complete coding sequence is publicly available online.The current reference sequence for Variola major was sequenced from a strain that circulated in India in 1967. In addition, there are sequences for samples of other strains that were collected during the WHO eradication campaign. A genome browser for a complete database of annotated sequences of Variola and other poxviruses is publicly available through the Viral Bioinformatics Resource Center. Genetic engineering
The WHO currently bans genetic engineering of the smallpox virus.
Esomeprazole reduces the production of digestive acids, thus reducing their effect on the esophagus. Duodenal ulcers
Esomeprazole is combined with the antibiotics clarithromycin and amoxicillin (or metronidazole instead of amoxicillin in penicillin-hypersensitive patients) in a 10-day eradication triple therapy for Helicobacter pylori. Infection by H. pylori is a causative factor in the majority of peptic and duodenal ulcers. Efficacy
A 2006 meta analysis concluded that compared to other proton pump inhibitors, esomeprazole confers a modest overall benefit in esophageal healing and symptom relief. When broken down by disease severity, the benefit of esomeprazole relative to other proton pump inhibitors was negligible in people with mild disease (number needed to treat 50), but appeared more in those with severe disease (number needed to treat 8). A second meta analysis also found increases in erosive esophageal healing (>95% healing rate) when compared to standardized doses in broadly selected patient populations. A 2017 study found esomeprazole to be among a number of effective doses of PPIs. Adverse effects
Common side effects include headache, diarrhea, nausea, flatulence, decreased appetite, constipation, dry mouth, and abdominal pain. More severe side effects are severe allergic reactions, chest pain, dark urine, fast heartbeat, fever, paresthesia, persistent sore throat, severe stomach pain, unusual bruising or bleeding, unusual tiredness, and yellowing of the eyes or skin.Proton pump inhibitors may be associated with a greater risk of hip fractures and Clostridium difficile-associated diarrhoea.