Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix® and RotaTeq® vaccine strains in stool samples
Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix® and RotaTeq® are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix® and RotaTeq® vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix® and RotaTeq® vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix® (NSP2, VP4) and RotaTeq® (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix® NSP2 and VP4 qRT-PCR assays exhibited 92–100% sensitivity, 99–100% specificity, 94–105% efficiency, and a limit of detection of 2–3 copies per reaction. RotaTeq® VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94–100% specificity, 91–102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix® and RotaTeq® vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE.
Public Health Officials Know: Recently Vaccinated Individuals Spread Disease
Washington, D.C., March 3, 2015 (GLOBE NEWSWIRE) — Physicians and public health officials know that recently vaccinated individuals can spread disease and that contact with the immunocompromised can be especially dangerous. For example, the Johns Hopkins Patient Guide warns the immunocompromised to “Avoid contact with children who are recently vaccinated,” and to “Tell friends and family who are sick, or have recently had a live vaccine (such as chicken pox, measles, rubella, intranasal influenza, polio or smallpox) not to visit.”1
A statement on the website of St. Jude’s Hospital warns parents not to allow people to visit children undergoing cancer treatment if they have received oral polio or smallpox vaccines within four weeks, have received the nasal flu vaccine within one week, or have rashes after receiving the chickenpox vaccine or MMR (measles, mumps, rubella) vaccine.2
“The public health community is blaming unvaccinated children for the outbreak of measles at Disneyland, but the illnesses could just as easily have occurred due to contact with a recently vaccinated individual,” says Sally Fallon Morell, president of the Weston A. Price Foundation. The Foundation promotes a healthy diet, non-toxic lifestyle and freedom of medical choice for parents and their children. “Evidence indicates that recently vaccinated individuals should be quarantined in order to protect the public.”
Scientific evidence demonstrates that individuals vaccinated with live virus vaccines such as MMR (measles, mumps and rubella), rotavirus, chicken pox, shingles and influenza can shed the virus for many weeks or months afterwards and infect the vaccinated and unvaccinated alike.
“Official data have shown that the large-scale vaccinations undertaken in the US have failed to obtain any significant improvement of the diseases against which they were supposed to provide protection.” Dr A. Sabin, developer of the Oral Polio vaccine
Dr A. Sabin, developer of the Oral Polio vaccine (lecture to Italian doctors in Piacenza, Italy, December 7th 1985)