Vaccines & Cross-Protection Across Strains
Casting a Wide Net
There are more than 60 strains of rotavirus that are known to cause disease in humans. Each strain consists of a unique combination of two types of antigens – a G type and a P type. The most common strain currently circulating worldwide is G1P.(1)
Fortunately, both ROTARIX, made up of the single G1P strain, and RotaTeq, made up of five different G and P genotypes (G1, G2, G3, G4, and P8), have been shown in clinical trials to cross-protect against a variety of rotavirus strains.(2,3) Clinical efficacy trials in India showed that ROTAVAC (made up of the single G9P strain) protected against multiple strains not included in the vaccine.(4)
Rotavirus vaccine introduction in several high-income and middle-income countries in Latin America resulted in a decline in rotavirus hospitalizations in children who were too old to have been vaccinated. New studies from different regions also found evidence of herd effects.
A Potential Added Benefit
Recent studies have found reductions in seizures following rotavirus vaccination. However, a separate study in Spain found no statistically significant link between rotavirus vaccination and seizures, highlighting the need for further research into this area.(12)
1. Bar-Zeev, N., et al., Population Impact and Effectiveness of Monovalent Rotavirus Vaccination in Urban Malawian Children 3 Years after Vaccine Introduction: Ecological and Case-Control Analyses. Clinical Infectious Diseases, 2016. 62(Suppl 2): p. S213-S219.
2. De Vos, B., et al., Live attenuated human rotavirus vaccine, RIX4414, provides clinical protection in infants against rotavirus strains with and without shared G and P genotypes: integrated analysis of randomized controlled trials. Pediatr Infect Dis J, 2009. 28(4): p. 261–266.
3. Leshem, E., et al., Distribution of rotavirus strains and strain-specific effectiveness of the rotavirus vaccine after its introduction: A systematic review and meta-analysis. The Lancet Infectious Diseases, 2014.
4. Bhandari, N., et al., Efficacy of a monovalent human-bovine (116E) rotavirus vaccine in Indian infants: a randomised, double-blind, placebo-controlled trial. Lancet, 2014. 383(993):p. 2136–2143
5. Armah, G., et al., Impact and Effectiveness of Monovalent Rotavirus Vaccine Against Severe Rotavirus Diarrhea in Ghana. Clinical Infectious Diseases, 2016. 62(suppl 2): p. S200–S207.
6. de Deus, N., et al., Early impact of rotavirus vaccination in children less than five years of age in Mozambique. Vaccine, 2017.
7. Tharmaphornpilas, P., et al., Evaluating the first introduction of rotavirus vaccine in Thailand: Moving from evidence to policy. Vaccine, 2017. 35: p. 796–801
8. Sahakyan, G., et al., Impact and Effectiveness of Monovalent Rotavirus Vaccine in Armenian Children. Clinical Infectious Diseases, 2016
9. Gheorghita, S., et al., Impact of Rotavirus Vaccine Introduction and Vaccine Effectiveness in the Republic of Moldova. Clinical Infectious
10. Leshem, E., et al., Rotavirus vaccines and health care utilization for diarrhea in the United States (2007–2011). Pediatrics, 2014. 134(1): p. 15–23.
11. Paulke-Korinek, M., et al., Herd immunity after two years of the universal mass vaccination program against rotavirus gastroenteritis in Austria. Vaccine, 2011. 29(15): p. 2791–2796
12. Orrico-Sanchez, A., et al., Lack of impact of rotavirus vaccines on seizure-related hospitalizations in children under 5 years old in Spain. Hum Vaccin Immunother, 2018. 14(6): p. 1534–1538.