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[8].⁽¹⁾

Fortunately, both ROTARIX, made up of the single G1P[8] 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[11] strain) protected against multiple strains not included in the vaccine.⁽⁴⁾

Herd Protection

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⁾

References

^{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.}