Contents

17 Rotavirus

17.4 Vaccines

17.4.1 Available vaccines

The types of virus assessed for use as rotavirus vaccines have included live attenuated virus, both human and animal strains of the virus, and human–animal reassortant viruses. There are two vaccines registered (approved for use) and available (marketed) in New Zealand. Both are orally administered, live attenuated vaccines. The live attenuated vaccine viruses replicate in the intestinal mucosa and are shed in the stools of vaccine recipients.23–25

Funded vaccine

RV5 (RotaTeq, MSD) is a pentavalent bovine–human reassortant vaccine representing the common viral protein types G1−4 and P[8]. Each dose contains at least 2.0 x 106 infectious units per dose, depending on serotype. Other components and residuals include sucrose, sodium citrate, sodium phosphate monobasic monohydrate, sodium hydroxide, polysorbate 80 and culture medium. There are no preservatives or thiomersal.

Other vaccine

The other rotavirus vaccine registered and available in New Zealand is:

17.4.2 Efficacy and effectivenessTop

Prevention of disease

A 2012 Cochrane review26 of the efficacy of rotavirus vaccines for the prevention of rotavirus diarrhoea assessed 41 trials which met the inclusion criteria, involving 186,263 enrolled participants. Of these, 29 trials assessed the monovalent vaccine (RV1; Rotarix) and 12 trials assessed the pentavalent vaccine (RV5; RotaTeq).

For the first two years of life in countries with low mortality rates, both vaccines prevented over 80 percent of cases of severe rotavirus diarrhoea (Table 17.1). Both vaccines probably have an effect on severe all-cause diarrhoea (moderate to low quality of evidence).

Table 17.1: Cochrane review: percentage of severe rotavirus and all-cause diarrhoea cases prevented in children by RV1 and RV5, compared to placebo (low mortality rate countries)

Vaccine Percentage of cases prevented Risk ratio
(95% confidence interval)
Number of participants (number of trials) Quality of evidence
Severe rotavirus diarrhoea: infants aged under 1 year
RV1 86 0.14
(0.07–0.26)
40,631
(6)
High
RV5 87 0.13
(0.04–0.45)
2344
(3)
Moderate
Severe rotavirus diarrhoea: children aged under 2 years
RV1 85 0.15
(0.12–0.2)
32,854
(8)
High
RV5 82 0.18
(0.07–0.5)
3190
(3)
Moderate
Severe all-cause diarrhoea: infants aged under 1 year
RV1 40 0.60
(0.5–0.72)
17,867
(1)
Moderate
RV5 72 0.28
(0.16–0.48)
1029
(1)
Low
Severe all-cause diarrhoea: children aged under 2 years
RV1 37 0.63
(0.56–0.71)
39,091
(2)
Moderate
RV5 96 0.04
(0.00–0.70)
5916
(1)
Low

Source: Adapted from: Soares-Weiser K, MacLehose H, Bergman H, et al. Vaccines for preventing rotavirus diarrhoea: Vaccines in use. Cochrane Database of Systematic Reviews 2012, Issue 11, Art. No. CD008521. DOI: 10.1002/14651858.CD008521.pub3 (accessed 12 August 2013).

Partial vaccination

Studies in partially vaccinated infants (ie, who have not completed the three-dose course of RV5 or the two-dose course of RV1) found that protection against rotavirus ranged from 51 to 55 percent in low- and middle-income countries, and from 69 to 93 percent in high-income countries.27

Cross-protection

Rotavirus vaccine strains vary considerably, and multiple strains can occur at the same time. In developed countries, both vaccines appear to provide some cross-protection against non-vaccine serotypes.28, 29

Duration of protection

Prior to the introduction of rotavirus vaccines in Europe, extension studies of the pivotal phase III RV5 trial showed protection lasting up to three years from the last vaccine dose.30 The duration of protection provided by rotavirus vaccines is difficult to measure because of the herd immunity effect that occurs after the vaccine is implemented. Some studies indicate waning immunity after the first year of life, particularly in developing countries.31, 32

Effectiveness

Post-licensure surveillance studies have demonstrated large reductions in rotavirus-positive stool isolates from children with gastroenteritis (US)2 and in diarrhoea-related deaths (Mexico).33, 34 Summarised, post-licensure vaccine effectiveness studies in high-income countries have shown an 89–100 percent reduction in emergency department visits or hospitalisation, a 74–90 percent decline in hospitalisations for rotavirus gastroenteritis in children aged under 2 years, and a 29–50 percent decline in ‘all-cause’ acute gastroenteritis hospitalisations for children aged under 5 years.35

Following vaccination, vaccine viruses are shed in the stool and they may be transmitted from vaccinated to unvaccinated children. This may contribute to providing herd immunity.36 Post-market surveillance studies in the US2, 37 and Australia38 have shown significant declines in rotavirus gastroenteritis among unvaccinated populations, suggesting indirect benefits from reduced transmission in the community. Herd immunity effects have also been noted after routine vaccination in El Salvador, Panama, Mexico and Austria.39

17.4.3 Transport, storage and handlingTop

Transport according to the National Guidelines for Vaccine Storage and Distribution.40 Store in the dark at +2oC to +8oC. Do not freeze.

17.4.4 Dosage and administrationTop

The dose of RV5 (RotaTeq) is 2.0 mL, administered orally (see the package insert for administration instructions).

The three-dose course should be started before age 15 weeks (ie, 14 weeks and 6 days) and completed by age 8 months and 0 days. If a partially vaccinated infant reaches age 8 months before the third dose is given, the first or second doses already given will offer them some protection against disease.

Co-administration with other vaccines

Rotavirus vaccines can be administered at the same time as other scheduled vaccines. Note that no time interval is required between administration of rotavirus and BCG vaccines.

Interchangeability

Some infants may have commenced their immunisation course with RV1. There is no data on the interchangeability of RV1 and RV5. A complete course with one vaccine is preferable but, if necessary, a series that contains both vaccines is preferable to an incomplete series.1 There are not expected to be any safety concerns if an infant starts on one vaccine and completes on another, provided that the upper age limit and inter-vaccine interval, as defined in section 17.5.2 below, are met.