“No jab, no pay” empirically causes a 65% increase in vaccination.

We report the first AIR data analysis to evaluate changes in catchup vaccination of children and adolescents in Australia after the introduction of the “No jab, no pay” policy. We found substantial catch-up vaccination activity among children against selected vaccine-preventable diseases after the implementation of this policy. Catch-up DTPa3 vaccination activity was 65% higher during the first two years of “No jab, no pay” than during the baseline period (15.5% v 9.4%). In the two years immediately following its introduction, people aged 7 to less than 20 years received nearly 87 000 catch-up MMR2 doses and about 31 500 catch-up DTPa3/ dTpa3 doses. The marked mid-year peaks in catch-up vaccination activity in 2016 and 2017 suggest a link with “No jab, no pay”, as vaccination requirements for all relevant family assistance payments were assessed at the end of each financial year (July; but fortnightly for Child Care Subsidy since 1 July 2018). The lower level of peak catch-up activity in 2017 than in 2016 suggests that the major impact of the new policy was in its initial year.

We found that MMR2 catch-up vaccination increased coverage among people aged 10 to less than 20 years from 86.6% in 2015 to 89.0% to 2017; this was an important increase, although to a level still below the 95% coverage across all age groups needed to prevent the spread of measles. A considerable proportion of cases in the largest recent measles outbreak in Australia (Sydney, 2012) were in this age group (49 of 168, 29%).19 While endemic measles has been eliminated in Australia, outbreaks linked to imported disease still occur. Maximising MMR vaccination coverage across all age groups is important for maintaining elimination, particularly given the large increases in measles case numbers in many countries during 2018–19.20

High MMR coverage is also needed to maintain the elimination of endemic rubella in Australia, certified by the World Health Organization in 2018;21 catch-up rubella vaccination of adolescent girls is particularly important to prevent the severe effects on fetuses of congenital rubella infection.

We focused on two vaccines as proxies for catch-up vaccination in general, but other vaccines that may be missed in early childhood or are required by people with particular medical conditions are also important but insufficiently delivered to adults.22 Vaccination of young people and adults should be more readily monitored as the AIR matures, including through the transfer of data from jurisdictional school-based vaccination programs. We found that MMR2 catch-up vaccination after the introduction of “No jab, no pay” was markedly higher in the lowest than in the highest socio-economic status areas. This is consistent with a larger proportion of families in disadvantaged areas being eligible for means tested family assistance and for whom the “No jab, no pay” policy was therefore relevant. That catch-up vaccination activity was twice as high among Indigenous as among non-Indigenous children and young people is similarly attributable to the greater proportion of Indigenous families eligible for family assistance payments; average disposable income for Indigenous people aged 15 years or more is 30% lower than for non-Indigenous Australians.23 The lower rate of catch-up activity in remote areas may indicate poorer access to vaccination services. Our data confirm that the financial penalties of the “No jab, no pay” policy have an unequal impact on Australian families, with smaller gains in vaccination coverage of children of higher socio-economic status. Investigating regional and sub-regional impacts of the policy, especially in areas with persistently lower coverage, would be useful.

Limitations

Given the cross-sectional design of our study, changes in catchup vaccination activity may not be attributable to the “No jab, no pay” policy alone. For example, some children may have been vaccinated for other reasons, such as overseas travel, preenrolment requirements for further study (eg, in health-related professions), or because of changes in attitude to vaccination unrelated to “No jab, no pay”. We could not determine whether catch-up activity among young people over 7 years of age increased with “No jab, no pay” because pre-2016 data were not available for this age group.

We may have overestimated the number of older children and adolescents who were not up to date with vaccinations at the start of the “No jab, no pay” period, as some may have received catch-up vaccinations not recorded by the age-limited ACIR before 2016. However, we probably underestimated the number of catch-up vaccinations after 2016, as some may not be recorded in the AIR. Taking these factors together, the estimated proportions of older children and adolescents receiving catch-up vaccinations are probably conservative.

Further, we could not separate the effects of “No jab, no pay” monetary sanctions from those of other measures, some of which were introduced at the same time as “No jab, no pay”, including expanding the availability of free catch-up vaccines for older children and adolescents. State-based “No jab, no play” policies should not have affected our findings as they target children under 5 years of age. Finally, the AIR does not include information on sociodemographic factors such as ethnic background, country of birth, and family size. Linkage with other large databases containing such information is essential for fully evaluating the effects of population-level vaccination policies.

Conclusion

A considerable degree of catch-up vaccination activity followed the introduction of “No jab, no pay” in Australia. This should help facilitate disease control, including protecting against a resurgence of measles. Our findings suggest that, while monetary sanctions are effective in promoting catch-up vaccination, their impact varies with socio-economic disadvantage. A number of overseas governments have shown interest in various types of compulsory vaccination policy.24 Many factors contribute to incomplete vaccination; a comprehensive suite of measures, particularly for reducing barriers to access and incorporating systematic reminders, is therefore essential for improving coverage.15,24 Finally, the ethical aspects and unintended consequences of “No jab, no pay” and “No jab, no play” policies should also be carefully examined, as recommended for any country considering such measures.7,25