Since the start of the pandemic, Australia’s border closures, strict social distancing policies, mask wearing mandates, and diligent testing and tracing practices have all become part of the landscape and have helped to keep me safe. So, when vaccines started to rollout, I was pretty excited that this huge step would allow us to get on with our lives.
Australia routinely achieves high rates of vaccination so I was confident that our community would enthusiastically roll up their sleeves to get the jab when it became available. I was wrong. As the side effects of vaccines became front page news, vaccine hesitancy grew. However in May, an Australian came out of hotel quarantine with the B.1617.1 variant which led to an exponential increase in cases in Melbourne. We went back into lockdown and schools closed again. The only good news is that we have been jolted out of our complacency; finally, Australians are queuing to be immunised. Like many other countries, the bad news is lack of vaccine availability.
This raises questions about who will benefit most from the vaccine, and whether adolescents should be vaccinated. In early May, Health Canada authorised the Pfizer BioNTech vaccine for 12-15-year-olds, based on data from the Phase III clinical trial which enrolled 2,260 young adolescents in the US. The US Food and Drug Administration followed shortly afterwards, extending the Emergency Use Administration of the Pfizer BioNTech vaccine from 16-yr-olds down to 12-yr-olds. At the end of May, the EU medicines agency also approved the Pfizer BioNTech vaccine for 12-15 year-olds, with Germany being the first country to endorse that recommendation. Other countries are likely to come under increasing pressure to extend immunisation to adolescents.
This is clearly positive as while the risk of disease and death increases with age, adolescents are also at risk of COVID-19. For example, in the US, around 66% of adolescents with Multisystem Inflammatory Syndrome required admission to ICU and 2% died. In the UK, there were 651 admissions of children and adolescents with COVID19 in the first 6 months of 2020, of whom 1% died (all with profound comorbidities). However the risks of vaccination need to be weighed against the risk of disease, including the rare sides effects of myocarditis and pericarditis in mRNA vaccines that appear most prevalent in the young. Adverse events monitoring in adolescents will be critical to gaining a fuller understanding of vaccine safety in due course.
Particularly in low income countries, where young people make up a far greater proportion of the population than in wealthier countries, there may well be public health benefits from immunising adolescents as herd immunity would be more quickly reached – presuming a vaccine is available. Yet these are the same countries that are struggling to vaccinate their front-line health workers and the elderly, groups that are at immeasurably greater risk of dying from COVID19 than adolescents. Individual countries with limited access to vaccines must continue to prioritise the most vulnerable.
Yet COVAX, the global initiative to drive fair vaccine distribution, continues to struggle with limited vaccine supplies. Does encouraging vaccination of adolescents in high income countries with low transmission rates reduce the availability of vaccines for older more vulnerable adults in countries with poor quality health care systems that risk being simply overwhelmed by infections? Notwithstanding another lockdown in Melbourne, adolescents are still at extremely low risk of infection. If a vaccine were authorised for adolescents here, should we target adolescents or should we try to influence our politicians to preferentially direct those vaccines to adults in neighbouring countries at far greater risk, such as Papua New Guinea?
I am reminded of the early days of the HPV vaccine, and the reluctance of many parents to immunise their daughters, believing that they didn’t need it (yet) or fearful that immunisation would encourage sexual activity. In time, I remember the relief of being able to cite the science that showed that younger adolescents developed a stronger immune response than older adolescents. I am also reminded that we now immunise both boys and girls against HPV in Australia, in response to local statistical modelling of the benefit cost ratios. I am well aware that too many countries still don’t have strong HPV vaccine rollout for girls, but I also appreciate that the money that would be saved by not immunising boys in Australia would be most unlikely to be added to GAVI initiatives. Sadly, developmental assistance is not a zero-sum game.
I expect that in time, adolescents will indeed be immunised against COVID-19. Yet given the state of the science, the ethics of immunising adolescents as a herd immunity strategy to ‘mop-up’ adult fearfulness or vaccine complacency does not sit well with me. I similarly struggle with the ethics of vaccinating adolescents in the global north while older populations and front-line health workers in the global south continue to die in such large numbers. The choices remain challenging in the context of us living in such a very small world, where none of us is safe until all of us are safe.