Professor Karina Butler:

The national immunisation advisory committee, NIAC, welcomes the opportunity to contribute to the discussion regarding the roll-out of Covid19 vaccination. I am here today in my capacity as chair of that committee. It is less than one year since any one of us first heard of Covid. Since then, globally, more than 72 million people have been infected and just over 1.6 million have died. In Ireland, there have been more than 76,000 cases and 2,000 deaths. Spurred by the urgency of the problem, it has taken scientists less than one year to develop effective vaccines. We are now preparing for the roll-out of potentially three, but likely six, different Covid vaccines over the coming year.

Even just two to three years ago, the speed at which this has happened was inconceivable. However, although rapid, it has not been rushed or reckless. Rather, the speed is a reflection of the extraordinary advancements in the vaccination field that were under way before Covid19, harnessed together with unprecedented scientific co-operation and financial and human resource investment. In the case of Covid, there was already much vaccine research that could be built on to facilitate rapid development of the vaccines and compress usual timelines. Covid19 vaccine development was a single common global priority. Large-scale investment both in human resource and finance enabled many steps to be undertaken in parallel and with much greater efficiency. As Covid19 was, unfortunately, all too common and people were eager to help in finding a solution, recruitment to clinical trials was rapid. Similarly, as symptomatic Covid19 and severe Covid disease were also very common, clinical trial endpoints, that is, reaching the point in a trial where one is able to tell if there was a difference between the vaccinated and unvaccinated, were quickly reached.

Vaccine safety is an overriding concern. With vaccination, a higher safety bar is required than for most other medical interventions, as vaccines are administered to healthy individuals or those with stable underlying medical conditions. Most adverse events following immunisation have onset within six weeks of vaccination. Thus, a minimum median follow up of two months was required prior to evaluation of the clinical trial data by the regulatory agencies. As with all newly licensed vaccines, it is possible that some rare or very rare, less than 1:10,000, adverse events following immunisation, AEFI, particularly those unique to specific populations, may not be known when the Covid19 vaccines are authorised. Thus, it is critically important that, as planned, continued surveillance in the post-marketing phase is undertaken when vaccines will be administered not to tens of thousands but millions of individuals.

The Pfizer-BioNTech vaccine is likely to be the first Covid19 vaccine administered in Ireland. Data from the randomised phase 3 trial based on more than 36,000 participants demonstrated vaccine efficacy of 95% in those aged 16 and over. There were nine cases of Covid19 in almost 20,000 vaccinated participants compared with 169 cases in a similar number of placebo recipients. These results far exceeded what had been hoped. It can be anticipated however that, as vaccine is rolled out in the real world, the effectiveness is likely to drop a little compared to the very controlled clinical trial situation.

Regarding safety, local site reactions and, less commonly, more general shortterm systemic reactions such as fatigue, flu-like symptoms and fever, can be anticipated. These events occurred at increased frequency following the second vaccine dose and were more common in the younger rather than older age groups. These effects are partly a result of the efficacy of the vaccines in stimulating the immune response. We will know more detail about the side effects when the licence documentation is published by the EMA. Reports from the regulatory agencies in the United States, the United Kingdom and Canada raised no significant safety concerns. Reports of anaphylactic-type reaction in two vaccines in the UK outside of the clinical trial naturally draw attention. Vaccine-associated anaphylaxis or severe immediate allergic reaction is extremely rare. It is estimated to occur at 1.31 per million vaccine doses. Its occurrence in the UK is being investigated. Continued surveillance data is needed to determine whether this was a chance occurrence or whether the Pfizer-BioNTech Covid19 vaccine is associated with a higher risk of allergy compared with other vaccines.

It is standard practice for vaccinations to be administered by trained health professionals who are appropriately trained in the management of anaphylaxis and have the appropriate equipment available. Where there is doubt, rather than forgoing the benefits of vaccination, appropriate advice should be sought from the relevant specialist or the local immunisation team. NIAC was asked to advise regarding prioritisation for vaccination, given that there will be limited vaccine supply in the initial phases of the rollout. Recommendations were informed by local epidemiology, focused on the key objectives to prevent Covid19 associated disease and death, while striving to ensure equitable access with attention to the ethical principles of moral equality, minimising harm, fairness and reciprocity. Recommendations are based on the currently available evidence and are subject to updating and refinement as data pertaining to risk groups is refined, vaccine availability increases and as even more data regarding the different vaccines is collated and analysed. The document should be regarded as a living document and subject to updating. In summary, this is an exciting time when we can be filled with hope that we are being equipped to begin a path back towards a more normal lifestyle. This will not happen overnight.

There are many challenges ahead, including providing clear, accurate, and up-to-date information to potential vaccine recipients such that they can feel fully informed of the potential benefits, the direct benefit in preventing Covid19 for themselves, the benefit of reducing the case numbers for our communities and to accurately balance that against any small but as yet unknown risks that might be associated with vaccinations.

A further challenge is to finalise the development of a national injury redress program to provide support and care in the event that any vaccine recipient develops a serious vaccine reaction as recommended by the WHO. We have been relatively lucky in Ireland. Our case numbers are remarkable given what has happened in many other countries in Europe and elsewhere. Data have shown that in early autumn we were on an identical trajectory to other countries. Significant restrictions impacting how we live and causing significant economic hardship for some, has brought relief from spiralling case numbers. However, we cannot continue to depend indefinitely on those measures.

Vaccination is the key that will help open that pathway back to normality. It is very our hope that in time, this virus will be listed along with other infections such as diphtheria and polio as organisms that vaccination has controlled, if not completely conquered.