ATAGI Targeted Review 2021: the national COVID-19 vaccination program.

Abstract: The overarching goal of the Australian coronavirus disease 2019 (COVID-19) vaccination program has been to protect all people in Australia from the harm caused by the novel coronavirus SARS-CoV-2. This review reflects on the role of the Australian Technical Advisory Group on Immunisation (ATAGI) in the national COVID-19 vaccination program, in terms of the initial programmatic and clinical recommendations in the evolving context of evidence relating to the disease and vaccines, epidemiology, and the program rollout. To fulfil the obligation to provide evidence-based advice to the Minister for Health and Aged Care on the safe, effective and equitable use of COVID-19 vaccines, ATAGI has worked closely with other agencies and committees such as the Therapeutic Goods Administration (TGA) and the Communicable Diseases Network Australia. ATAGI recommendations have sought to optimise the use of the available vaccine doses in achieving the objectives of preventing serious illness and death from COVID-19 while addressing any emerging safety signals following program commencement on 22 February 2021. As of mid-November 2021, the use of COVID-19 vaccines in children aged 5 to 11 years was being considered by the TGA and ATAGI; and emerging evidence, in areas such as use of heterologous vaccine schedules and co-administration with other vaccines, was under review. Despite unprecedented challenges which the delivery of mass COVID-19 vaccination presented to health systems globally, in Australia much was achieved in 2021 with over 90% coverage for primary doses in the vaccine-eligible population. Evaluation, using high quality data and assessment methods, of vaccination program outcomes-such as coverage, vaccine effectiveness and impact-is key to determine whether program objectives have been achieved and where gaps remain. Reflecting on the lessons learned so far would help further improve the national COVID-19 vaccination program and would also benefit programs for other routine vaccines and planning for future pandemics.

Vaccines for COVID-19: Where do we stand in 2021?

As of July 2021, over 3 billion doses of a COVID-19 vaccines have been administered globally, and there are now 19 COVID-19 vaccines approved for use in at least one country. Several of these have been shown to be highly effective both in clinical trials and real-world observational studies, some of which have included special populations of interest. A small number of countries have approved a COVID-19 vaccine for use in adolescents or children. These are laudable achievements, but the global vaccination effort has been challenged by inequitable distribution of vaccines predominantly to high income countries, with only 0.9% of people in low-income countries having received at least one dose of a COVID-19 vaccine. Addressing this inequity is of critical importance and will result in better control of SARS-CoV-2 globally. Other challenges include: the reduced protection from COVID-19 vaccines against some strains of SARS-CoV-2, necessitating the development of variant specific vaccines; and uncertainties around the duration of protection from vaccine-induced immunity.

COVID-19 vaccines - are we there yet?

The novel coronavirus SARS-CoV-2, the cause of the COVID-19 pandemic, is a highly infectious human respiratory pathogen to which the global population had no prior immunity. The virus will likely continue to cause significant morbidity until there is a broadly effective vaccine As of mid-December 2020, more than 200 COVID-19 vaccine candidates are in development and 11 have entered phase III clinical trials globally. All generate immunity to the viral spike glycoprotein Three vaccine candidates have agreements for procurement and use in Australia if efficacy and safety requirements are met - one protein-based vaccine, one vaccine using a simian-derived adenovirus vector and one messenger RNA vaccine. The latter two vaccines have published interim analyses and efficacy results of their phase III trials. The messenger RNA vaccine is being rolled out in the UK, USA and Canada Significant uncertainties remain. How well will some of those at highest risk of severe disease (such as older people aged >75 years and those with immunocompromising conditions) be protected by a vaccine, and for how long? Also, to what extent will vaccination protect against infection? This will determine the degree of indirect 'herd' protection needed through broad vaccine coverage of younger age groups.

Vaccines for COVID-19: The current state of play.

There is a strong consensus globally that a COVID-19 vaccine is likely the most effective approach to sustainably controlling the COVID-19 pandemic. An unprecedented research effort and global coordination has resulted in a rapid development of vaccine candidates and initiation of trials. Here, we review vaccine types, and progress with 10 vaccine candidates against SARS-CoV-2 - the virus that causes COVID-19 - currently undergoing early phase human trials. We also consider the many challenges of developing and deploying a new vaccine on a global scale, and recommend caution with respect to our expectations of the timeline that may be ahead.