The very cautious decision of the National Immunisation Advisory Council (Niac) to recommend that the AstraZeneca vaccine be given only to those over 60 years has sent the Health Service Executive scrambling to revise a vaccination programme that had finally appeared to be gathering momentum.
A short-term hit to the programme is inevitable. Whether it also does long-term damage depends primarily on two things: effective communication and the pace of vaccine delivery.
There is no right or wrong answer to the dilemma posed by the news of a plausible connection between the AstraZeneca vaccine and a rare blood clot. The evidence suggests the risk of death is very small indeed – about one in a million – but any public health medic would be cautious when confronted with such a severe potential outcome. Niac had to balance the risk of serious illness from Covid-19, which is much higher among older people, against the risk of this rare side-effect, which is more common in young people. In drawing the line at 60, it took the same position as authorities in France, Germany and Italy. The UK and Greece are offering the product only to those over 30 while many other countries have not imposed any restrictions.
Inevitably the shift will worry people, not least those in their 60s (the over-70s should continue to receive the Pfizer or Moderna shots; otherwise they would be waiting until the end of July for full protection). Effective communications are therefore vital. The public cannot be reminded too often that all four approved vaccines are extremely effective at keeping people of all ages out of hospital. The recommendation also shows the close vigilance that the State applies to the vaccines.
Unfortunately that messaging risks being undermined by failures of implementation: for example, thousands of people were told late on Monday night that they should not attend their AstraZeneca appointments on Tuesday even though many of those with appointments had not been told what vaccine they were due to receive. Given that Niac had been deliberating over this since last week, cancellations could have been ordered in advance. It will also raise eyebrows that the effects on the vaccination programme were not known to and considered by Niac.
Ultimately, everything now hinges on vaccine supply. And on this, the HSE suffered a second blow within 24 hours yesterday when Johnson & Johnson paused deliveries of its one-shot vaccines in Europe after US authorities paused the rollout there due to concerns over a possible link to rare blood clots.
On its own, the AstraZeneca decision did not necessarily make the State’s vaccination targets unreachable. But taken together with an extended Johnson & Johnson pause, the task would become very difficult indeed.