Do Moderately Preterm Infants need RSV Immunization? What use are numbers without a denominator?

Palivizumab is an enormously expensive medication, an antibody which is given intramuscularly about once per month to at-risk infants to prevent infection with the respiratory syncytial virus (RSV). Recently the AAP and the CPS have changed their recommendations to reduce the number of preterm babies who are eligible for it. Most babies who are slightly or moderately preterm will no longer be eligible for prophylaxis, the decision being largely because the benefits of RSV prophylaxis are not matched by the huge costs.

It is clear that palivizumab decreases both the incidence and severity of RSV infections. So its use is really only a question of cost-benefit. Costs being the monetary cost of the medication, and in addition the “cost” of a monthly intramuscular injection and its administration. If it were not for these costs then you could give palivizumab to everyone. It is to the financial benefit of the medication’s producers to emphasize the benefits of prophylaxis, while not talking about the costs, and not even trying to figure out the incidence of the problems that they are aiming to prevent.

The last sentence of this new paper you could write about absolutely any group of newborns:

Preventing severe RSV disease in this population would provide substantial health benefits, particularly during the first months of life when RSV disease incidence and severity are highest.

It may be no surprise to discover that this paper (paid for open access (by AstraZeneca), unlike most publications in this journal) was funded by AstraZeneca, who are the current producers of palivizumab; it was written by a medical writing company paid by AstraZeneca, has a corresponding author who works for AstraZeneca, and has multiple authors who have other links with AstraZeneca.

What this paper tells us is that some infants who did not get prophylaxis will catch RSV (we don’t know from this paper if that is more than babies who did get prophylaxis) some of them get very sick (we don’t know from this paper if that is more than babies who did get prophylaxis) and it costs a lot of money (we don’t know from this paper if that is more than babies who did get prophylaxis).

The paper gives no indication of how many potentially affected babies were involved, there is no denominator.

There were 702 babies with confirmed RSV disease which was community acquired. For some reason, which is not clear to me from this publication, they only give good information for 219 babies who were “enrolled”. I have read this paper a couple of times (only for the purposes of this blog; otherwise it would have quickly ended up in the metaphorical garbage can: the things I do for my gentle readers…) and I can’t figure out who was enrolled and why, compared to the non-enrolled babies, so we don’t know if the third who were enrolled were representative of the entire cohort.

The information we really need in order to decide who should get palivizumab is the following: how much does it cost if we give 10,000 34 (or 33 or 35) week gestation babies palivizumab prophylaxis, and how much does it cost if we don’t.

Studies designed, paid for, performed, written, and published, by the people who manufacture palivizumab are not likely to help us very much.

But even better would be studies that show how, now that all the R&D costs of the development of palivizumab have been recouped many times over, we can ensure that the price of palivizumab is reduced to reflect “production costs with a reasonable profit margin”; rather than “as much as we can possibly get away with”.

About Keith Barrington

I am a neonatologist and clinical researcher at Sainte Justine University Health Center in Montréal
This entry was posted in Neonatal Research. Bookmark the permalink.

2 Responses to Do Moderately Preterm Infants need RSV Immunization? What use are numbers without a denominator?

  1. anniejanvier says:

    The title for this blog post is very polite for a BBP (Barrington Blog Post)!

  2. Great blog post – I think palivizumab is the most successfully marketed drug ever (so far) in neonatal care – given its relatively smaller efficacy on an outcome that is very much context-dependent. The company strategies could be a case study in marketing!

    I would like to see an independent investigator-initiated trial on RSV prophylaxis.

    One thing that is certain also – admissions due to bronchiolitis increase – whether this is depending on a truly increased incidence or a different parental/health-care-provider behaviour that would be interested to study further. See this interesting data from the UK

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