RSV information and awareness platform Türkçe Frequently asked questions

Nirsevimab is not a vaccine: why terminology matters in RSV

Sağlıklı Türkiye Association

Vaccine or antibody? With new preventive interventions against RSV, accurate terminology sits at the centre of trust.

There are two distinct approaches to protecting infants against RSV, and they work in fundamentally different ways. Explaining that difference accurately is not a technical nicety; it is a question of trust.

Two different mechanisms

The maternal RSV vaccine is a vaccine. It is given to the expectant mother between 32 and 36 weeks of gestation. The mother’s immune system produces antibodies, those antibodies cross the placenta, and they protect the baby in the first months of life.3

Nirsevimab is not a vaccine. It is a long-acting monoclonal antibody. It does not train the baby’s immune system; it gives the baby ready-made antibodies directly. It is given as a single dose and provides passive protection for roughly five to six months — one RSV season.2

The difference may look like a detail of language. It is not.

Why it matters so much

Vaccine hesitancy is too multi-layered a phenomenon to be reduced to a lack of information; it has psychological, sociological, cultural, political, structural and institutional-trust dimensions.4 Against that background, terminological ambiguity becomes a source that feeds hesitancy.

A parent who does not clearly understand what a product is remains defenceless against the misinformation circulating about it. Describing nirsevimab as “a new vaccine” is terminologically inaccurate and may contribute to existing anxieties about vaccines being directed at it as well.

A recent study in Türkiye shows the COVID-19 period adversely affected parents’ confidence in vaccines.7 That suggests the loss of confidence was not confined to one vaccine but fed a broader climate of doubt around routine childhood vaccines and new immunisation products.

Research from Italy likewise found limited awareness of RSV and related preventive interventions among health professionals and patients alike.8 The need for terminological clarity is not confined to parents.

How it should be communicated

Presenting scientific data alone is not enough to reduce hesitancy. The form and tone of communication, how concerns are handled, and who delivers the message matter at least as much as the content. Blunt corrective messaging, accusatory language or fear tactics can in some circumstances reinforce false beliefs.5

The framework that emerges from the literature:

  1. Convey scientific consensus plainly.
  2. Explain uncertainty honestly — possible side effects, safety signals, data limitations.6
  3. Support decision-making without belittling concerns.
  4. Make decision processes, conflicts of interest and reasoning transparent.
  5. Clarify terminology.1

The last item is not on the list by accident. Conveying clearly that nirsevimab is not a vaccine but a long-acting monoclonal antibody used within an immunisation strategy is defined as a direct component of building trust.1

In short

Using the right word is not an attempt to persuade anyone. It is the precondition for a parent making their own decision while genuinely knowing what it is they are deciding about.

Sources

  1. Esposito, S., Fainardi, V., Capra, M. E., Aricò, M., Lanzoni, A., Campana, B. R., Niceforo, M., Neglia, C., Valletta, E., & Biasucci, G. (2025). Acceptance of nirsevimab for the prevention of respiratory syncytial virus infection in neonates: A cross-sectional survey in Emilia-Romagna, Italy. Vaccines, 13(9), 896. doi.org/10.3390/vaccines13090896
  2. Hammitt, L. L., Dagan, R., Yuan, Y., Baca Cots, M., Bosheva, M., Madhi, S. A., Muller, W. J., Zar, H. J., Brooks, D., Garcia-Garcia, M. L., Principi, N., Xu, X., Wang, J., Zhang, B., Udata, C., & Griffin, M. P. (2022). Nirsevimab for prevention of RSV in healthy late-preterm and term infants. New England Journal of Medicine, 386(9), 837–846. doi.org/10.1056/NEJMoa2110275
  3. Kampmann, B., Madhi, S. A., Munjal, I., Simões, E. A. F., Pahud, B. A., Llapur, C., Baker, J., Pérez Marc, G., Radley, D., Shittu, E., Soni, P., & Jansen, K. U. (2023). Bivalent prefusion F vaccine in pregnancy to prevent RSV illness in infants. New England Journal of Medicine, 388(16), 1451–1464. doi.org/10.1056/NEJMoa2216480
  4. MacDonald, N. E. (2015). Vaccine hesitancy: Definition, scope and determinants. Vaccine, 33(34), 4161–4164. doi.org/10.1016/j.vaccine.2015.04.036
  5. Whitehead, H. S., French, C. E., Caldwell, D. M., Letley, L., & Mounier-Jack, S. (2023). A systematic review of communication interventions for countering vaccine misinformation. Vaccine, 41(5), 1018–1034. doi.org/10.1016/j.vaccine.2022.12.057
  6. Iannizzi, C., Andreas, M., Bohndorf, E., Hirsch, C., Zorger, A.-M., Brinkmann-Paulukat, J., Bormann, B., Kaufman, J., Lischetzki, T., & Monsef, I. (2025). Communication-based interventions to increase COVID-19 vaccine willingness and uptake: A systematic review with meta-analysis. BMJ Open, 15(5), e072942. doi.org/10.1136/bmjopen-2023-072942
  7. Teker, A. G., Yüce, H. N., Erkal, Ç. E., Sağlam, G., Çatar, A., Uçar, Y., Yılmaz, S., & Aklan, Ş. Y. (2026). Vaccine hesitancy regarding childhood vaccinations among parents. The Journal of Pediatric Research, 13(1), 45–52.
  8. Micheletto, C., Lorenzini, G., De Grazia, S., Di Marco, F., Di Matteo, R., Faverio, P., Gramegna, A., Vicentini, M., & Blasi, F. (2025). Awareness of respiratory syncytial virus and other respiratory disease vaccines among healthcare professionals and their patients in Italy. Human Vaccines & Immunotherapeutics, 21(1), 2552557. doi.org/10.1080/21645515.2025.2552557

The information on this site is for general guidance only and does not replace examination, diagnosis or treatment by a clinician.

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