Can early measles vaccination control both measles and respiratory syncytial virus infections?

Abstract

Measles virus and respiratory syncytial virus (RSV) are two important global health pathogens causing substantial morbidity and mortality worldwide. The current measles vaccination schedule has the first dose given at 9–12 months of age and the second dose given at 15–18 months of age. Measles outbreaks have been associated with an increase in severe RSV infections in children younger than 6 months, probably as a result of measles-induced immunosuppression. A resurgence in measles cases was already occurring before the COVID-19 pandemic, which has affected global immunisation programmes, resulting in millions of children, mostly in low-income and middle-income countries (LMICs), missing out on their measles vaccine. This will leave many children living in the most vulnerable of circumstances highly susceptible to measles and RSV infections when current COVID-19 public health control measures are lifted. This Viewpoint discusses these issues and highlights the need for urgent action to address this looming crisis. The use of early measles vaccination at 4 months of age could be an effective strategy to prevent severe morbidity and death from both measles and RSV infections in many LMICs.

Respiratory Syncytial Virus and Influenza Infections in Children in Ulaanbaatar, Mongolia, 2015–2021

“…This in turn raised a crucial question of how to protect young infants effectively, especially in the context of disrupted measles immunization programs and the impact of the COVID-19 pandemic on RSV epidemiology in different LMICs settings [38,39]. Measles vaccination before 6 months of age has been shown to prevent early measles infection [40][41][42][43] and the measlesassociated immunosuppression, which in turn reduces susceptibility to nonmeasles pathogens including RSV [44]. In addition, measles vaccine has been shown to provide protection against other pathogens, either by cross protection, which has been demonstrated with RSV, or by nonspecific effects, which may lead to protection against other unrelated pathogens [45].…”

Respiratory syncytial virus, recurrent wheeze and asthma: A narrative review of pathophysiology, prevention and future directions

“…38 Immune mechanisms of indirect protection from RSV include prevention of measles-induced immunosuppression, epigenetic and metabolic adaptations to enhance innate immune responsiveness and potential B-and T-cell cross-reactivity to the measles vaccine providing some coverage against RSV infection. 38,39 Indirect immunity to many pathogens including RSV has also been described in association with the Bacille Calmette-Guérin (BCG) vaccine, 40 which has been demonstrated to reduce incidence of RSV infection, 41 hospitalisation and mortality in BCG compared to non-BCG vaccinated children. 40 It is also important to consider how RSV preventatives may impact upon subsequent risk of wheeze and asthma.…”

“…In addition to vaccines specifically targeting RSV, several alternative preventative strategies are also being explored. Early immunisation against measles, at 4 months of age rather than 6 months, has recently been suggested as a strategy to prevent severe RSV infection in vulnerable infants under 6 months 38 . Immune mechanisms of indirect protection from RSV include prevention of measles‐induced immunosuppression, epigenetic and metabolic adaptations to enhance innate immune responsiveness and potential B‐ and T‐cell cross‐reactivity to the measles vaccine providing some coverage against RSV infection 38,39 .…”

“…Early immunisation against measles, at 4 months of age rather than 6 months, has recently been suggested as a strategy to prevent severe RSV infection in vulnerable infants under 6 months 38 . Immune mechanisms of indirect protection from RSV include prevention of measles‐induced immunosuppression, epigenetic and metabolic adaptations to enhance innate immune responsiveness and potential B‐ and T‐cell cross‐reactivity to the measles vaccine providing some coverage against RSV infection 38,39 . Indirect immunity to many pathogens including RSV has also been described in association with the Bacille Calmette‐Guérin (BCG) vaccine, 40 which has been demonstrated to reduce incidence of RSV infection, 41 hospitalisation and mortality in BCG compared to non‐BCG vaccinated children 40 …”

Alveolar macrophages: Achilles’ heel of SARS-CoV-2 infection

“…Respiratory viruses are the most frequent pathogens causing human diseases, with a significant impact on morbidity and mortality worldwide. 1 In addition to influenza virus, respiratory syncytial virus, parainfluenza virus, rhinovirus and adenovirus, coronaviruses are also common circulating respiratory viruses that induce symptoms of cough, fever, sore throat, and headache. 2 – 5 Unlike conventional coronavirus subtypes, the currently spreading severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be fatal, especially the Delta variant.…”