In order to attack the merits of childhood immunization, the anti-vaccine movement not only exaggerates the dangers of vaccines, but downplays the seriousness of the diseases they protect against. However, truth does not bend to these ideological interests, and it turns out that measles, whose vaccine is often criticized by anti-vaxxers, has an extra bit of nastiness we were not previously aware of.

Years after the obvious effects of measles have passed, the disease can still make breathing more difficult. Middle-aged adults are more likely to suffer from chronic obstructive pulmonary disease (COPD) if they have had measles in the past. A study published in Respirology found people without other risk factors are unaffected by past measles status. However, adults who smoked heavily, or for an extended period, had their already raised risk of COPD increased further if they suffered from measles as a child.

Dr Jennifer Perret of the University of Melbourne used a sample of 1,389 people who were born in Tasmania in 1961 and had their lung function measured in their mid-40s. Since these people grew up before the measles vaccine was widely available, 69 percent had suffered from the disease as children. Once they recovered they probably thought that it was behind them, and for those who never smoked heavily, it appears likely it was.

As with just about everything, smoking makes the risk of COPD worse, but Perret found the combination with measles is particularly dangerous. Measles, a history of smoking, and being prone to asthma was the worst combination of all.

Perret told IFLScience; “It is unclear how measles damages the airways, and previous long-term studies have not found direct effects of childhood measles on adult airway function.” For the subgroup made vulnerable by their smoking and asthma, however; “We hypothesize that there might be a degree of small airway narrowing with associated changes in immune function,” Perret continued. This, she and her co-authors believe, may not be detectable unless other factors re-enforce it.

Perret made the discovery as part of a wider project researching the long-term consequences of childhood infections. She added that additional research is needed, not only to confirm that the findings are not some strange effect limited to Tasmanians, but to see whether measles has other subtle legacies that we have missed.

COPD is determined by long-term shortness of breath. It can refer to irreversible chronic asthma, bronchitis, or emphysema. Increasing the risk is just another reason why measles is definitely not marvelous.