19th January 2018, Volume 131 Number 1468

Effectiveness of a third dose of MMR vaccine for mumps outbreak control

Immunisation with two doses of the measles-mumps-rubella (MMR) vaccine as part of a childhood vaccination programme led to a 99% reduction in reported cases of mumps. In the US however, there have been many recent outbreaks of mumps even in those vaccinated. This report concerns a study which has evaluated the effectiveness of a third dose for outbreak control and assessed for waning immunity.

Over 20,000 university students were involved. 98.1% had received two doses of MMR. Over 4,000 were given a third dose of MMR. The subsequent incidence of mumps was significantly reduced in those who had been given a third dose of MMR.

These findings suggest that the campaign to administer a third dose of MMR vaccine improved mumps outbreak control and that waning immunity probably contributed to propagation of the outbreak.

N Engl J Med 2017; 377:947–56

Risk of post-pregnancy hypertension in women with a history of hypertensive disorders of pregnancy

What is the timing and trajectory of post-pregnancy hypertension risk after hypertensive disorders of pregnancy? This is the topic reviewed in this comprehensive study from Denmark.

The authors estimated cumulative incidences of post-pregnancy hypertension over the decade after a first birth in women with and without hypertensive disorders of pregnancy. Approximately 500,000 women were involved in the study. Among women with a hypertensive disorder of pregnancy in their first pregnancy, 14–32% (depending on age at delivery) developed hypertension in the decade post-partum, compared with 4–11% of women with normotensive first pregnancies.

The high risk persists for more than 20 years. The researchers suggest that cardiovascular disease prevention in these women should include blood pressure monitoring initiated soon after pregnancy.

BMJ 2017; 358:j3078

Exenatide once weekly versus placebo in Parkinson’s disease

Exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, has neuroprotective effects in preclinical models of Parkinson’s disease.

In this paper, the researchers report on a randomised placebo controlled trial on the use of this drug in the clinical setting. Sixty-two patients with moderate Parkinson’s disease were randomised to receive a weekly subcutaneous injection of 2mg of exenatide or placebo for 48 weeks in addition to their regular medication.

The neuroprotective effects noted in the preclinical models were also seen in this randomised trial. The conclusions reached were that exenatide had positive effects on practically defined off-medication motor scores in Parkinson’s disease, which were sustained beyond the period of exposure. Whether exenatide affects the underlying disease pathophysiology or simply induces long-lasting symptomatic effects is uncertain. Exenatide represents a major new avenue for investigation in Parkinson’s disease, and effects on everyday symptoms should be examined in longer-term trials.

Lancet 2017; 390:1664–75