ANALYSIS:The statistical reality is that cervical cancer vaccination remains a safe and effective preventive measure, writes DR MUIRIS HOUSTON
THE UNFORTUNATE death of a 14-year-old girl within hours of receiving a vaccine against cervical cancer represents every parent’s worst nightmare.
Having given consent for their daughter to participate in a national immunisation programme against the human papilloma virus (HPV), her parents must now be wishing they had said no.
While the NHS Trust has said Natalie Morton had a “serious underlying medical condition” and that the vaccine was unlikely to have caused her death, it is difficult to be definitive as to the cause of her death, particularly without the results of a postmortem examination. We as yet do not know her full medical history; nor have any details of the symptoms she experienced immediately after the jab emerged.
These details are especially important in deciding whether a severe allergic reaction to the vaccine occurred.
Although extremely rare, anaphylactic shock can occur following the administration of a drug or vaccine. When a patient suffers severe anaphylaxis, their blood pressure drops precipitously. The lips and tongue swell up to the point where breathing becomes a challenge. And as the airways in the lungs narrow, shortness of breath and wheezing add to the breathing problems.
Without skilled medical intervention, anaphylaxis can be fatal; however, with the correct drugs and equipment, the person’s life may be saved.
With 1.4 million doses of the Cervarix vaccine administered in the UK to date, some 5,000 adverse reactions have been recorded. Just over 400 allergic reactions have been noted, the vast majority of which were mild. If Natalie Morton’s death was due to an allergy to the vaccine, it must have been because of rapid and severe anaphylactic shock.
The most comprehensive information about HPV vaccine safety has emerged from the US. In August, a paper published in the Journal of the American Medical Association detailed the results of adverse reactions to the cervical cancer vaccine.
The Vaccine Adverse Event Reporting System is a national voluntary surveillance system, which aims to track vaccine safety after a new product has been licensed for general use. It found almost 54 adverse events per 100,000 HPV vaccines given. Some 6 per cent were classified as serious reactions, with 3.1 allergic reactions per 100,000 doses. Just 0.1 events per 100,000 were classed as full-blown anaphylaxis.
Other serious but rare side-effects included blood clots and Guillain-Barre syndrome (a disorder whereby the body’s immune system attacks the nervous system).
The decision on whether to vaccinate a child against cervical cancer revolves around a calculation of the potential risks versus the possible benefits.
Even if this tragedy is found to be a direct result of the vaccine, it will not change the statistical reality that the vaccine remains a safe and effective preventive health measure.