Vaccines sometimes create unwarranted health fears, but whether or not vaccinating against chickenpox is genuine has been a matter of medical debate.
It’s a regular childhood jab in some countries, including the US, Canada, Australia, Japan and about half of Europe – but hold-outs include the UK, Denmark, France, Portugal and several Scandinavian countries. There are concerns that while introducing childhood vaccination would be beneficial to those who receive it, it could be harmful to others, such as older people at risk of shingles.
Fortunately, mounting evidence suggests that such harm is not occurring. What’s more, an analysis published today suggests that, overall, the vaccine does more good than harm. So, is it time for countries to become vaccine-resistant to chickenpox?
Chickenpox is caused by a highly contagious virus called varicella zoster. In the absence of vaccination, most people become infected in childhood and usually have a mild illness, the main symptom of which is an itchy, blistering rash.
In fact, the younger a person is when they hold it, the lighter their experience. Some families intentionally expose their children to others who are infected in order to “fake the disease”.
But the virus can sometimes cause severe symptoms – for example, if it triggers a bacterial infection – and can even be fatal, especially in people with weakened immune systems.
When the first chickenpox vaccine was developed three decades ago, there was a concern that while children who received it would benefit, some parents might not get their children vaccinated. A routine vaccination program would mean that population-level immunity would be relatively high, so those who missed out may not have encountered the virus until they were in their teens or older, most likely from childhood. The risk of serious complications increases compared to infection.
Another fear was the effect on older people. After infection with chickenpox, the virus’s DNA remains in nerve cells and it can reactivate in later life, causing the painful and debilitating symptoms of shingles. It is believed that chickenpox infection in children exposes adults to small doses of the virus, increasing their immunity and making them less likely to get shingles.
Despite concerns, the US began routinely offering the vaccine to children in 1995, with other countries later following suit. Those who stayed are now able to see results, which suggest getting vaccinated was the right decision.
Several studies over the years have shown that the U.S. Haven’t seen an increase in herpes cases, A UK study found that if adults are exposed to a child with chickenpox in their household, the reduction in their risk of shingles is smaller than before, with a decline of approx. 27 percent in 10 to 20 years,
Now, data from such studies has been plugged into a standard set of equations that predict the effects of vaccines on infection and disease rates. This has been used to model the effects over 50 years if children are routinely vaccinated in Denmark.
The researchers — which included scientists from Merck, the manufacturer of one of the vaccines, and Aarhus University Hospital in Denmark — found that shingles cases would increase by about 1 percent in the first few years after the introduction of vaccination, compared to 50 years. After that, if Denmark continues not to vaccinate, the total number of cases will be 9 percent less than expected.
They also found that the number of people of any age who die or need hospital treatment for chickenpox would be cut by more than 90 percent, countering the idea that more severe cases than unvaccinated people. There will be an increase, while older people will catch the virus. ,
Vaccination programs would also avoid some of the less obvious harm from this virus, including children missing school and parents taking time off work, says manjari pawaskar at Merck in Rahway, New Jersey. “It’s a significant caregiver burden,” she says.
Several countries, including the UK and Denmark, are now considering including the chickenpox vaccine in the routine childhood vaccines on offer. At this point in time, many such countries let people pay for the vaccine privately, but that means little. A spokesman for the UK Health Protection Agency says the UK’s vaccine advisory panel, the Joint Committee on Immunization and Immunization, will take any new data into account.
For adults who have experienced chickenpox as a mild illness, it may be tempting to dismiss the need to vaccinate against the condition. But one thing that the COVID-19 pandemic has shown is that even if a disease severely affects a small segment of the population, it can cause significant damage on a large scale across the country and fight against it. It is worth retaliating.
Perhaps it’s time for more countries to stop giving the chickenpox virus a free pass.