Why we should consider vaccinating even younger people in Wales against Covid-19

Dylan Jones, Lecturer in Biomedical Sciences at Bangor University

Cases of Covid-19 are now back at levels that were last seen in January but mercifully the number of deaths is nowhere near the levels we were seeing at the height of the second wave (three deaths in 24 hours recorded on Friday compared with the 40 or so earlier in the year). This reversal in mortality rates is thanks to the robust vaccination campaign here in Wales that has (as of the 29th of August) seen 83% of the eligible population receive two doses of vaccine.

For those of you with a head for numbers, you may be a bit perplexed why the number of double vaccinated individuals has gone down since last week (from 84% to 83%). The major cause for this is the welcome news that Wales will now be extending the routine vaccination to the 16–17-year-old age groups. As a result of this decision, an extra 81,365 individuals here in Wales will have access to a potentially lifesaving series of injections.

The decision to offer younger people access to the vaccines has, however, generated a degree of controversy amongst some members of the public. Some of the concerns range from the outlandish (vaccines will change the DNA of our young people) to well-meaning concerns on the rare adverse effects that can occur in a small proportion of patients (myocarditis or a swelling of the heart is commonly brought up).

Many also ask the question of why we should be vaccinating an age group that historically have not been exposed to the same Covid-19 mortality rates as other age groups. For the rest of this piece, I would like to explore why extending access to the vaccine could be a good thing for the young people of Wales and why we should potentially consider offering the vaccine to even younger individuals such as countries like Israel and the United States of America have been doing.

Transmission

The Covid vaccines have been shown to be effective at reducing transmission rates of the virus. A study by Public Health England earlier in the year showed that receiving a single dose of vaccine can make an individual between 38 and 49% less like to transmit the virus to another individual.

A question commonly asked is “why isn’t the vaccine 100% effective at stopping the virus?”. This is down to something known as sterilizing immunity. Some vaccines are much more effective at encouraging the body to produce an immune response that will destroy an invading pathogen stopping an individual from becoming symptomatic or spreading the disease. With the Covid vaccines currently in use they do not appear to induce such a strong sterilizing effect, and therefore we see reports of vaccinated individuals becoming infected and being able to transmit the virus.

As we have learned during this pandemic, cutting the chain of transmission is a key part in preventing further infections and this is key in preventing further deaths. By vaccinating as many people as possible we will significantly hamper the ability of this virus to spread particularly given many young people will soon be back in education which brings people together in very close contact within an indoor setting.

During the last year according to Public Health Wales 86% of Welsh schools have reported a case of Covid-19 with 8957 children testing positive for the virus (and a further 4989 cases in staff). This level of infection has seen classes being sent home to self-isolate, people have been receiving instruction via online learning and opportunities for play and socialise that are so important to childhood development being removed.

By combining a widespread vaccination campaign and targeted testing of symptomatic individuals we can hopefully reduce the disruption to childhood education and begin getting young people back to class. Indeed, here in Wales the change to the self-isolation rules (double vaccinated individuals no longer have to self-isolate following contact with a Covid-19 positive patient unless they begin to exhibit symptoms) at the start of August will offer a glimpse of hope for teachers concerned as to how they can begin to manage their classrooms come the new term.

Long Covid

Life is constantly evolving to better take advantage of its situation and evolution is driven by mutations in our genetic code. This is exactly what we have been seeing with all the Covid-19 variants over the last 20 months. Each variant is subtly different from the original strain that erupted from Wuhan, China in 2019 with each variant having slightly different characteristics. The delta variant for example is more contagious and potentially causes more severe illness in unvaccinated individuals than the original strain.

Because of the biology of the Covid virus, each time an individual becomes infected there is a chance that as the virus is duplicating in our cells it will gain a mutation that will lead to a whole new Covid variant. Unfortunately, we have no way of predicting when these variants will appear or even what type of characteristics, they will exhibit so the prudent thing to do is to minimize the number of infections to reduce the risk.

Long Covid is a long-term complication usually given as a persistence of symptoms for 28 days following a Covid infection and those who have long Covid report the persistence of symptoms (such as tiredness, joint pain, alteration to mood) for many weeks and in some case months. In adults long Covid is believed to occur in 10-15% of all those who have had Covid but is believed that the rate of long Covid occurring in children is lower at around 5%.

Whilst these percentages look small, given the large numbers who are/have been infected with the virus the absolute numbers who will develop long Covid will potentially be huge. To the individual, long Covid can be debilitating and can lead to individuals finding it difficult to work and function as normal. The impact this can have on physical and mental health will be significant let alone the wider financial and social impacts to the individual. From the perspective of children, a recent report found that almost a fifth of older children experienced “brain fog” with a slightly smaller proportion experiencing low mood.

Whilst evidence seems to suggest that most children with long Covid recover by eight weeks, this length of illness could be seriously detrimental to an individual’s educational attainment which could have life-long consequences.

Success

Is there any precedent to such a large-scale vaccination campaign of young people? Again, we tend to forget that we have been vaccinating children against disease for a long time with the age of modern childhood vaccination beginning in the middle of the 20th century.

Diphtheria, polio, and smallpox aren’t names that many readers will be familiar with and that is down the successes we have had in vaccinating against these diseases (indeed smallpox is now extinct in the wild due to vaccines). More recently we have had vaccines against meningococcus (one of the bacteria that causes meningitis) and the human papillomavirus (HPV, the major cause of cervical, penile, and anal cancer). Some of us may even carry the physical scars of the BCG vaccine which was helpful in combatting tuberculosis which was first used in 1953 in the UK and continued to be given to secondary school children until 2005.

We here in Wales and the wider UK have one of the lowest childhood mortality rates in the world and a key part of this is the robust childhood vaccination schedule we use. This is worth considering if, in the future, an additional entry will be made in this schedule for a Covid-19 shot.