St George’s Day – Vaccine trial and Children

Vaccine Development

Today is St George’s Day, the patron Saint of England, and some regions in Portugal and Spain (Aragon and Catalonia). Interestingly, Portugal has only 850 deaths as of today (worldometres.info) compared to the high numbers in UK and Spain.

Also today marks the start of the  first European coronavirus vaccine trial with two patients injected in Oxford. Lets hope the spirit of St George watches over them and that the full trial is successful against all the odds.

Children and Covid-19

As I wrote on the Home page of this Blog, the mortality profile of Covid-19 is unusual from a virological point of view because, in contrast to the influenza viruses, children are mostly spared and men are affected about twice as often as women. In the major pandemics and plagues over the centuries, children have often been early victims, Indeed, the first British victims of the 1918 “Spanish flu” pandemic were identified as 8 children from a Lanarkshire orphanage who were buried in a mass grave.

A new nursery rhyme started to be heard in playgrounds across Britain, sung by skipping schoolchildren: “I had a bird, its name was Enza. I opened the door and in-flu-enza”.

As well as the viciousness of this virus, there was another aspect to this flu strain which made it stand out, baffling the doctors of the day. While influenza generally proves fatal for the young, sick and elderly, the 1918 variety seemed to affect those who were fit and healthy. The highest death rate was among those aged 20 to 34 – the same generation that had just lost so many lives in the trenches.

Source – http://www.express.co.uk/news/uk/955767/spanish-flu…

Scientists now believe that those with the strongest immune systems were the ones to die because those immune systems went into overdrive, producing an overreaction to the virus which led to death. There is evidence that this also applies to coronavirus.

Going back to child mortality in the current coronavirus pandemic, this corresponds to the profile of natural mortality, which is close to zero for children and almost twice as high for 75+ year-old men as for women of the same age.

Article in The Lancet

The absence of paediatric patients with COVID-19 has perplexed clinicians, epidemiologists, and scientists. Case definitions and management strategies for children are absent because of the limited number of paediatric patients with COVID-19. 

Because of this, one would think that this apparent immunity would be a major line of research, but articles on children and Covid-19 are few and far between.

This article outlines an important study in China which indicates that infants and children can be infected by Covid-19.I wont go into the detailed results, but  the most important finding to come from the present analysis is the clear evidence that children are susceptible to SARS-CoV-2 infection, but frequently do not have notable disease.

This raises the possibility that children could be facilitators of viral transmission. If children are important in viral transmission and amplification, social and public health policies (eg, avoiding interaction with elderly people) could be established to slow transmission and protect vulnerable populations. There is an urgent need to for further investigation of the role children have in the chain of transmission.

Full article source – https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30236-X/fulltext

Case of the French boy

An investigation by Public Health France found that the a French nine-year-old boy with Covid-19 did not pass it on to either of his siblings nor anyone else, despite coming into contact with 172 people, all of whom were quarantined as a precaution, and having lessons at three separate ski schools.

A report on the investigation published in Clinical Infectious Diseases describes how tests revealed the boy to be infected with Sars-Cov-2, the virus that causes Covid-19, and also influenza and a common cold virus. While both of his siblings caught the latter infections, neither picked up the coronavirus.

The boy had only mild symptoms and when tested was found to have levels of virus that were barely detectable. The low level of infection is thought to explain why he did not infect other people.

The researchers believe that since children typically have only mild symptoms, they may transmit the virus far less than infected adults. “Children might not be an important source of transmissions of this novel virus,” they write.

Why children generally escape the worst of the virus is not well understood, but many scientists suspect that their immune response is somehow able to clear the infections more rapidly than older adults, who tend to be hit much harder by the illness.

The report comes after researchers at UCL concluded this month that school closures would likely have only a small effect on the spread of the virus, and that this should be weighed up against the profound social and economic costs. Dozens of countries have closed their schools to slow the transmission of coronavirus, though the restrictions have been brought in to avoid the social gatherings that happen around schools as well as limiting spread of the virus within them.

The role of children in spreading the virus remains one of the key mysteries of the coronavirus pandemic and the question of whether those who develop few if any symptoms are carriers is still being debated. While the proportion of children who experience severe illness is tiny compared with that of older people, some have fallen seriously ill and died from the infection.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: