From what we know so far, should we be concerned about the new variant? – Mary Mamo

A SARS-CoV-2 virus of the Pango lineage B.1.1.529 with a high number of S-gene mutations was detected in Botswana and later in South Africa. A number of travel-related cases have been detected in various countries including Europe and some in country transmission.

This variant, on sequencing, has 30 changes detected in the spike protein and in the receptor binding domain. Since this virus is so divergent from previous strains, it raises concerns of potentially increased transmissibility and some degree of immune escape as compared to the Delta variant; although this is yet unconfirmed by scientific evidence. 

In view of significant uncertainties regarding the characteristics of this variant, a precautionary approach is being strongly advised by ECDC with reinforcement of the measures of physical distancing, hand hygiene, increased ventilation and use of face masks.

Encouraging primary vaccination and also booster doses in those who have completed vaccination is critical. Genomic surveillance by testing and sequencing is also crucial in order to identify early any epidemiological trends locally enabling rapid public health action to be taken.

As a precautionary measure, through LN465, since November 28, a travel ban has been instituted for all persons returning from South Africa and Namibia as well as other neighbouring countries already under a travel ban and termed ‘dark red’.

Will children be given one dose of the Pfizer vaccine or two? Why? – Angela Caruana

On November 25, the European Medical Agency recommended approval of the COVID-19 vaccine Comirnaty (Pfizer/BioNTech) for children aged five to 11. This vaccine is already approved for use in adults and children aged 12 and above.

In children from five to 11 years of age, the dose of Comirnaty will be one-third of that used in people aged 12 and above and it will be produced in special packaging indicated for this age group. As in the older age group, this is given as two injections, three weeks apart.

A main study in children aged five to 11 showed that the immune response to Comirnaty given at a third of the adult dose in this age group was comparable to that seen with the higher dose in adults.

The most common side effects in children aged 5 to 11 are similar to those in people aged 12 and above. They include pain at the injection site, tiredness, headache, redness and swelling at the site of injection, muscle pain and chills. These effects are usually mild or moderate and improve within a few days of vaccination.

Although COVID infection in children tends to be mild, there is high transmissibility of the virus among children. This is thought to be due to the fact that when a high percentage of the adult population is vaccinated the virus would tend to spread more in the unvaccinated pool of children. Although symptoms are usually mild in children, COVID infection in a child will lead to isolation of the child and family, school disruption and,  consequently, causes stress and anxiety to both the child and family.

Once the vaccine is available in Malta, parents are urged to vaccinate their children to halt the spread of the disease, especially now that activities are moving indoors as well as because of the presence of new variants about which we still know very little.

In less than a year, we would have had three doses of the vaccine. Will we have to continue taking the vaccine as regularly in the future? – Amy Cini

It is well known that when using inactivated vaccines – vaccines that do not use a live virus to trigger an immune response – multiple doses are needed.

A priming course is followed at least six months later with an additional jab that helps the immune response to mature. Many vaccines given in childhood, apart from COVID-19 vaccines are administered in a three or four-dose series, with a gap of several months between the first course and the last shot.

The requirement of an additional booster will depend on what happens to the antibody level after this third dose. Studies are showing very hopeful results that the antibodies would persist for a long time.

However, if the virus changes considerably, like with influenza we need to adjust the vaccine to the mutations of the virus.