Malta’s Superintendent for Public Health takes questions from Times of Malta readers.
I am an 86-year-old man. I need to travel by bus. How dangerous is this, especially with the increase in COVID-19 cases in the community? – Albert Said
It is essential that all persons, especially people of that age, make sure they are fully vaccinated and get the booster dose, as evidence is clear that vaccines are effective at preventing serious outcomes due to COVID-19, such as severe illness, hospitalisation and death.
However, additional protection is important for areas where there is more crowding, such as buses, in a situation with high community transmission. The risk can be reduced significantly by wearing a multi-layered mask and maintaining good hand hygiene.
Given the surge in cases all over Europe, will Malta be updating its dark red zones list? – Alexia Mejlak
The overall epidemiological situation in the EU/EEA was characterised by a high case notification rate and a low but slowly increasing death rate which is being driven mainly by the ongoing transmission of the Delta variant.
The picture varies considerably between countries. Increasing case notification rates and an overall epidemiological situation of high or very high concern are now observed in most of the EU/EEA member states.
From modelling studies, the European Centre for Disease Prevention and Control (ECDC) is predicting that Omicron is likely to be the dominant variant in the coming months. Ongoing assessment of the situation globally and in Europe is being conducted. Travel policy will continue to be guided by epidemiological assessments and through regular meetings of experts from EU member states.
What is the current treatment in hospitals of symptomatic COVID-19 people and has it changed from the beginning of the pandemic? – Torben Halvorsen
Hospitalised patients are given treatment based on the assessment of the clinical condition and authorised treatments available at the time. This includes monoclonal antibodies, dexamethasone, Remdesivir and oxygen and support care.
Ongoing advancements in treatments provide more support in the care of COVID-19 cases.
This was encouraged by Emer Cooke, chair of ICMRA and EMA’s executive director, who stated: “While vaccines remain the main weapon in our fight against the pandemic, we also need safe, effective and high-quality medicines to treat and prevent COVID-19, in all its manifestations and in all populations, including children and pregnant women.”
I have tested positive. How would I know if I was positive for Omicron? –Mary Camilleri
There are two types of tests which are used to test for current infection. The gold standard test is the nucleic acid amplification test or NAAT. This is a type of viral diagnostic test for SARS-CoV-2, the virus that causes COVID-19.
NAATs detecting genetic material (nucleic acids) have been used as a diagnostic tool for years. NAATs for SARS-CoV-2 specifically identify the RNA (ribonucleic acid) sequences that comprise the genetic material of the virus. The most commonly used type of NAAT is the reverse transcription polymerase chain reaction (RT-PCR).
The other type of tests available are the antigen tests. Antigen tests are commonly used in the diagnosis of respiratory pathogens, including influenza viruses and respiratory syncytial virus and are being also used for COVID-19. Antigen tests are immunoassays that detect the presence of a specific viral antigen, which implies current viral infection.
In order to confirm the variants, genomic sequencing is required on the positive sample. This is used for surveillance purposes to be able to identify new emerging variants, describe the epidemiology of the variants and plan responses accordingly.
We are being encouraged to take the booster vaccine. Do we know if this will work on the new Omicron variant? – Jesmond Xuereb
A report by the UK Health Security Agency presented data from recent estimates of vaccine effectiveness on prevalent variants. The vaccine effectiveness against symptomatic infection is significantly lower against Omicron infection compared to Delta infection.
However, they have seen that there is a moderate to high vaccine effectiveness against symptomatic infection of 70 to 75 per cent in the early period after a booster dose.
Similar observations were made last week by the Israeli and French authorities, both asserting that the risk of infection among those having had three doses is quite low.
Data on vaccine effectiveness against severe disease with Omicron is expected to take a few more weeks, however, as like with previous variants, vaccine effectiveness against severe disease, including hospitalisation and death, has been higher than effectiveness against mild disease.
Pfizer-BioNTech have published information from preliminary laboratory studies which show that a primary schedule with two doses and a third dose can neutralise the Omicron variant (B.1.1.529 lineage) in comparison to only two doses, which show significantly reduced neutralisation titres.
The third dose increases the neutralising antibody titres by 25-fold compared to two doses against Omicron variant. Since 80 per cent of the epitopes in the spike protein recognised by CD8+ T cells are not affected by the mutations in the Omicorn variant, the two doses may still induce protection against severe disease.
Alas, there appears to be a higher risk of reinfection for those with a history of previous COVID-19 infection and no vaccination, as warned by the WHO late last week. Preliminary data from South Africa seems to suggest the risk of reinfection may be three times higher that with other variants. Once again, we will know more once more data is available. Hence ensuring population vaccination with booster doses, coupled with non-pharmaceutical measures, remains the best course of action to prevent the spread of COVID-19.
As many countries are grappling with the new variant, is the spread due to more people meeting or is it because this new variant does spread faster? – Miriam Vella
The best setting to evaluate transmission is from studies in households. A cohort analysis was conducted in the UK to estimate the odds of household transmission for Omicron index cases compared with Delta index cases.
This study has showed that there is a higher risk of transmission to contacts from an Omicron index case when compared to Delta index cases. These preliminary studies have shown that the risk of transmission from an Omicron index case compared to a Delta index case is 3.2 times higher.
Have any questions to ask the superintendent? Send an e-mail to askcharmaine@timesofmalta.com.