The coronavirus has entered our lives for good as we have already spent a year living with it.
According to pandemic experts last year in the US were recorded approximately 30 millions of COVID-19 infections and more 500.000 deaths.
Until today, as broadcast by the Athenian News Agency, have become approx 80 millions of vaccine doses in the US, and experts say the number of new cases and deaths will continue to fall in the coming days. However, Questions are raised by both clinicians and citizens in general, on vaccination and the future of the pandemic.
The Doctors of the Therapeutic Clinic of the Medical School of the National and Kapodistrian University of Athens, Theodora Psaltopoulou, Giannis Danasis, Panos Malandrakis and Thanos Dimopoulos summarize the data as published in the prestigious JAMA magazine, answering the most frequently asked questions of the citizens.
- Which vaccine is best and how it will be administered;
Two mRNA vaccines have currently been approved by the FDA (of Pfizer and Moderna) and an adenovirus vector vaccine (Janssen/Johnson & Johnson), and the Astrazeneca vaccine from the European Medicines Agency. These vaccines have been shown to be effective in preventing severe COVID-19 disease and mortality., reducing transmissibility.
Janssen vaccine is the first FDA-approved adenovirus vaccine, which uses Ad26 virus to carry the genetic material of SARS-CoV-2 virus spike protein. Due to the fact that it is administered in a single dose, this makes it easier to plan mass vaccination of the population. In terms of vaccine efficacy the two mRNA vaccines have similar efficacy in preventing 95% about cases of COVID-19 symptomatic disease and 100% almost deaths after two doses. Nevertheless, None of these vaccines were tested when the newest coronavirus strains appeared., such as B.1.1.7 and B.1.135.
The Janssen vaccine was 66% effective against moderate disease, 85% against severe disease and 100% versus mortality from COVID-19 infection.
The answer to the question of which vaccine should be given to the population is that all vaccines are safe and effective and all citizens should be vaccinated as soon as possible with whatever vaccine is available..
- They also protect the vaccines against the transmission of the coronavirus;
The efficacy of vaccines against virus transmission is difficult to demonstrate because many factors can affect the spread of coronavirus.
The first data from phase studies 3 show a reduction in asymptomatic disease after vaccination, while in Israel already the first data show a declining trend in the number of new infections after mass vaccination of the population.
- What is the best way to deal with citizens' reluctance to get vaccinated?;
Many factors contribute to cultivating a climate of controversy over the vaccine, such as the mandatory nature of the vaccine, their conjunctural identification with side effects, ignorance about diseases prevented by vaccination, and citizens' distrust of pharmaceutical companies and political leadership. In a survey 1676 American citizens in December 2020 the 27% were hesitant about vaccination.
In order to curb this insecurity of the citizens, the technology behind these vaccines must first be understood (mRNA and with adenovirus vector), to address any doubts about their safety (do not affect the genetic material of the vaccinated), and curb conspiracy theories and misinformation.
- How safe people are after the vaccination is completed;
The CDC (Center for Disease Control and Prevention) announced that 14 days after the second dose of the vaccine for the next three months one does not need to be quarantined after being exposed to a positive case.
Although it is probably safe to contact someone who has completed the vaccination, and vaccinated people should follow precautions such as using a mask, keeping distances and good indoor ventilation, while multi-person gatherings should be avoided for the time being.
- How effective are existing vaccines for new strains of the virus;
The more the SARS-CoV-2 virus spreads, the more often new mutations and new strains of the virus will appear.. Data to date suggest that the Moderna vaccine is effective against strain B.1.1.7 (which first appeared in the United Kingdom), but is less effective against strain B.1.351 (South African strain).
Data from clinical phase trials 3 for the Novavax vaccine carried out in the United Kingdom dominated by strain B.1.1.7, showed efficiency in percentage 89%, while in South Africa where the B.1.351 strain predominates the effectiveness was in 60%. Data from Israel show that the Pfizer vaccine is effective in the population where the predominant strain is B.1.1.7.
- What is the gap between the doses; Vaccines can be mixed;
Given the limited amount of vaccines worldwide, some have suggested delaying the second dose in order to vaccinate a larger portion of the population. In the United Kingdom the second dose of Pfizer vaccine was delayed by up to 12 weeks, instead of the predetermined interval of 21 days.
The CDC has announced that the margin between the two installments may be up to 6 weeks, as the large time gap between doses leaves people with insufficient immunity for a longer period of time and can potentially contribute to the emergence of new strains. There are no data on the use of a different vaccine for the second dose than that given in the first dose., however it is not recommended by the CDC except in very special circumstances. Because the combination of different vaccines can boost immunity to the virus, Clinical studies are currently being conducted to substantiate this claim.
- What happens if someone takes only one dose;
In people who already have COVID-19 infection, one dose of the vaccine has been shown to lead to an immune response similar to those who received both doses of the vaccine without a history of infection.. However, this presupposes the measurement of antibodies before the first vaccination and on the other hand raises questions among scientists as the possible insufficient immunity can lead to the emergence of new strains. Until there is more data, the recommendation remains for two doses of vaccine in mRNA vaccines.
- How long will the immunity offered by the vaccines last?;
SARS-CoV-2 vaccines offer immunity both by producing antibodies and by stimulating T cellular memory immunity. Although the duration of the immunity that the vaccines will provide is not known, Repeated doses may be needed in the future to both boost immunity and protect against younger strains.
- COVID-19 infection will become endemic;
It is possible that in the coming months as the mass vaccination progresses, the virus will disappear from some parts of the world, but will continue to exist in others. Seasonal outbreaks of the virus are likely to occur in the future, especially in the winter months.