A new study analyzes the impact of this decision on the epidemiological situation in two European countries (Italy and France). Even if the interruption is only a few days, the consequences will not be alleviated. Death and public confidence in the vaccine will continue to feel the consequences.
In April 2021, the European Medicines Agency (EMA) Confirm Vaxzevria Oxford/AstraZeneca vaccine The disease against COVID-19 may be related to the rare thrombocytopenia cases reported on the African continent.
Following this communication, despite the EMA’s insistence that some countries in the European Union (such as Spain) have decided to stop the administration of the drug. benefit The proportion of vaccinations is much higher than Possible damage May cause this very rare side effect.
From this break, a team of London Math Lab The consequences of this decision on the health of the population and the pandemic situation have been discussed.For this, they used Epidemiological model They used SEIR to estimate the excess mortality caused by covid-19 and estimated two scenarios: France and Italy.The results are published in the latest issue of confusion.
The main conclusion of the model is that even in the worst-case scenario, the frequency and severity of side effects of the drug, the additional mortality caused by the interruption of this vaccine far exceeds the death caused by thrombosis.
The change in excess mortality caused by the suspension of the Oxford/AstraZeneca vaccine is a function of the number of days of interruption. / Davide Faranda, Tommaso Alberti, Maxence Arutkin, Valerio Lembo and Valerio Lucarini
Davide FarandaThe lead author of the study explained to SINC that the SEIR model assumes that the population can be divided into four categories: those who can be infected with the virus (susceptible), those with asymptomatic infection (exposed people), and those with symptoms of infection (infected ) And uninfected people. Those who were infected recovered. He said: “In the last compartment, we not only counted the number of people who had overcome the disease, but also the dead and those who were vaccinated.”
Therefore, the model “moves” the population from one compartment to another according to the epidemiological situation, the time it takes to spread, show symptoms and cure the virus.Through these exercises, we can estimate Excess mortality Used for covid-19 and the side effects associated with these vaccines.
Due to the large uncertainty of these thrombosis and thrombocytopenia, it is not yet clear which populations are the most vulnerable or their actual incidence in the vaccinated population. The researchers calculated The worst situation They believe that these side effects will be higher than the currently reported mortality rate.
“Our work shows that stopping the use of AstraZeneca’s vaccination within three days without replacing the vaccine with other options can lead to 260 Additional death Flanda stated that there are 130 in France and Italy”. The reason for this difference is that as of March 15, 2021, the epidemiology of the two countries and the different reproduction numbers or R0.
What happens when the vaccination effort is doubled
The model explains that if Vaxzevria vaccination is resumed at the same rate as before the drug withdrawal, Significantly high mortality: People who have not been vaccinated during this period may be infected and contaminate other people.
In addition, although with Double dose In the same number of days of the pause, the excessively high mortality rate will continue in the next few days, although the figure is lower than the standard restart. The lead researcher replied: “This is a clear result of the nonlinear effects of epidemiological dynamics.”
If the use of Oxford/AstraZeneca is resumed at normal and twice the rate, the mortality rate is too high. / Davide Faranda, Tommaso Alberti, Maxence Arutkin, Valerio Lembo and Valerio Lucarini
According to the authors, this suggests that the effects of interruptions are difficult to offset and will continue over time. In addition, public confidence in vaccines will decline, which directly affects the use of vaccines. Public health But this study was not collected.
Faranda told SINC that although this mathematical explanation has “robust results” and is useful for explaining the effect of public health decision-making, it has found some “limitation powerful”.
He pointed out that the first one is the model assumption Only one vaccine Have Oxford/AstraZeneca features and “forget” all other approved options in Europe. At the same time, he explained that the discontinuation of this drug cannot be replaced by another vaccine against covid-19.
Finally, the model does not contain Age is a risk factorEMA is evaluating the side effects associated with the vaccine.
Flandre, D. Wait. “The interruption of vaccination policy can greatly spread SARS-CoV-2 and increase the mortality rate of COVID-19 disease: AstraZeneca cases in France and Italy.” confusion (2021). DOI: 10.1063 / 5.0050887