A study by the UK Health Insurance Agency (UKHSA) raises the prospect of a fourth dose in the United Kingdom, which shows that the Omicron variant is milder than the Delta, but also that the protection against Omicron infection offered by the booster dose is gradually declining. .
The largest study of real data in the UK to date, published on Thursday, showed that protection against simple symptomatic infection from the booster dose is reduced by 15-20% ten weeks after vaccination.
Those who initially take two doses of the AstraZeneca vaccine and then a booster dose with the Pfizer or Moderna formulation get 60% protection against Omicron two to four weeks after the third dose. After ten weeks, however, this protection is convinced at 35% for the Pfizer vaccine and 45% for the Moderna vaccine.
Those who have taken three doses of Pfizer have 70% protection against a simple infection, which drops to 45% after ten weeks.
The best protection comes from combining two doses of Pfizer with a third dose of Moderna, as it stays at 75% for nine weeks.
However, scientists estimate that protection against serious infection and hospitalization lasts longer.
According to the Times, the Joint Vaccination and Immunization Committee is "monitoring the situation very closely", while a government source states that the vaccination planning is "flexible" and could include a fourth dose. "It is something for which there is obviously a possibility and for which we are preparing, but our priority is to complete the current program of aid installments", added the source of the newspaper.
The same UKHSA study showed that the chance of hospitalization for Omicron carriers is between 50% and 70% lower than for those with Delta variant.
The probability that they will need to go to the emergency room for examination is also 31-45% lower.
However, the SAGE scientific return advising the Government estimated in a meeting on Sunday that Omicron may have to be 90% milder than Delta to avoid an unmanageable pressure on the NHS health system from the increased hospitalizations. This assessment is based on the scenario of no further action and the assumption that citizens will not show caution with practical changes in their behavior.
It is noted that on Thursday a new record of coronavirus cases was recorded in the country with almost 120.000, while the Office for National Statistics estimated that in the week of December 9-16 there were 1,4 million COVID carriers in the United Kingdom.
The UKHSA also found that Omicron caused more infections than Delta. 9,5% of all Omicron cases are recurrence cases.
Of the 132 patients of the new variant by December 20, 17 had taken the third dose, 74 had taken two doses and 27 were unvaccinated.