A study analyzed data from 44 million inoculated people and found that their protection against a serious disease decreases after three months for those vaccinated with AstraZeneca.
(UK – The Lancet) – According to a study that highlights the need for boosters, protection against serious disease after two doses of AstraZeneca’s COVID-19 vaccine begins to wane about three months after the second dose. Researchers analyzed data from 2 million people in Scotland and 42 million people in Brazil. They assessed the risk of severe cases of COVID, including hospitalizations and deaths, three months after the second dose.
They did not analyze Astra’s vaccine against the fast-spreading omicron variant, which was not circulating at the time. “We found decreasing vaccine protection against hospital admissions and deaths from COVID-19 in both Scotland and Brazil,” the researchers detailed in the study, published in The Lancet.
They noted that consideration should be given to providing booster doses of the vaccine for people who have received initial treatment with the Astra vaccine, developed in conjunction with the University of Oxford. The UK, which relied on AstraZeneca’s vaccine for primary immunization of people over the age of 40, is already rolling out a rapid deployment of messenger RNA booster vaccines from Pfizer and its partner BioNTech, or Moderna.
The prime minister, Boris Johnson, hopes that boosting population immunity can help curb the spread of omicron and ease the growing pressure on the country’s National Health Service.
A growing body of evidence suggests that it will take three courses of the world’s most widely used COVID-19 vaccines to generate sufficient antibodies against the omicron variant. However, antibodies are only one part of a person’s immune defense, and T cells also play a role, making it difficult to assess the efficacy of the current generation of omicron vaccines.
AstraZeneca CEO Pascal Soriot commented last month that the company’s vaccine might be the reason the UK was doing better with COVID hospitalizations than Europe at the time. He suggested that the slower developing T-cell response could mean that the vaccine provided longer-lasting immunity in the elderly. However, he noted that more data were needed, a view shared by the scientists.
Penny Ward, professor of pharmaceutical medicine at King’s College London, said that while the paper gives a “rather alarming impression at first glance, it also shows that there is sustained effectiveness of the vaccine in preventing hospitalization and death from COVID of at least 50 percent throughout the study.”
She added that the data reiterated the importance of people “getting out and getting their booster as quickly as possible.”
The Yucatan Times