Indispensable Covid booster to back up Oxford / AstraZeneca jabs, new research shows

A new study highlighting the importance of the booster program shows that the protection provided by two doses of Oxford / AstraZeneca coronavirus shots, including those for severe illness, diminishes three months after the second shot. start.

The researchers analyzed data from 2 million people in Scotland and 42 million people in Brazil who were vaccinated twice. Their findings are New peer-reviewed paper With a lancet late Monday. During the study, the Omicron mutant was not circulating.

“We found that the vaccine protection was weakened. [the vaccine] For Covid-19 hospitalizations and deaths in both Scotland and Brazil, this became apparent within three months of the second vaccination, “they write. “You should consider providing additional vaccine doses to those who receive it. [the vaccine].. “

Researchers were able to compare data from Scotland and Brazil. This is because similar three-month intervals were used between doses, and people at highest risk of severe illness and healthcare professionals prioritized vaccination at both locations.

During the study, viral variants (Scottish Delta, Brazilian Gamma) were circulating, weakening vaccine protection and “probably” contributing to reduced efficacy.

The UK, where many were vaccinated with the AstraZeneca vaccine earlier this year, has moved to provide mRNA booster shots to all adults to counter the rapidly expanding Omicron variant.

Other wealthy countries are stepping up booster programs to limit the spread of tensions. Early preliminary evidence suggests that the two-shot course of widely used vaccines produces antibodies against Omicron in lower doses than previous variants, but how this leads to efficacy. Not yet clear.

The head of the European drug regulator said: It will take some time The Financial Times reported on Monday to reach an agreement on whether shots targeting Omicron would be needed.

Scientists hope that the two shots will continue to protect against serious illness, as immunity is not just a function of the number of antibodies. However, some experts who were not involved in the study expressed concern that this could change the concept.

Peter English, a retired infectious disease management consultant, has so far made the general assumption that protection against serious illnesses and, for example, the more serious consequences of T cells, will last “probably years”. Said there was.

“This paper casts doubt on these assumptions,” said English. “This shows that prevention for severe illness gradually diminishes over time, and the likelihood of severe illness is about five times higher after just a few months than immediately after vaccination. “

“I’m very worried about this,” he said. “In the short term, it emphasizes the need for additional doses, and in the medium to long term, it raises questions about how effectively current-generation vaccines can prevent future illnesses.”

Another outside expert, Visiting Professor of Pharmaceutical Medicine at King’s College London, said Pennyward, “sustainable vaccine efficacy” to prevent at least 50% of Covid hospitalizations and deaths throughout the follow-up period. Said that there is still. However, she agreed that booster shots were needed to give a high level of protection.

Aziz Seek, author of the study and director of the Asher Institute at the University of Edinburgh, said by identifying when people who received the AstraZeneca vaccine first began to weaken: Protection is maintained. “

“If you qualify as a booster and don’t have one yet, it’s highly recommended to book now,” he said.

Pascal Soriot, Chief Executive Officer of AstraZeneca I had last month It was suggested that the use of vaccines in the elderly may help avoid serious illnesses in the elderly for a longer period of time. But he said there was no evidence and more data was needed.

Oxford and AstraZeneca did not respond to requests for comment.