Boosters for those with weak immune systems backed by UK study
Immunocompromised patients had weaker immune responses after two doses of Covid vaccine than the general population, according to a UK study that supports the case for booster shots for vulnerable people.
About 40% of 600 people with conditions like cancer and arthritis, whose treatments can interfere with immunity, had insufficient responses to standard vaccine regimens, according to the study published Tuesday in preprint form by the The Lancet medical journal.
Countries including the US have begun rolling out third shots for people whose immune systems are weakened either by disease or immune-blunting therapies. The US also released plans last week to give extra shots to people who’ve already received full immunisations, a notion opposed by some humanitarian and global health groups, including the World Health Organization, citing the lack of supply for many poor countries.
Some doctors and observers have pointed to a lack of evidence that extra doses increase protection significantly. But US regulators have already cleared third doses for people with severely compromised immune systems.
The US Food and Drug Administration and vaccine advisers to the Centres for Disease Control and Prevention are now considering the safety and effectiveness of third doses for the general population. The CDC’s Advisory Committee on Immunization Practices has scheduled a two-day meeting starting on Monday where booster shots will be discussed.
The findings of the UK study, called Octave, don’t give solid answers about Covid vaccines’ effectiveness in protecting immuncompromised patients, the authors said. “There is no agreed clinical cut off to measure Covid-19 vaccination response,” they said.
However, the results indicate that even partial protection from Covid-19 “may be clinically beneficial” said Iain McInnes, head of the College of Medical, Veterinary and Life Sciences at University of Glasgow, and leader of the study.
The study, conducted by researchers drawn from various UK universities looked across a number of patient groups at responses to standard vaccinations. Patients being treated for vasculitis, an inflammation of the blood vessels, had the lowest level of antibody response, the study said.
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