one astrazeneca shot may also cut transmission

the preliminary data , still under review in the lancet, looked at trials in the u.k., brazil and south africa. about three weeks after the first jab, one dose of the two-shot regime offered 76 per cent efficacy for up to three months. based on the new university of oxford research, the preprint notes that “a second dose given after a 3 month period is an effective strategy for reducing disease, and may be the optimal for rollout of a pandemic vaccine when supplies are limited in the short term.”

sir mene pangalos, executive vice president biopharmaceuticals r&d at astrazeneca, said in a news release , that extending the dosing interval “enables more people to be vaccinated upfront.”

in december, the world health organization (who)  had warned that while vaccines may protect individuals from serious illness, those who receive the shots may still spread it.“i don’t believe we have the evidence on any of the vaccines to be confident that it’s going to prevent people from actually getting the infection and therefore being able to pass it on,” dr. soumya swaminathan, chief scientist at the who, said in media briefing.

the data is still fresh and requires more review. the optimism over delaying doses might not necessarily translate to other covid vaccines. a study by mathematicians and epidemiologists  suggests delaying the second shot of the pfizer vaccine by up to twelve weeks may have more risks as the first dose is less effective than the follow-up, though it didn’t find the same issue with the moderna shot. in late 2020, the u.k. decided to delay the second doses of its approved vaccines, including the astrazeneca jab, from three weeks to twelve, in spite of concerns.

on twitter, the u.k.’s secretary of state for health and social care mike hancock said the oxford research news was “superb.”

“this publication about the oxford vaccine should give everyone confidence that this jab works not only to keep you safe, but also to stop you from passing on the disease to others,” he said, in a short video.

vaccines are our way out.

oxford vaccine protects against covid and helps reduce the spread. pic.twitter.com/7ccmylrluw

— matt hancock (@matthancock) february 3, 2021

“while this would be extremely welcome news, we do need more data before this can be confirmed and so it’s important that we all still continue to follow social distancing guidance after we have been vaccinated,” said dr. doug brown, chief executive of the british society for immunology, in the new york times .

health canada, which has approved the pfizer and moderna vaccines, is currently reviewing the astrazeneca vaccine. canada has ordered 20 million doses and approval is expected in mid-february.

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one astrazeneca shot may also cut transmission

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