Promising results.
A single dose of the Oxford/AstraZeneca vaccine provides protection from Covid-19 for at least three months and cuts transmission of the virus by 67%, new research has said.
It's important to note, these findings are preliminary and are still under review at
The Lancet, but they showed the vaccine remained effective while people waited for a second dose and reduced transmission.
Analysis of data from three trials showed the first shot reduced transmission of the virus by 67%, while it also provided an average of 76% protection against symptomatic infections from three weeks until 90 days.
This means that if the results stand up to scrutiny, protection is not reduced in the three months between the first and second dose of the vaccine.
"The data indicates that [the vaccine] may have a substantial impact on transmission by reducing the number of infected individuals in the population," the report said.
The impact of a vaccine on transmission is seen as key. If a vaccine stops you getting severely ill, but you can still catch and pass on the virus, then the entire population will need to be vaccinated in order to be protected.
But if a vaccine can stop an individual catching and spreading the virus, it will have a far greater impact as it indirectly protects others from catching the virus.
Prior to this study, little was known about the effectiveness of Covid-19 vaccines at preventing transmission and still less is known about the impact of spacing out the two shots of the Pfizer vaccine.
