© AP Photo/Bernat ArmangueA woman in Gibraltar receives a second dose of the Pfizer-BioNTech vaccine - AP Photo/Bernat Armangue
The Pfizer-BioNTech vaccine was able to neutralise the highly infectious Brazilian P.1 variant in the laboratory, raising hopes that existing jabs will offer some protection against concerning new strains of Covid-19.
Scientists tested the blood of 15 people who had received the Pfizer jab against the virus which was engineered to include the mutations found in the P.1 variant. This was first identified in Manaus, a city in the heart of the Brazilian Amazon hit by two devastating waves of Covid-19.
According to a letter published in the New England Journal of Medicine, the vaccine offered "roughly equivalent" levels of protection against both P.1 and a less infectious strain of the virus that was circulating early last year.
Though experts have cautioned that these results need to be validated in "real life", there is growing optimism that existing coronavirus vaccines will provide at least some protection against highly contagious new variants.
Last week, Reuters reported that the AstraZeneca-Oxford vaccine is also effective against P.1, citing data from Brazil's Fiocruz biomedical institute.
"I think it does bode well for real life data," Danny Altman, a professor of immunology at Imperial College London, told the Telegraph. "This is all starting to fall into place now - variants such as P.1, among others, are certainly good at evading the response of some neutralising antibodies [which protect against Covid-19].
"But when we see a good immune response to Pfizer or Moderna - both of which induce astronomically high antibody levels, even when knocked down a little - the response is still firmly in the protective range."
Gallery: The biggest medical advances of the 2010s (Espresso)
Prof Beate Kampmann, director of The Vaccine Centre at the London School of Hygiene and Tropical Medicine added: "It's reassuring to see this comprehensive assessment of vaccine-induced neutralising antibody against a variety of variants.
"However, we cannot simply extrapolate from the immune responses induced by the Pfizer vaccine to other vaccines. work is already going on to 'tweak' the vaccines for the boosters that are likely to be necessary with all Covid-19 vaccines."
The NEJM study, conducted by scientists at the University of Texas, also tested the Pfizer jab against virus modified to include spike protein mutations found in the variants detected in Kent and South Africa - B.1.1.7 and 501Y.V2.
It is the spike protein that the virus latches onto to enter human cells, and the majority of vaccines target this part of the virus.
Like P.1, the Pfizer shot generated high levels of neutralising antibodies when presented with B.1.1.7. However there was "robust but lower" activity against 501Y.V2.
Previous studies have also suggested that the Pfizer jab may be slightly less effective against the variant first found in South Africa.
The company has said it believes the jab still protects against disease, but has plans to test whether a third booster dose or a slightly tweaked vaccine may generate higher levels of neutralising antibodies.
There are some concerns that other vaccines may also provide less protection against 501Y.V2. Last month South Africa stopped using the AstraZeneca-Oxford jab after data suggested it had little impact on mild infections caused by the variant.
Protect yourself and your family by learning more about Global Health Security
Sign up to the Front Page newsletter for free: Your essential guide to the day's agenda from The Telegraph - direct to your inbox seven days a week.