Pfizer and Moderna's Covid vaccines are both effective against the troublesome Lambda variant, scientists believe.
The mutant strain has now been spotted in 31 countries — and some doctors fear it is more transmissible than any existing versions.
But in a glimmer of hope, academics in New York say data suggests the variant is still susceptible to vaccines.
New York University Grossman School of Medicine researchers found antibodies triggered by MRNA jabs still naturalised the Lambda variant in laboratory studies.
It is not proof the jabs definitely work in thwarting the strain — but the scientists are confident.
Both Pfizer's and Moderna's vaccines are based on mRNA technology, which had never been used to make jabs until the Covid pandemic.
The mutant strain caught the attention of World Health Organization bosses after it was spotted in the UK, US and Germany.
Thought to have originated in Peru last summer, it quickly spiralled and now makes up 80 per cent of the South American country's cases.
Doctors monitoring its growth fear it spreads easier than other strains, including the Indian version that has caused havoc across the world.
But coronavirus-tracking scientists are puzzled about the true transmissibility of the variant, given it was first spotted in Britain and February and has yet to take off.
They have yet to uncover any proof the variant is actually any more contagious than existing strains, including Delta or 'Delta Plus'. Experts told MailOnline the variant is no reason to cancel or delay Freedom Day in the UK on July 19.
Others also insist there is no evidence to suggest it is deadlier, despite some doctors linking its spread to Peru having the world's worst Covid mortality rate.
The new study, published in a preprint on BioRxiv, offers more hope the variant may not be any more dangerous than other strains already circulating.
Researchers tested samples of the Lambda variant against vaccine-elicited antibodies and ones triggered by powerful drugs — the experimental therapy given to President Donald Trump during his hospitalisation with Covid last year.
It showed while the variant 'showed a partial resistance' to the antibodies created by the vaccines, the resistance 'is not likely to cause a significant loss of protection against infection'.
Pfizer and Moderna's Covid vaccines are effective against the Lambda variant, which has now been spotted in 31 countries, a study by the New York University Grossman School of Medicine has shown
The New York University study authors wrote: 'The results suggest that the vaccines in current use will remain protective against the lambda variant and that monoclonal antibody therapy will remain effective.
'The findings highlight the importance of wide-spread adoption of vaccination which will protect individuals from disease, decrease virus spread and slow the emergence of novel variants.'
Australia became the latest country to detect Lambda, it was revealed today. But the case also dates back several months.
The variant was detected in a traveller stuck in hotel quarantine in New South Wales in April, according to the national genomics database AusTrakka.
There is no evidence to suggest the strain has already started to spread among the community in Australia, officials say.
The strain, also known to experts as C.37, is a 'variant of interest' because of its high transmissibility.
Professor Pablo Tsukayama, of Cayetano Heredia University in Lima, said the strain had 'exploded' in the country and was now responsible for 82 per cent of cases.
