London, Jan 26 (IANS): With new Covid-19 strains reported from several parts of the world giving fresh threats to the fight against the pandemic, a group of scientists is calling on governments to consider the continued use of strict control measures as the only way to reduce the evolution and spread of the new variants of the virus.

The experts -- at the University of East Anglia (UEA) in Britain, Earlham Institute in England and the University of Minnesota in the US -- warned that while governments are negotiating a "precarious balance" between saving the economy and preventing Covid-19 fatalities, stronger action now is the best way to mitigate against more serious outcomes from such virulent strains later.

While Covid-19 vaccine deployment is now underway, a threat to vaccine effectiveness comes from other emerging strains, both existing -- such as the UK, South Africa and Brazil variants -- and those yet to come.

In an editorial for the journal Virulence, Professors Cock van Oosterhout, Neil Hall, Hinh Ly, and its editor-in-chief Prof Kevin Tyler said, "continuing public health efforts to encourage vaccination as well as continued use of proper personal protective equipment (PPE), such as proper masking and maintaining safe social interactions, is of the utmost importance".

"Humanity is faced with a new reality. The faster we adapt, the better our long-term prospects. We must stop the evolution and spread of more virulent virus strains now. We, therefore, support public health policies with strict control measures in order to protect our public health system, our individual wellbeing, and our future."

They said that an increased virulence -- or higher R-value -- can also result from the virus evolving the ability to infect people for longer.

"Vaccination against a viral pathogen with such high prevalence globally is without precedent and we, therefore, have found ourselves in unchartered waters," the experts said.

"However, what we can be certain about is that, as long as the vaccine stays effective, a higher uptake of the vaccines will: reduce the number of Covid-19-related deaths, stem the spread of the transmissible strain of the virus, and reduce risk of the evolution of other, even more, virulent strains in the future.

"Furthermore, it is not unthinkable that vaccination of some domesticated animal species might also be necessary to curb the spread of the infection," they added.