Both the companies are pretty confident that their vaccines will be effective against the new strain found in UK and South Africa. It was only yesterday when the Moderna company released a press statement where they claimed that the vaccine induced immunity from their vaccine is capable of providing protection to the new variant of the Coronavirus. The rest of the companies meanwhile are conducting trials to asses he same and prove the efficacy of their vaccines too.
The following study suggests that Pfizer and Moderna COVID-19 vaccines are about 10 percent less effective against the South African variant of SARS-CoV-2.